ORCID Profile
0000-0002-5091-2513
Current Organisations
University of Birmingham
,
University of New South Wales
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Springer Science and Business Media LLC
Date: 11-2001
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 07-2016
Publisher: Springer Science and Business Media LLC
Date: 06-10-2010
Publisher: AIP Publishing
Date: 02-2011
DOI: 10.1063/1.3531992
Abstract: We report a study on multiferroic bismuth ferrite (BiFeO3, BFO)-ferromagnetic lanthanum strontium manganese oxide (La0.7Sr0.3MnO3, LSMO) epitaxial interfaces by scanning transmission electron microscopy-energy dispersive spectroscopy (STEM-EDS) and energy-filtered transmission electron microscopy (EFTEM). Epitaxial (001) oriented LSMO/BFO heterostructures were fabricated on a (001) strontium titanate (SrTiO3, STO) substrate using pulsed laser deposition (PLD). Different cooling conditions to room temperature (rapid or slow) were used to investigate the effect of fabrication conditions on the structural quality of the interfaces. The combined analysis of bright field transmission electron microscopy imaging, STEM-EDS and EFTEM data reveals that the LSMO-BFO heterostructure interface is free from any defects but the phases are chemically interdiffused over a length scale of ∼4 nm.
Publisher: Elsevier BV
Date: 09-1995
Publisher: Wiley
Date: 21-01-2004
Publisher: Elsevier BV
Date: 09-2021
Publisher: American Chemical Society (ACS)
Date: 09-12-2015
Publisher: Elsevier BV
Date: 07-2022
Publisher: Informa UK Limited
Date: 31-10-2018
Publisher: AIP Publishing
Date: 15-02-2006
DOI: 10.1063/1.2171772
Abstract: An alternative method for determining the lock-in angle φL for pinning of the vortices on extended defects has been developed. This method does not require any preassumed criterion for defining φL. Highly twinned Sm1+xBa2−xCu3O6+y single crystal was used for demonstrating the method. Appropriate scaling of the hysteresis loops measured for different angles between the field and twin planes in highly twinned SmBaCuO single crystal led to a clear discrimination between two vortex dynamics regimes. From this scaling, the lock-in angle was determined to be 6°±0.1° for the single crystal investigated. This method significantly reduces the uncertainty in determining the lock-in angle when compared to all the other currently employed methods.
Publisher: Elsevier BV
Date: 2009
Publisher: IOP Publishing
Date: 2009
Publisher: Elsevier BV
Date: 09-2015
Publisher: Springer Science and Business Media LLC
Date: 02-2005
Abstract: The solid-state reactions between Al and TiO 2 that occur during heating an Al/TiO 2 nanocomposite powder produced using high-energy mechanical milling have been studied using thermal analysis, x-ray diffractometry (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) in combination with compositional microanalysis. It has been found that Al and TiO 2 react in the temperature range from 650 to 800 °C, forming Al 3 Ti, but XRD analysis, SEM examination, and detailed TEM characterization of the powder particles heated to 800 °C show that the expected Al 2 O 3 does not form. However, α–Al 2 O 3 particles form during heating from 800 to 1000 °C. The possible reasons for the time gap between formation of Al 3 Ti and Al 2 O 3 are discussed.
Publisher: Elsevier BV
Date: 2013
Publisher: Inderscience Publishers
Date: 2003
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.MSEC.2019.110220
Abstract: ZnO nanoparticles doped with I and Ag were prepared via a solvothermal method. Characterizations of the as-synthesised s les were carried out using X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis spectrometry, Photoluminescence, transmission electron microscopy and scanning electron microscopy. The nanoparticles exhibit light absorption for wide spectra from ultra-violet (UV) to visible light. The antimicrobial efficacy was evaluated against Escherichia coli (MG1655) and Staphylococcus aureus (USA300) as models of Gram-negative and Gram-positive microorganisms, respectively. The double-doped nanoparticles demonstrated their potent efficacy against both types of microorganisms and they may have great potential in combating infectious diseases. More importantly, the insights into the mechanisms underlying the antimicrobial effects were revealed: synergistic effect of reactive oxygen species (ROS) generation and Ag
Publisher: IOP Publishing
Date: 17-06-2009
Publisher: Elsevier BV
Date: 2001
Publisher: Informa UK Limited
Date: 08-05-2018
DOI: 10.1080/09593330.2018.1468487
Abstract: Heavy metal contamination of crop lands surrounding mines in North Vietnam is a major environmental issue for both farmers and the population as a whole. Technology for the production of biochar at a village and household level has been successfully introduced into Vietnamese villages. This study was undertaken to determine if rice straw biochar produced in simple drum ovens could remediate contaminated land. Tests were also carried out to determine if biochar and apatite mixed together could be more effective than biochar alone. Incubation trials were carried out over 90 days in pots to determine the total changes in exchangeable Cd, Pb and Zn. Detailed tests were carried out to determine the mechanisms that bound the heavy metals to the biochar. It was found that biochar at 5% (BC5) and the mixture of biochar and apatite at 3% (BCA3) resulted in the greatest reduction of exchangeable forms of Cd, Pb and Zn. The increase in soil pH caused by adding biochar and apatite created more negative charge on the soil surface that promoted Pb, Zn and Cd adsorption. Heavy metals were mainly bound in the organic, Fe/Mn and carbonate fractions of the biochar and the mixture of biochar and apatite by either ion exchange, adsorption, dissolution recipitation and through substitution of cations in large organic molecules.
Publisher: Elsevier BV
Date: 07-2022
Publisher: World Scientific Pub Co Pte Lt
Date: 11-05-2018
DOI: 10.1142/S0218625X1850083X
Abstract: The development of new corrosion-resistant coatings is often challenging, but strongly driven by the potential benefits such coatings hold. A nanostructured Ta 2 N coating was deposited on a Ti–6Al–4V substrate in an Ar–N atmosphere using a double cathode glow discharge plasma method with the aim being to improve its corrosion resistance in oral environments. The microstructure of the coating was investigated by a range of methods including XRD, SEM-EDS and TEM. The as-deposited coating exhibited densely packed fibrous structure and the in idual fibers were composed of equiaxed grains with an average grain size [Formula: see text][Formula: see text]nm, arranged along the longitudinal axis of the in idual fibers. The electrochemical behavior of the Ta 2 N nanocrystalline coating was characterized in artificial saliva containing different NaF concentrations by a range of electrochemical techniques, including potentiodynamic measurement, EIS, capacitance and PZFC measurements. It was shown that the coating possessed superior corrosion resistance compared to uncoated Ti–6Al–4V, because its passive film exhibited higher stability against the fluoride ion attack.
Publisher: Elsevier BV
Date: 02-2007
Publisher: Elsevier BV
Date: 11-2016
Publisher: Wiley
Date: 02-06-2010
Publisher: IOP Publishing
Date: 14-02-2007
Publisher: Elsevier BV
Date: 03-2014
Publisher: Elsevier BV
Date: 04-1995
Publisher: Elsevier BV
Date: 02-2007
Publisher: FapUNIFESP (SciELO)
Date: 05-2012
DOI: 10.1590/S0100-204X2012000500007
Abstract: The objective of this work was to determine the contribution of dissolved organic carbon (DOC) from a biochar mineral complex (BMC), so as to better understand the interactions between DOC, biochar, clay, and minerals during thermal treatment, and the effects of BMC on amended soils. The BMC was prepared by heating a mixture of a H3PO4-treated saligna biochar from Acacia saligna, clays, other minerals, and chicken manure. The BMC was applied to a sandy loam soil in Western Australia, where wheat was grown. Liquid chromatography-organic carbon detection (LC-OCD) tests were carried out on water extracts from the untreated biochar, the BMC, the BMC-amended soil, and on a control soil to measure the DOC concentration. LC-OCD tests provide a fingerprint of the DOC, which allows the fractions of DOC to be determined. Thermal processing enhanced the reaction of the A. saligna biochar with manure, clays and minerals, and affected the distribution of the DOC fractions. Notably, the process leads to immobilization of hydrophobic DOC and to an increase in the concentration of low-molecular-weight neutrals in the BMC. The application of the BMC to soil increases the DOC in the amended soil, especially the biopolymer fraction.
Publisher: AIP Publishing
Date: 21-05-2001
DOI: 10.1063/1.1372207
Abstract: The mechanical deformation by spherical indentation of both crystalline InP and GaAs was characterized using cross-sectional transmission electron microscopy (XTEM) and atomic force microscopy. All load–unload curves show a discontinuity (or “pop in”) during loading. Slip bands oriented along {111} planes are visible in XTEM micrographs from residual indentations in both materials and no evidence of any phase transformations was found. Higher load indentations (35 mN for InP and 50 mN for GaAs) also revealed subsurface cracking. In contrast no cracking was found beneath a 25 mN InP indent although the hardness and modulus data are almost identical to those of the cracked s le. The subsurface cracks are thought to be nucleated by high stress concentrations caused by dislocation pileup.
Publisher: Springer Science and Business Media LLC
Date: 2008
Abstract: Indentations were performed on silicon using a Berkovich indenter at loads up to 12 mN, at temperatures from 20 to 135 °C. Transmission electron microscopy revealed crystalline silicon phases in the residual indentation imprint at and above 35 °C. Also, the first reconfirmation of the occurrence of Si-VIII during unloading was observed at temperatures of 100 and 125 °C. Interestingly, at 125 °C a cavity was also observed, and an unidentifiable phase was observed at 135 °C. The observations show the strong effect of temperature on pressure-induced phase transformation in silicon.
Publisher: IOP Publishing
Date: 27-08-2003
Publisher: Elsevier BV
Date: 10-2003
DOI: 10.1016/S0968-4328(03)00054-4
Abstract: Subtractive imaging in confocal fluorescence light microscopy is based on the subtraction of a suitably weighted widefield image from a confocal image. An approximation to a widefield image can be obtained by detection with an opened confocal pinhole. The subtraction of images enhances the resolution in-plane as well as along the optic axis. Due to the linearity of the approach, the effect of subtractive imaging in Fourier-space corresponds to a reduction of low spatial frequency contributions leading to a relative enhancement of the high frequencies. Along the direction of the optic axis this also results in an improved sectioning. Image processing can achieve a similar effect. However, a 3D volume dataset must be acquired and processed, yielding a result essentially identical to subtractive imaging but superior in signal-to-noise ratio. The latter can be increased further with the technique of weighted averaging in Fourier-space. A comparison of 2D and 3D experimental data analysed with subtractive imaging, the equivalent Fourier-space processing of the confocal data only, and Fourier-space weighted averaging is presented.
Publisher: Elsevier BV
Date: 07-2018
Publisher: Elsevier BV
Date: 11-2010
Publisher: Elsevier BV
Date: 2011
Publisher: Elsevier BV
Date: 10-2010
Publisher: Elsevier BV
Date: 2014
Publisher: Elsevier BV
Date: 02-2010
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 03-2006
Publisher: American Chemical Society (ACS)
Date: 07-09-2022
Abstract: Driven by the overuse of antibiotics, pathogenic infections, dominated by the rapid emergence of antibiotic resistant bacteria, have become one of the greatest current global health challenges. Thus, there is an urgent need to explore novel strategies that integrate multiple antibacterial modes to deal with bacterial infections. In this work, a Co(Ni,Ag)/Fe(Al,Cr)
Publisher: Elsevier BV
Date: 09-1996
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 09-2021
Publisher: Springer Science and Business Media LLC
Date: 1993
DOI: 10.1007/BF01151656
Publisher: Elsevier BV
Date: 03-2021
Publisher: Springer Science and Business Media LLC
Date: 12-2005
Publisher: AIP Publishing
Date: 22-10-2002
DOI: 10.1063/1.1517398
Abstract: Doping of MgB2 by nano-SiC and its potential for the improvement of flux pinning were studied for MgB2−x(SiC)x/2 with x=0, 0.2, and 0.3 and for 10 wt % nano-SiC-doped MgB2 s les. Cosubstitution of B by Si and C counterbalanced the effects of single-element doping, decreasing Tc by only 1.5 K, introducing intragrain pinning centers effective at high fields and temperatures, and significantly enhancing Jc and Hirr. Compared to the undoped s le, Jc for the 10 wt % doped s le increased by a factor of 32 at 5 K and 8 T, 42 at 20 K and 5 T, and 14 at 30 K and 2 T. At 20 K and 2 T, the Jc for the doped s le was 2.4×105 A/cm2, which is comparable to Jc values for the best Ag/Bi-2223 tapes. At 20 K and 4 T, Jc was twice as high as for the best MgB2 thin films and an order of magnitude higher than for the best Fe/MgB2 tapes. The magnetic Jc is consistent with the transport Jc which remains at 20 000 A/cm2 even at 10 T and 5 K for the doped s le, an order of magnitude higher than the undoped one. Because of such high performance, it is anticipated that the future MgB2 conductors will be made using a formula of MgBxSiyCz instead of pure MgB2.
Publisher: Elsevier BV
Date: 06-2006
Publisher: Springer Science and Business Media LLC
Date: 2008
Abstract: A diamondlike carbon (DLC) thin film was deposited onto a stainless steel substrate using a plasma-enhanced chemical vapor deposition (PECVD) process. Nanoindentation, coupled with focused-ion-beam (FIB) milling, was used to investigate contact-induced deformation and fracture in this coating system. Following initial elastic contact between the coating and the indenter and apparent plastic yield of the substrate, pop-ins were observed in the load–displacement curve, indicative of coating fracture. However, FIB cross-sectional images of indentations revealed the presence of ring, radial, and lateral cracks at loads much lower than the critical load for the first observed pop-ins. Finite element modeling was used, and the properties of the substrate and the film were calibrated by fitting the simulated load–displacement curves to experimental data. Then, based upon the experimental observations of damage evolution in this coating system, the stress distributions relevant to initiate ring, radial, and lateral cracks in the coating were ascertained. Furthermore, the effects of substrate yield stress and coating residual stress on the formation of these cracks were investigated.
Publisher: American Physical Society (APS)
Date: 21-07-2009
Publisher: Springer Science and Business Media LLC
Date: 08-1996
DOI: 10.1007/BF00352668
Publisher: AIP Publishing
Date: 09-12-2013
DOI: 10.1063/1.4842015
Abstract: The mechanical properties of human tooth enamel depend not only on test locations but also on the indentation depth. However, it remains uncertain what roles the depth-dependant properties play in mechanical performance of enamel. Here we reveal that a change in the mechanical properties of enamel, in particular its strength, with increasing indentation depth promotes inelastic deformation in material. In doing so, the severity and extent of stress concentration is reduced. Furthermore, we observed that following unloading, self-recovery occurs in enamel. These findings improve our understanding of the underlying mechanisms responsible for the remarkable resilience of enamel.
Publisher: Elsevier BV
Date: 09-2022
Publisher: IOP Publishing
Date: 20-06-2018
Publisher: Elsevier BV
Date: 11-1999
Publisher: Springer Science and Business Media LLC
Date: 10-2009
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 05-1992
Publisher: Elsevier BV
Date: 08-2022
Publisher: AIP Publishing
Date: 15-09-2005
DOI: 10.1063/1.2014937
Abstract: We have investigated experimentally the structure of disordered GaN films. The results suggest that it is not possible to stabilize an amorphous network in stoichiometric films, and the GaN instead consists of random-stacked nanocrystals of some 3-nm diameter. However, incorporation of 15% or more oxygen stabilizes an amorphous phase, which we attribute to the presence of nontetrahedral bonds centered on oxygen. The ionic favorability of heteropolar bonds and its strikingly simple constraint to even-membered rings are the likely causes of the instability of stoichiometric a-GaN.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.ULTSONCH.2019.104742
Abstract: To broaden the scope of non-aerospace applications for titanium-based alloys, both hexagonal C40 binary TaSi
Publisher: Elsevier BV
Date: 11-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2004
Publisher: Elsevier BV
Date: 11-2010
Publisher: Elsevier BV
Date: 08-2021
Publisher: Springer Science and Business Media LLC
Date: 04-2005
Abstract: Preliminary investigations of a new high-strength alloy of composition Fe 30 Ni 20 Mn 25 Al 25 (at.%) are described in this paper. The as-cast alloy consisted of a periodic two-phase microstructure of interconnected, ∼50-nm-wide rods with fully coherent {100} interfaces, strongly suggestive of formation by a B2 to [(B2 + body-centered cubic (bcc)] spinodal decomposition. The (Ni,Al)-rich B2 and (Fe,Mn)-rich bcc phases differed in lattice parameter by .5%. Hardness and yield strength of the as-cast alloy were found to be approximately 500 VPN and 1500 MPa, respectively, and increased by more than 50% after annealing at 550 °C for several days. (Fe,Mn)-rich precipitates with a β–Mn structure were observed in the annealed material.
Publisher: Elsevier BV
Date: 02-2012
Publisher: American Chemical Society (ACS)
Date: 17-03-2011
DOI: 10.1021/CG101623N
Publisher: Trans Tech Publications, Ltd.
Date: 23-05-2014
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.783-786.2549
Abstract: This paper presents an overview of the microstructures found in a range of two-phase FeNiMnAl alloys ranging from near-equiatomic very high-strength nanostructured alloys, such Fe 30 Ni 20 Mn 25 Al 25 , to more ductile f.c.c./B2 alloys, such as Fe 30 Ni 20 Mn 35 Al 15 . The effect of annealing at 823 K on the room temperature hardness is presented together with the temperature dependence of the yield strength.
Publisher: Springer Science and Business Media LLC
Date: 12-2006
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 06-2019
Publisher: AIP Publishing
Date: 15-04-2006
DOI: 10.1063/1.2172558
Abstract: Electronic transport measurements have been carried out on superconducting MgB2∕Mg2Si multilayer film, using a standard four-probe method in perpendicular and parallel applied fields. The film, which was prepared by pulsed-laser deposition, has a layered structure with each MgB2 layer being 40–50 nm thick and the Mg2Si interlayers about 5 nm thick. The flux flow activation energy is deduced from the resistivity-temperature curves using an Arrhenius fit. The results show a clearly enhanced anisotropy of the vortex activation energy in the multilayered film. The irreversibility field and the vortex activation energy are significantly increased in parallel fields.
Publisher: AIP Publishing
Date: 11-2009
DOI: 10.1063/1.3255999
Abstract: We have investigated nanoindentation-induced plastic deformation in amorphous germanium (a-Ge) prepared by high-energy self-ion implantation. Using cross-sectional transmission electron microscopy, micro-Raman spectroscopy, and force-displacement curve analysis, we find strong evidence for a pressure-induced metallic phase transformation during indentation. Crystalline diamond-cubic Ge-I is observed in residual indents. Relaxed and unrelaxed structural states of a-Ge exhibit similar behavior on loading, but transform at different pressures on unloading. Both forms are markedly softer mechanically than crystalline Ge. These results assist in furthering the understanding of the intriguing phenomenon known as “explosive crystallization.”
Publisher: Elsevier BV
Date: 2014
Publisher: Elsevier BV
Date: 03-2017
Publisher: Elsevier BV
Date: 10-2011
Publisher: Springer Science and Business Media LLC
Date: 12-1989
DOI: 10.1007/BF00544494
Publisher: Elsevier BV
Date: 12-2009
Publisher: Elsevier BV
Date: 06-2006
Publisher: Elsevier BV
Date: 10-2016
Publisher: Wiley
Date: 22-07-2016
Publisher: Elsevier BV
Date: 10-2017
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3TA11813D
Publisher: AIP Publishing
Date: 20-08-2018
DOI: 10.1063/1.5042148
Abstract: A CrCoNi medium entropy alloy thin film is fabricated using magnetron sputtering. It exhibits a unique hierarchical nanostructure, featuring (1) a high density of planar defects (mostly stacking faults plus a small number of twin boundaries), (2) a dual-phase configuration (a mix of face-centred-cubic and hexagonal-close-packed), and (3) vertically aligned, textured nanocolumns, each with a width of ∼100 nm. The hierarchical nanostructure in this study is original, especially for its dual phase combination, since the bulk CrCoNi medium entropy alloy generally presents a single phase face-centred-cubic structure. The CrCoNi film shows a hardness quadruple that of its face-centred-cubic structured counterpart. The formation and its role of the hierarchical nanostructure in producing such mechanical strength are discussed.
Publisher: Elsevier BV
Date: 06-2018
Publisher: Informa UK Limited
Date: 06-2013
Publisher: Elsevier BV
Date: 08-2011
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: IOP Publishing
Date: 2009
Publisher: Elsevier BV
Date: 11-2011
Publisher: Elsevier BV
Date: 06-1989
Publisher: Elsevier BV
Date: 04-2013
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7TC05841A
Abstract: Epitaxial mixed-phase BFO//LAO thin films with enhanced electromechanical performance were successfully synthesized by chemical solution deposition.
Publisher: AIP Publishing
Date: 11-2011
DOI: 10.1063/1.3658628
Abstract: We investigate the structure of magnetron-sputtered (MS) amorphous silicon (a-Si) prepared under standard deposition conditions and compare this to pure ion-implanted (II) a-Si. The structure of both films is characterized in their as-prepared and thermally annealed states. Significant differences are observed in short- and medium-range order following thermal annealing. Whereas II a-Si undergoes structural relaxation toward a continuous random network, MS a-Si exhibits little change. Cross-sectional transmission electron microscopy reveals the presence of nanopores in the MS film consistent with reduced mass-density. Therefore, the short- and medium-range order of annealed, MS a-Si is tentatively attributed to these pores.
Publisher: Elsevier BV
Date: 05-2012
Publisher: Elsevier BV
Date: 05-2004
Publisher: Royal Society of Chemistry (RSC)
Date: 2007
DOI: 10.1039/B711705A
Publisher: Wiley
Date: 31-05-2018
Abstract: Sodium (Na) metal is one of the most promising electrode materials for next-generation low-cost rechargeable batteries. However, the challenges caused by dendrite growth on Na metal anodes restrict practical applications of rechargeable Na metal batteries. Herein, a nitrogen and sulfur co-doped carbon nanotube (NSCNT) paper is used as the interlayer to control Na nucleation behavior and suppress the Na dendrite growth. The N- and S-containing functional groups on the carbon nanotubes induce the NSCNTs to be highly "sodiophilic," which can guide the initial Na nucleation and direct Na to distribute uniformly on the NSCNT paper. As a result, the Na-metal-based anode (Na/NSCNT anode) exhibits a dendrite-free morphology during repeated Na plating and striping and excellent cycling stability. As a proof of concept, it is also demonstrated that the electrochemical performance of sodium-oxygen (Na-O
Publisher: Wiley
Date: 29-07-2010
Publisher: IOP Publishing
Date: 05-04-2005
Publisher: Wiley
Date: 25-01-2019
Publisher: Springer Science and Business Media LLC
Date: 06-2004
Publisher: Informa UK Limited
Date: 02-2012
Publisher: Elsevier BV
Date: 03-2013
DOI: 10.1016/J.CHEMOSPHERE.2012.11.063
Abstract: In this study biochar mixtures comprising a Jarrah-based biochar, chicken litter (CL), clay and other minerals were thermally treated, via torrefaction, at moderate temperatures (180 and 220 °C). The objectives of this treatment were to reduce N losses from CL during processing and to determine the effect of both the type of added clay and the torrefaction temperature on the structural and chemical properties of the final product, termed as an enhanced biochar (EB). Detailed characterisation indicated that the EBs contained high concentrations of plant available nutrients. Both the nutrient content and plant availability were affected by torrefaction temperature. The higher temperature (220 °C) promoted the greater decomposition of organic matter in the CL and dissociated labile carbon from the Jarrah-based biochar, which produced a higher concentration of dissolved organic carbon (DOC). This DOC may assist to solubilise mineral P, and may also react with both clay and minerals to block active sites for P adsorption. This subsequently resulted in higher concentrations of plant available P. Nitrogen loss was minimised, with up to 73% of the initial total N contained in the feedstock remaining in the final EB. However, N availability was affected by both torrefaction temperature and the nature of the clay minerals added.
Publisher: Elsevier BV
Date: 12-1990
Publisher: Wiley
Date: 17-03-2006
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 12-2022
Publisher: MDPI AG
Date: 13-09-2018
DOI: 10.3390/MET8090719
Abstract: Nanoindentation is a commonly used method to measure the hardness of surfaces with thin layers, and is especially useful in studying the change in mechanical properties of ion irradiated materials. This research compares two different methods of nanoindentation to study the changes in hardness resulting from ion irradiation of SS316 alloy. The s les were irradiated by He2+ ions at beam energies of 1, 2, and 3 MeV, respectively. The first method involves the indentation of the irradiated surface perpendicular to it using the continuous stiffness mode (CSM), while the second applies the indents on an oblique surface, accessing an inclined cross-section of the irradiated material. Finite element modelling has been used to further illuminate the deformation processes below the indents in the two methods. The hardness profiles obtained from the two nanoindentation methods reveal the differences in the outcomes and advantages of the respective procedures, and provide a useful guideline for their applicability to various experimental conditions. It is shown through an in depth analysis of the results that the ‘top-down’ method is preferable in the case when the ion irradiation energy, or, equivalently, the irradiated depth is small, due to its greater spatial resolution. However, the oblique cross section method is more suitable when the ion irradiation energy is MeV, since it allows a more faithful measurement of hardness as a function of dose, as the plastic field is much smaller and more sensitive to local hardness values.
Publisher: Elsevier BV
Date: 10-2004
Publisher: Springer Science and Business Media LLC
Date: 02-2008
Abstract: Giant “pop-in” displacements are observed in crystalline silicon and germanium during high-load nanoindentation with a spherical diamond tip. These events are consistent with material removal triggered by lateral cracking during loading, which poses a hazard to microelectromechanical systems (MEMS) operation. We examine the scaling of the pop-in displacements as a function of peak indentation load and demonstrate a correlation with the depth of the plastic contact zone. We argue that giant pop-ins may occur in a broad range of highly brittle materials.
Publisher: Informa UK Limited
Date: 2003
Publisher: Elsevier BV
Date: 05-2014
DOI: 10.1016/J.JHAZMAT.2014.03.017
Abstract: Heavy metal contamination in croplands has been a serious concern because of its high health risk through soil-food chain transfer. A field experiment was conducted in 2010-2012 in a contaminated rice paddy in southern China to determine if bioavailability of soil Cd and Pb could be reduced while grain yield was sustained over 3 years after a single soil amendment of wheat straw biochar. Contaminated biochar particles were separated from the biochar amended soil and microscopically analyzed to help determine where, and how, metals were immobilized with biochar. Biochar soil amendment (BSA) consistently and significantly increased soil pH, total organic carbon and decreased soil extractable Cd and Pb over the 3 year period. While rice plant tissues' Cd content was significantly reduced, depending on biochar application rate, reduction in plant Pb concentration was found only in root tissue. Analysis of the fresh and contaminated biochar particles indicated that Cd and Pb had probably been bonded with the mineral phases of Al, Fe and P on and around and inside the contaminated biochar particle. Immobilization of the Pb and Cd also occurred to cation exchange on the porous carbon structure.
Publisher: Elsevier BV
Date: 07-2020
Publisher: The Electrochemical Society
Date: 2006
DOI: 10.1149/1.2345550
Publisher: Elsevier BV
Date: 11-2006
Publisher: MDPI AG
Date: 11-11-2020
DOI: 10.3390/S20226432
Abstract: RuO2 thin films were prepared using magnetron sputtering under different deposition conditions, including direct current (DC) and radio frequency (RF) discharges, metallic/oxide cathodes, different substrate temperatures, pressures, and deposition times. The surface morphology, residual stress, composition, crystal structure, mechanical properties, and pH performances of these RuO2 thin films were investigated. The RuO2 thin films RF sputtered from a metallic cathode at 250 °C exhibited good pH sensitivity of 56.35 mV H. However, these films were rougher, less dense, and relatively softer. However, the DC sputtered RuO2 thin film prepared from an oxide cathode at 250 °C exhibited a pH sensitivity of 57.37 mV H with a smoother surface, denser microstructure and higher hardness. The thin film RF sputtered from the metallic cathode exhibited better pH response than those RF sputtered from the oxide cathode due to the higher percentage of the RuO3 phase present in this film.
Publisher: Wiley
Date: 14-01-2011
Publisher: American Chemical Society (ACS)
Date: 03-01-2023
Publisher: Elsevier BV
Date: 06-2011
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 05-2021
Publisher: Trans Tech Publications, Ltd.
Date: 12-2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.702-703.161
Abstract: Lamellar bands are the primary structural features in accumulative roll bonding (ARB) of sheet metals. The structural refinement in ARB sheets occur by forming a dense distribution of lamellar band boundaries. The lamellar band boundaries initiate as low angle interfaces, parallel to the existing lamellar band boundaries, irrespective of the crystallographic orientations of the parent lamellar bands. From an extensive investigation it was found that the transverse directions across the lamellar band boundaries are rotated by an angle equal to their misorientations. Such a phenomenon is not sustained when the boundaries turn to high angle.
Publisher: AIP Publishing
Date: 15-04-2011
DOI: 10.1063/1.3569858
Abstract: We investigate the interfacial structure of PbZr0.20Ti0.80O3 (PZT)/La0.67Sr0.33MnO3 (LSMO)/SrTiO3 heterostructures by combining low-magnification transmission electron microscopy imaging and spectroscopy techniques with high-resolution spherical-aberration corrected scanning transmission electron microscopy imaging, geometrical phase analysis, and spectroscopy results. For certain thickness regimes, the interface between PZT and LSMO is found to have a significant density of planar defects at the interface. Both A-site cation (Pb) diffusivity and highly inhomogeneous local strains are observed at the boundaries of the defect areas. It is proposed that Pb is incorporated as PbO Ruddlesden–Popper planar fault within the LSMO. These results underline the importance of chemical fluctuations caused by long-range strain fields associated with defect cores.
Publisher: Elsevier BV
Date: 2014
Publisher: Elsevier BV
Date: 05-2013
Publisher: Elsevier BV
Date: 2023
Publisher: Wiley
Date: 2007
DOI: 10.1002/JEMT.20406
Abstract: The application of focused ion beam instrumentation in the generation of three-dimensional microstructural data is described. The methodologies used to acquire and manipulate this data are explained, and the technique is illustrated by a number of ex les from the material sciences. The limitations of this method, and practical pointers to the generation of meaningful data, are also discussed.
Publisher: AIP Publishing
Date: 18-09-2006
DOI: 10.1063/1.2355467
Abstract: The authors investigated the doping effects of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) on the Tc, lattice parameters, Jc(B), microstructure, and Hc2 of MgB2∕Fe wire. These effects systematically showed the following sequence for Tc and the a axis: the SWCNT doped wire& the MWshortCNT doped wire& the MWlongCNT doped wire& undoped wire, while Jc(B) followed the sequence of the SWCNT doped wire& the MWshortCNT doped wire& the MWlongCNT doped wire& undoped wire. A dominating mechanism behind all these findings is the level of C substitution for B in the lattice.
Publisher: American Chemical Society (ACS)
Date: 28-05-2014
DOI: 10.1021/NL500397Y
Abstract: The electrochemical performance of lithium-oxygen (Li-O2) batteries awaits dramatic improvement in the design of porous cathode electrodes with sufficient spaces to accommodate the discharge products and discovery of effective cathode catalysts to promote both oxygen reduction reactions and oxygen evolution reactions. Herein, we report the synthesis of porous graphene with different pore size architectures as cathode catalysts for Li-O2 batteries. Porous graphene materials exhibited significantly higher discharge capacities than that of nonporous graphene. Furthermore, porous graphene with pore diameter around 250 nm showed the highest discharge capacity among the porous graphene with the small pores (about 60 nm) and large pores (about 400 nm). Moreover, we discovered that addition of ruthenium (Ru) nanocrystals to porous graphene promotes the oxygen evolution reaction. The Ru nanocrystal-decorated porous graphene exhibited an excellent catalytic activity as cathodes in Li-O2 batteries with a high reversible capacity of 17,700 mA h g(-1), a low charge/discharge overpotential (about 0.355 V), and a long cycle life up to 200 cycles (under the curtaining capacity of 1000 mAh g(-1)). The novel porous graphene architecture inspires the development of high-performance Li-O2 batteries.
Publisher: Elsevier BV
Date: 04-2003
Publisher: Elsevier BV
Date: 12-2003
Publisher: Oxford University Press (OUP)
Date: 31-07-2006
DOI: 10.1017/S1431927606062866
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.SCITOTENV.2022.155021
Abstract: Continual application of nitrogen (N), phosphorous (P) and potassium (K) fertilizer may not return a profit to farmers due to the costs of application and the loss of NPK from soil in various ways. Thus, a combination of NPK granule with a porous biochar (termed here as BNPK) appears to offer multiple benefits resulting from the excellent properties of biochar. Given the lack of information on the properties of NPK and BNPK fertilizers, it is necessary to investigate the characteristics of both to achieve a good understanding of why BNPK granule is superior to NPK granule. Therefore, this study aims to investigate the characteristics of a maize straw biochar mixed with NPK granule, before and after application to soil, and compare them to those for a commercial NPK granule. The BNPK granule, with a greater surface area and porosity, showed a higher capacity to store and donate electrons than the NPK granule. Relatively lower concentrations of Ca, P, K, Si and Mg were dissolved from the BNPK, indicating the ability of the BNPK granule to maintain these mineral elements and reduce dissolution rate. To study the nutrient storage mechanism of the BNPK granule in the soil, short- and long-term leaching experiments were conducted. During the experiments, organo-mineral clusters, comprising C, P, K, Si, Al and Fe, were formed on the surface and inside the biochar pores. However, BNPK was not effective in reducing N leaching, in the absence of plants, in a red chromosol soil.
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.SCITOTENV.2022.154174
Abstract: Biochar-based compound fertilisers (BCF) are gaining increasing attention as they are cost-effectiveness and improve soil fertility and crop yield. However, little is known about the mechanisms by which micron-size BCF particles enhance crop growth. In the present study, Wuyunjing7 rice seedlings were exposed to micron-size particles of wheat straw-based BCF (mBCF) diffused through a 25-μm nylon mesh. The control was fertilised with urea, diammonium phosphate, and potassium chloride to ensure that both treatments received comparables level of N, P, and K. The effects of mBCF on rice seedling growth were evaluated by determining the changes in nitrogen uptake and utilisation via nitrogen content measurements, short-term
Publisher: Elsevier BV
Date: 11-2009
Publisher: Springer Science and Business Media LLC
Date: 05-2010
Abstract: The effect of the presence of diamondlike carbon coatings deposited on (100) Si substrates on the deformation mechanisms operating in the silicon substrate during contact loading have been investigated by both cross-sectional transmission electron microscopy and modeling of the stresses generated beneath the indenter tip. The observed subsurface microstructures were correlated to the Tresca shear stress and the hydrostatic stress generated in the silicon substrate beneath the indenter tip. The presence of the coating altered the stresses generated in the substrate, and changed the deformation mechanism from one of principally phase transformation in uncoated Si to predominantly dislocation motion in the silicon substrate for the diamondlike C–Si system. The magnitude and distribution of the shear and hydrostatic stresses in the substrate were found to depend on both the indentation load and the thickness of the coating. Furthermore, the observed width of deformation, parallel to the interface, which was found to increase with coating thickness, was correlated to the wider distribution of the Tresca shear stress in the substrate brought about by the presence of the coating.
Publisher: American Chemical Society (ACS)
Date: 08-03-2016
Publisher: Springer Science and Business Media LLC
Date: 03-03-2012
Publisher: Informa UK Limited
Date: 2006
Publisher: Elsevier BV
Date: 04-2012
Publisher: Elsevier BV
Date: 04-2016
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 2009
Publisher: Elsevier BV
Date: 12-1991
Publisher: Oxford University Press (OUP)
Date: 24-07-2003
Publisher: Wiley
Date: 29-12-2019
Abstract: Benefiting from the natural abundance and low standard redox potential of potassium, potassium-ion batteries (PIBs) are regarded as one of the most promising alternatives to lithium-ion batteries for low-cost energy storage. However, most PIB electrode materials suffer from sluggish thermodynamic kinetics and dramatic volume expansion during K
Publisher: Wiley
Date: 05-12-2016
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.SCITOTENV.2017.09.200
Abstract: Recent studies have demonstrated the importance of the nutrient status of biochar and soils prior to its inclusion in particular agricultural systems. Pre-treatment of nutrient-reactive biochar, where nutrients are loaded into pores and onto surfaces, gives improved yield outcomes compared to untreated biochar. In this study we have used a wide selection of spectroscopic and microscopic techniques to investigate the mechanisms of nutrient retention in a high temperature wood biochar, which had negative effects on Chenopodium quinoa above ground biomass yield when applied to the system without prior nutrient loading, but positive effects when applied after composting. We have compared non-composted biochar (BC) with composted biochar (BCC) to elucidate the differences which may have led to these results. The results of our investigation provide evidence for a complex series of reactions during composting, where dissolved nutrients are first taken up into biochar pores along a concentration gradient and through capillary action, followed by surface sorption and retention processes which block biochar pores and result in deposition of a nutrient-rich organomineral (plaque) layer. The lack of such pretreatment in the BC s les would render it reactive towards nutrients in a soil-fertilizer system, making it a competitor for, rather than provider of, nutrients for plant growth.
Publisher: American Chemical Society (ACS)
Date: 02-11-2016
Abstract: The nanoscale origins of ferroelastic domain wall motion in ferroelectric multilayer thin films that lead to giant electromechanical responses are investigated. We present direct evidence for complex underpinning factors that result in ferroelastic domain wall mobility using a combination of atomic-level aberration corrected scanning transmission electron microscopy and phase-field simulations in model epitaxial (001) tetragonal (T) PbZr
Publisher: Elsevier BV
Date: 08-2022
Publisher: Informa UK Limited
Date: 09-1997
Publisher: Elsevier BV
Date: 10-2003
Publisher: Elsevier BV
Date: 05-2009
DOI: 10.1016/J.JBIOMECH.2009.02.004
Abstract: Tooth enamel is the stiffest tissue in the human body with a well-organized microstructure. Developmental diseases, such as enamel hypomineralisation, have been reported to cause marked reduction in the elastic modulus of enamel and consequently impair dental function. We produce evidence, using site-specific transmission electron microscopy (TEM), of difference in microstructure between sound and hypomineralised enamel. Built upon that, we develop a mechanical model to explore the relationship of the elastic modulus of the mineral-protein composite structure of enamel with the thickness of protein layers and the direction of mechanical loading. We conclude that when subject to complex mechanical loading conditions, sound enamel exhibits consistently high stiffness, which is essential for dental function. A marked decrease in stiffness of hypomineralised enamel is caused primarily by an increase in the thickness of protein layers between apatite crystals and to a lesser extent by an increase in the effective crystal orientation angle.
Publisher: Springer Science and Business Media LLC
Date: 18-02-2010
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.SCITOTENV.2019.134424
Abstract: Over use of N fertilizers, most commonly as urea, had been seriously concerned as a major source of radiative N (Nr) for severe environment impacts through leaching, volatilization, and N
Publisher: Springer International Publishing
Date: 2016
Publisher: AIP Publishing
Date: 18-07-2003
DOI: 10.1063/1.1586467
Abstract: We investigated the effect of SiC nanoparticle doping on the crystal lattice structure, critical temperature Tc, critical current density Jc, and flux pinning in MgB2 superconductor. A series of MgB2−x(SiC)x/2 s les with x=0–1.0 were fabricated using an in situ reaction process. The contraction of the lattice and depression of Tc with increasing SiC doping level remained rather small most likely due to the counterbalancing effect of Si and C co-doping. The high level Si and C co-doping allowed the creation of intragrain defects and highly dispersed nanoinclusions within the grains which can act as effective pinning centers for vortices, improving Jc behavior as a function of the applied magnetic field. The enhanced pinning is mainly attributable to the substitution-induced defects and local structure fluctuations within grains. A pinning mechanism is proposed to account for different contributions of different defects in MgB2−x(SiC)x/2 superconductors.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.ULTSONCH.2018.09.008
Abstract: To investigate the effects of Al alloying on the erosion-corrosion resistance of β-Ta
Publisher: Elsevier BV
Date: 09-2017
Publisher: IOP Publishing
Date: 19-10-2007
Publisher: Elsevier BV
Date: 11-2016
Publisher: Elsevier BV
Date: 07-2004
Publisher: Informa UK Limited
Date: 08-1995
Publisher: Springer Science and Business Media LLC
Date: 2001
Publisher: AIP Publishing
Date: 15-06-2009
DOI: 10.1063/1.3151967
Abstract: There is considerable controversy over the deformation behavior of germanium (Ge) under nanoindentation using a sharp diamond tip, with a erse range of observations that suggest competing mechanisms. Here we show the deformation mechanism of Ge can be controlled by the rate of applied load. Loading rate is varied over three orders of magnitude using depth-sensing nanoindentation. At slow loading rates, shear-induced plasticity is observed. At rapid loading rates (& mN s−1), pressure-induced phase transformations are detected by ex situ micro-Raman spectroscopy and transmission electron microscopy. This switch in the deformation mechanism is due to the differing rate sensitivities of the respective deformation modes, shear-induced plasticity or pressure-induced phase transformation.
Publisher: Elsevier BV
Date: 05-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4TC02064B
Abstract: A combination of atom column-by-column scanning transmission electron microscopy and density functional theory shows how epitaxial strain alters the local electronic structure in mixed phase bismuth ferrite thin films.
Publisher: Springer Science and Business Media LLC
Date: 13-03-2015
DOI: 10.1038/SREP09094
Abstract: α-MnO 2 nanotubes were fabricated using a hydrothermal technique. Li, Na and K ions were introduced into MnO 2 nanotubes to tailor their magnetic properties. It was found that with a doping concentration lower than 12 at%, the nanotubes showed ferromagnetic-like ordering at low temperature ( K), while antiferromagnetic coupling dominated their physical behavior with doping concentrations beyond 12 at%. Such experimental phenomenon was in very good agreement with associated first principle calculations. The ferromagnetic-like ordering originates from the breaking of equivalence between two different Mn-O octahedrals in α-MnO 2 due to the filling of alkaline ions in the tunnels. Both small charge transfer and lattice distortion play important roles in the ferromagnetic ordering.
Publisher: Elsevier BV
Date: 07-2012
Publisher: Informa UK Limited
Date: 2003
DOI: 10.1179/MHT.2003.061
Publisher: Elsevier BV
Date: 05-2005
Publisher: AIP Publishing
Date: 02-01-2006
DOI: 10.1063/1.2159572
Abstract: We obtained a MgB2∕Mg2Si multilayer structure by sequentially switching a stoichiometric MgB2 target and a Si target during off-axis pulsed-laser deposition. The transmission-electron-microscopic cross-sectional image of the resulting film exhibits a layered structure with each MgB2 layer being 40–50nm thick and the Mg2Si interlayers about 5nm thick. A clearly enhanced anisotropy in the irreversibility lines and the vortex activation energy was observed. Pinning and the flux flow activation energy are significantly increased in parallel applied fields.
Publisher: Springer Science and Business Media LLC
Date: 07-01-2021
Publisher: Springer Science and Business Media LLC
Date: 28-04-2014
DOI: 10.1557/JMR.2014.79
Publisher: Trans Tech Publications, Ltd.
Date: 04-2003
Publisher: Elsevier BV
Date: 05-2017
Publisher: Springer Science and Business Media LLC
Date: 06-2009
Abstract: Phase transformations in (111) Si after spherical indentation have been investigated by cross-sectional transmission electron microscopy. Even at an indentation load of 20 mN, a phase transformation zone including the high-pressure crystalline Si phases was observed within the residual imprints. The volume of the transformation zone, as well as that of the crystalline phases increased with the indentation load. Below the transformation zone, slip was found to occur on {311} planes rather than on {111} planes, usually observed on indentation of (100) Si. The distribution of defects was asymmetric, and for indentation loads up to 80 mN, their density was significantly lower than that reported for (100) Si. The experimental observations correlated well with modeling of the applied stress through ELASTICA.
Publisher: Springer Science and Business Media LLC
Date: 28-04-2010
Publisher: Elsevier BV
Date: 2004
Publisher: Elsevier BV
Date: 04-2016
Publisher: Elsevier BV
Date: 06-2012
Publisher: Elsevier BV
Date: 03-2019
Publisher: Elsevier BV
Date: 07-2014
Publisher: Elsevier BV
Date: 07-2018
Publisher: Springer Science and Business Media LLC
Date: 06-05-2020
Publisher: Elsevier BV
Date: 09-2004
Publisher: Elsevier BV
Date: 06-2008
Publisher: Elsevier BV
Date: 06-2010
Publisher: World Scientific Pub Co Pte Lt
Date: 08-2004
DOI: 10.1142/S0219581X04002383
Abstract: Polycrystalline MgB 2 s les with 0, 5, 10, and 20 wt% nano- Y - ZrO 2 (YSZ) powder addition were prepared by short time, as little as several minutes, or long time in-situ reaction process. The phases, microstructures and flux pinning behaviors were characterized using X-ray diffractometry (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM) and Magnetic Measurements. Results indicated that nano-YSZ particles included in MgB 2 grains. S les doped with 10wt% YSZ powders showed new record of critical current density J c as high as 1×10 6 and 4×10 6 A/cm 2 in low magnetic fields at 30 and 20K, respectively. However, the J c drops faster compared to that made by long time sintering s les. It is proposed that the improved J c in low fields was due to the enhanced density of the s le, which was caused by the YSZ nano-particle inclusion.
Publisher: Springer Science and Business Media LLC
Date: 22-04-2010
Publisher: Wiley
Date: 14-09-2010
Publisher: AIP Publishing
Date: 11-05-2005
DOI: 10.1063/1.1929874
Abstract: The mechanical properties of zinc oxide epitaxial layers grown on a- and c-axis sapphire have been studied by spherical nanoindentation and cross-sectional transmission electron microscopy. As-grown threading dislocations, which are characteristic of epitaxial material, combined with the presence of the much harder, underlying substrate are found to have a significant effect on the mechanical behavior of ZnO epilayers as compared to bulk material. Epilayer material is found to be significantly harder than its bulk counterpart. For a-axis epilayers, analysis of load–unload data yields a hardness of 6.6±1.2GPa, and 5.75±0.8GPa for c-axis layers. We attribute this increased hardness to strain compensation via the presence of as-grown defects. These defects inhibit the slip mechanism responsible for relative softness of bulk single crystals. The absence of pop-in events from analyzed continuous-load nanoindentation data is further evidence for strain compensation by native defects within the epilayers. Large variations in the spread of collected data are indicative of inhomegenity in the epilayers.
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 07-2013
Publisher: Walter de Gruyter GmbH
Date: 12-2009
DOI: 10.3139/146.110223
Abstract: A commercial purity Al alloy and an Al-0.3Sc (wt.%) alloy, the latter in either the supersaturated or artificially aged condition, were accumulative roll bonded at either 200 or 350°C to high strain to generate sheet materials consisting of 32 or 64 alternating layers of Al and Al(Sc). The microstructure and texture of the processed materials were investigated mainly using electron backscattered diffraction scanning electron microscopy and transmission electron microscopy. The deformation microstructure and texture of these two alloy combinations were strongly influenced by both the initial heat treatment condition of the Al(Sc) alloy whereby large-scale shear bands were generated during rolling when a dispersion of fine Al 3 Sc particles is present in the Al(Sc) layers. The effect of initial microstructure and processing temperature affected the subsequent recrystallization microstructure and texture of the Al/Al(Sc) composite during annealing at 350°C. Here, the Al(Sc) layers remain unrecrystallized in all materials with the Al layers undergoing continuous and discontinuous recrystallization after low and high temperature ARB, respectively. The lack of recrystallization in the Al(Sc) layers generated an alternating recrystallized/recovered microstructure in all materials.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2TA00510G
Publisher: Elsevier BV
Date: 06-2022
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 08-2005
Publisher: Springer Science and Business Media LLC
Date: 12-1994
DOI: 10.1007/BF00732277
Publisher: Elsevier BV
Date: 12-1991
Publisher: Elsevier BV
Date: 07-2014
Publisher: Elsevier BV
Date: 2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C1JM14744G
Publisher: Iron and Steel Institute of Japan
Date: 2017
Publisher: Wiley
Date: 05-07-2012
Publisher: Elsevier BV
Date: 10-2014
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/SR10009
Abstract: Interactions between biochar, soil, microbes, and plant roots may occur within a short period of time after application to the soil. The extent, rates, and implications of these interactions, however, are far from understood. This review describes the properties of biochars and suggests possible reactions that may occur after the addition of biochars to soil. These include dissolution–precipitation, adsorption–desorption, acid–base, and redox reactions. Attention is given to reactions occurring within pores, and to interactions with roots, microorganisms, and soil fauna. Examination of biochars (from chicken litter, greenwaste, and paper mill sludges) weathered for 1 and 2 years in an Australian Ferrosol provides evidence for some of the mechanisms described in this review and offers an insight to reactions at a molecular scale. These interactions are biochar- and site-specific. Therefore, suitable experimental trials—combining biochar types and different pedoclimatic conditions—are needed to determine the extent to which these reactions influence the potential of biochar as a soil amendment and tool for carbon sequestration.
Publisher: AIP Publishing
Date: 13-11-2006
DOI: 10.1063/1.2388126
Abstract: A magnetic field of up to 12T was applied during the sintering process of pure MgB2 and carbon nanotube (CNT) doped MgB2 wires. The authors have demonstrated that magnetic field processing results in grain refinement, homogeneity, and enhancement in Jc(H) and Hirr. The extent of improvement in Jc increases with increasing field. The Jc for a 10T field processed CNT doped s le increases by a factor of 3 at 10K and 8T and at 20K and 5T, respectively. Hirr for the 10T field processed CNT doped s le reached 9T at 20K, which exceeded the best value of SiC doped MgB2 at 20K. Magnetic field processing reduces the resistivity in CNT doped MgB2, straightens the entangled CNTs, and improves the adherence between CNTs and the MgB2 matrix.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 03-1995
Publisher: MDPI AG
Date: 21-07-2015
Publisher: Elsevier BV
Date: 06-2012
Publisher: Elsevier BV
Date: 05-2008
Publisher: Iron and Steel Institute of Japan
Date: 2014
Publisher: Elsevier BV
Date: 02-2018
Publisher: American Chemical Society (ACS)
Date: 29-06-2016
Abstract: Dramatic changes in molecular structure, degradation pathway, and porosity of biochar are observed at pyrolysis temperatures ranging from 250 to 550 °C when bamboo biomass is pretreated by iron-sulfate-clay slurries (iron-clay biochar), as compared to untreated bamboo biochar. Electron microscopy analysis of the biochar reveals the infusion of mineral species into the pores of the biochar and the formation of mineral nanostructures. Quantitative (13)C nuclear magnetic resonance (NMR) spectroscopy shows that the presence of the iron clay prevents degradation of the cellulosic fraction at pyrolysis temperatures of 250 °C, whereas at higher temperatures (350-550 °C), the clay promotes biomass degradation, resulting in an increase in both the concentrations of condensed aromatic, acidic, and phenolic carbon species. The porosity of the biochar, as measured by NMR cryoporosimetry, is altered by the iron-clay pretreatment. In the presence of the clay, at lower pyrolysis temperatures, the biochar develops a higher pore volume, while at higher temperature, the presence of clay causes a reduction in the biochar pore volume. The most dramatic reduction in pore volume is observed in the kaolinite-infiltrated biochar at 550 °C, which is attributed to the blocking of the mesopores (2-50 nm pore) by the nonporous metakaolinite formed from kaolinite.
Publisher: Springer Science and Business Media LLC
Date: 02-1988
DOI: 10.1007/BF03258828
Publisher: Springer Science and Business Media LLC
Date: 03-03-2012
Publisher: Springer Science and Business Media LLC
Date: 07-02-2017
Publisher: Elsevier BV
Date: 04-2001
Publisher: Springer Science and Business Media LLC
Date: 14-07-2015
Publisher: Elsevier BV
Date: 05-2017
Publisher: Elsevier BV
Date: 06-2020
Publisher: Informa UK Limited
Date: 11-10-2004
Publisher: Elsevier BV
Date: 03-2021
Publisher: IOP Publishing
Date: 08-2009
Publisher: Wiley
Date: 20-04-2015
Publisher: Elsevier BV
Date: 10-2014
Publisher: American Physical Society (APS)
Date: 22-09-2009
Publisher: Elsevier BV
Date: 10-2015
Publisher: AIP Publishing
Date: 21-01-2002
DOI: 10.1063/1.1436280
Abstract: The mechanical deformation of wurtzite GaN epilayers grown on sapphire substrates is studied by spherical indentation, cross-sectional transmission electron microscopy (XTEM), and scanning cathodoluminescence (CL) monochromatic imaging. CL imaging of indents which exhibit plastic deformation (based on indentation data) shows an observable “footprint” of deformation-produced defects that result in a strong reduction in the intensity of CL emission. Multiple discontinuities are observed during loading when the maximum load is above the elastic-plastic threshold, and such a behavior can be correlated with multiple slip bands revealed by XTEM. No evidence of pressure-induced phase transformations is found from within the mechanically damaged regions using selected-area diffraction patterns. The main deformation mechanism appears to be the nucleation of slip on the basal planes, with dislocations being nucleated on additional planes on further loading. XTEM reveals no cracking or delamination in any of the s les studied for loads of up to 250 mN.
Publisher: IOP Publishing
Date: 12-10-2015
Publisher: Elsevier BV
Date: 07-2009
Publisher: Elsevier BV
Date: 12-2014
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 06-2016
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/SR10012
Abstract: Amazonian Dark Earths (Terra Preta) are anthropogenic soils with high organic carbon content and the ability to sustain higher fertility than adjacent, intensely weathered, acidic soils. Consequently, the microstructural development of biochar–mineral complexes, termed synthetic Terra Preta (STP), has been investigated. Here, biochar–mineral complexes are produced at elevated temperatures to mimic the structure of Terra Preta. These materials, if added to soils, may then also improve fertility. The raw materials used in STP were organic biowaste, such as sawdust, chicken manure, and blood and bone, and inorganic minerals such as kaolinite, bentonite, and cement kiln dust (which consists mainly of calcite). The STP s les were characterised using X-ray photoelectron spectroscopy, nuclear magnetic resonance, scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and associated microchemical analytical methods, to gain an understanding of the interactions that occurred during processing between the organic and inorganic phases. The STP specimens exhibited microstructures that closely resemble Terra Preta. SEM and TEM revealed a complex aggregation of phases, together with evidence of the interfacial reactions, especially at higher processing temperatures. It is anticipated then that STP may be as effective in promoting plant growth and in sequestering carbon as Terra Preta
Publisher: Trans Tech Publications, Ltd.
Date: 15-11-2016
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.879.350
Abstract: In this study the effects of heating rate on the sharpness and size of Goss oriented ({110} ) grains during secondary recrystallization annealing at 900 °C was observed. The results show that, at the same annealing temperature, rapid heating of the s les to this temperature generates a higher drag force compared to a slower heating rate (5°C/min). The two groups of s les show different growth kinetics for Goss grains, in which at the longest annealing time, the rapid heating s le exhibits larger maximum Goss grain size compared to the slower heated s les.
Publisher: AIP Publishing
Date: 10-04-2002
DOI: 10.1063/1.1469660
Abstract: The deformation mechanisms of crystalline (100) Ge were studied using nanoindentation, cross sectional transmission electron microscopy (XTEM) and Raman microspectroscopy. For a wide range of indentation conditions using both spherical and pointed indenters, multiple discontinuities were found in the force–displacement curves on loading, but no discontinuities were found on unloading. Raman microspectroscopy, measured from s les which had plastically deformed on loading, showed a spectrum shift from that in pristine Ge, suggesting only residual strain. No evidence (such as extra Raman bands) was found to suggest that any pressure-induced phase transformations had occurred, despite the fact that the material had undergone severe plastic deformation. Selected area diffraction pattern studies of the mechanically damaged regions also confirmed the absence of additional phases. Moreover, XTEM showed that, at low loads, plastic deformation occurs by twinning and dislocation motion. This indicates that the hardness of Ge measured by indentation is not primarily dominated by phase transformation, rather by the nucleation and propagation of twin bands and/or dislocations.
Publisher: Springer Science and Business Media LLC
Date: 2001
Publisher: Informa UK Limited
Date: 11-1995
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.SCITOTENV.2019.136431
Abstract: Biochar-based compound fertilizers (BCF) and amendments have proven to enhance crop yields and modify soil properties (pH, nutrients, organic matter, structure etc.) and are now in commercial production in China. While there is a good understanding of the changes in soil properties following biochar addition, the interactions within the rhizosphere remain largely unstudied, with benefits to yield observed beyond the changes in soil properties alone. We investigated the rhizosphere interactions following the addition of an activated wheat straw BCF at an application rates of 0.25% (g·g
Publisher: Elsevier BV
Date: 10-2015
Publisher: Springer Science and Business Media LLC
Date: 03-2012
DOI: 10.1557/MRC.2011.24
Publisher: Elsevier BV
Date: 02-2014
Publisher: Springer Science and Business Media LLC
Date: 18-11-2009
Publisher: Elsevier BV
Date: 1994
Publisher: Elsevier BV
Date: 09-2012
Publisher: Springer Science and Business Media LLC
Date: 07-2021
Publisher: Elsevier BV
Date: 05-2013
Publisher: Informa UK Limited
Date: 07-1995
Publisher: Elsevier BV
Date: 05-1991
Publisher: Springer Science and Business Media LLC
Date: 24-11-2011
DOI: 10.1557/JMR.2011.367
Publisher: Elsevier BV
Date: 10-2014
Publisher: Informa UK Limited
Date: 11-2012
Publisher: Royal Society of Chemistry (RSC)
Date: 26-06-2014
DOI: 10.1039/C4TA01888E
Publisher: Informa UK Limited
Date: 20-10-2021
Publisher: Wiley
Date: 04-04-2017
Abstract: As a new family member of room-temperature aprotic metal-O
Publisher: Elsevier BV
Date: 07-2003
Publisher: Elsevier BV
Date: 2008
Publisher: Elsevier BV
Date: 05-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3RA22425B
Publisher: Elsevier BV
Date: 02-2007
Publisher: Elsevier BV
Date: 12-2007
Publisher: Elsevier BV
Date: 08-2011
Publisher: Wiley
Date: 26-09-2011
DOI: 10.1111/J.1365-2818.2011.03553.X
Abstract: Black carbon (BC) is one of the most stable forms of soil organic matter. Its surface functional groups and structure have been well characterized by a range of analytical methods. However, little is known about the mechanisms of interactions between the BC particles and the surrounding mineral matter. In this paper a range of microscopy techniques, such as transmission electron microscopy and scanning transmission electron microscopy, were used to investigate the possible reactions of BC particles within microaggregates (<2 mm) found in Amazonian dark Earth. Attention is given to the interactions that occur at the interfacial regions between the organic and inorganic phases. Examination of Amazonian dark Earth showed that the carbon-rich phase detected within the BC particles has a significant calcium concentration and a high density of micropores was found at the BC-mineral interface. These observations provide evidence to support suggested mechanisms of interaction between these phases.
Publisher: Springer Science and Business Media LLC
Date: 2002
Publisher: Elsevier BV
Date: 04-1994
Publisher: Elsevier BV
Date: 05-2007
Publisher: IOP Publishing
Date: 18-10-2002
Publisher: American Chemical Society (ACS)
Date: 03-05-2022
Publisher: Springer Science and Business Media LLC
Date: 1991
DOI: 10.1007/BF00543642
Publisher: Elsevier BV
Date: 2017
Publisher: Elsevier BV
Date: 07-2019
Publisher: Elsevier BV
Date: 02-2008
Publisher: Elsevier BV
Date: 04-2002
Publisher: AIP Publishing
Date: 07-2006
DOI: 10.1063/1.2210767
Abstract: The deformation behavior of ion-implanted (unrelaxed) and annealed ion-implanted (relaxed) amorphous silicon (a-Si) under spherical indentation at room temperature has been investigated. It has been found that the mode of deformation depends critically on both the preparation of the amorphous film and the scale of the mechanical deformation. Ex situ measurements, such as Raman microspectroscopy and cross-sectional transmission electron microscopy, as well as in situ electrical measurements reveal the occurrence of phase transformations in all relaxed a-Si films. The preferred deformation mode of unrelaxed a-Si is plastic flow, only under certain high load conditions can this state of a-Si be forced to transform. In situ electrical measurements have revealed more detail of the transformation process during both loading and unloading. We have used ELASTICA simulations to obtain estimates of the depth of the metallic phase as a function of load, and good agreement is found with the experiment. On unloading, a clear change in electrical conductivity is observed to correlate with a “pop-out” event on load versus penetration curves.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Informa UK Limited
Date: 2005
DOI: 10.1179/MHT.2005.041
Publisher: Elsevier BV
Date: 08-2013
Publisher: Oxford University Press (OUP)
Date: 07-2009
DOI: 10.1017/S1431927609093349
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009
Publisher: Springer Science and Business Media LLC
Date: 08-2007
Abstract: Monolithic TiN and multilayered structures of TiN films that alternate with thin Ti interlayers were coated by filtered arc deposition onto a stainless steel substrate. Microscratch tests with a diamond indenter of 5-μm radius were carried out in combination with focused ion beam (FIB) sectioning and scanning and transmission electron microscopy to explore the controlling deformation mechanisms of these TiN coatings in relation to their microstructural design. It was found that for the monolithic TiN coating, columnar TiN grains slid against each other under normal forces and, at the same time, tilted under tangential forces. For the TiN multilayers, however, intercolumnar shear sliding was suppressed considerably by the multilayered structure and the interlayers, and grain tilting occurred largely within the upper TiN layer, presumably due to the shear effect of the soft Ti interlayers. With further increases in tangential force, rupture of TiN grains was observed within both types of coatings for the TiN multilayers, rupture of TiN grains occurred predominantly within the layers close to the steel substrates. It can be concluded that the application of TiN multilayers provides better resistance to contact damage than the traditional monolithic TiN coatings did.
Publisher: Elsevier BV
Date: 08-2010
Publisher: Elsevier BV
Date: 11-2022
Publisher: AIP Publishing
Date: 07-03-2008
DOI: 10.1063/1.2837246
Abstract: We report for the first time the Al and C codoping effect on the structures and superconductivity in MgB2. It was found that both the lattice parameters and the Tc decreased monotonically with increasing doping level of both Al and C. The Tc dropped to 27.5 and 7K for x=0.2 and for x=0.4, respectively. The reduction of Tc for the codoping was found to be quicker than for in idual Al doping and slower than for in idual C doping at the same doping levels. First-principles calculations indicated that the observed decrease in Tc for the codoped MgB2 can be understood in terms of a band filling effect due to the electron doping by both Al and C. However, it is suggested that other factors may also play a role in the Tc reduction in the real Mg1−xAlxB2−xCx s les. Furthermore, the Al and C codoping also reduces Jc and weakens flux pinning in MgB2.
Publisher: Springer Science and Business Media LLC
Date: 13-06-2012
Publisher: Elsevier BV
Date: 06-2014
Publisher: Springer Science and Business Media LLC
Date: 25-05-2016
Publisher: Springer Science and Business Media LLC
Date: 05-2007
DOI: 10.1557/MRS2007.64
Abstract: This article reviews recent developments and applications of focused ion beam (FIB) microscopes for three-dimensional (3D) materials characterization at the microscale through destructive serial sectioning experiments. Precise ion milling—in combination with electron-optic—based imaging and surface analysis methods—can be used to iteratively section through metals, ceramics, polymers, and electronic or biological materials to reveal the true size, shape, and distribution of microstructural features. Importantly, FIB tomographic experiments cover a critical size-scale gap that cannot be obtained with other instrumentation. The experiments encompass material volumes that are typically larger than 1000 μm 3 , with voxel dimensions approaching tens of nanometers, and can contain structural, chemical, and crystallographic information. This article describes the current state of the art of this experimental methodology and provides ex les of specific applications to 3D materials characterization.
Publisher: Elsevier BV
Date: 05-1995
Publisher: Springer Science and Business Media LLC
Date: 09-06-2010
Publisher: Elsevier BV
Date: 08-2018
Publisher: Wiley
Date: 06-12-2011
Abstract: Polyhedral magnetite nanocrystals with multiple facets were synthesised by a low temperature hydrothermal method. Atomistic simulation and calculations on surface attachment energy successfully predicted the polyhedral structure of magnetite nanocrystals with multiple facets. X-ray diffraction, field emission scanning electron microscopy, and high resolution transmission microscopy confirmed the crystal structure of magnetite, which is consistent with the theoretical modelling. The magnetic property measurements show the superspin glass state of the polyhedral nanocrystals, which could originate from the nanometer size of in idual single crystals. When applied as an anode material in lithium ion cells, magnetite nanocrystals demonstrated an outstanding electrochemical performance with a high lithium storage capacity, a satisfactory cyclability, and an excellent high rate capacity.
Publisher: Elsevier BV
Date: 11-1992
Publisher: Elsevier BV
Date: 12-2018
Publisher: American Physical Society (APS)
Date: 13-02-2014
Publisher: Springer Science and Business Media LLC
Date: 28-02-2014
DOI: 10.1038/SREP04239
Publisher: Elsevier BV
Date: 09-2013
Publisher: AIP Publishing
Date: 30-09-2003
DOI: 10.1063/1.1606884
Abstract: MgB 2 -diamond nanocomposite superconductors have been synthesized by addition of nanodiamond powder. Microstructural analysis shows that the nanocomposite superconductor consists of tightly packed MgB2 nanograins (∼50–100 nm) with highly dispersed and uniformly distributed diamond nanoparticles (∼10–20 nm) inside the grains. The Jc–H and Hiir–T characteristics have been significantly improved in this MgB2-diamond nanocomposite, compared to MgB2 bulk materials prepared by other techniques. Also, the Jc value of 1×104 A/cm2 at 20 K and 4 T and the Hirr value of 6.4 T at 20 K have been achieved.
Publisher: Oxford University Press (OUP)
Date: 04-03-2005
DOI: 10.1017/S1431927605050294
Abstract: The damage layers generated in III–V compounds exposed to energetic gallium ions in a focused ion beam (FIB) instrument have been characterized by transmission electron microscopy (TEM). The damage on the side walls of the milled trenches is in the form of amorphous layers associated with direct amorphization from the gallium beam, rather than from redeposition of milled material. However, the damage on the bottom of the milled trenches is more complex. For InP and InAs the damage layers include the presence of crystalline phases resulting from recrystallization associated heating from the incident beam and gallium implantation. In contrast, such crystalline phases are not present in GaAs. The thicknesses of the damage layers are greater than those calculated from theoretical models of ion implantation. These differences arise because the dynamic nature of FIB milling means that the energetic ion beams pass through already damaged layers. In InP recoil phosphorus atoms also cause significant damage.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2003
Publisher: Elsevier BV
Date: 11-2015
Publisher: Elsevier BV
Date: 06-2013
Publisher: Elsevier BV
Date: 03-2020
Publisher: IOP Publishing
Date: 30-10-2008
DOI: 10.1088/0957-4484/19/47/475709
Abstract: We investigate the mechanical response of 50-600 nm epitaxial Ge films on a Si substrate using nanoindentation with a nominally spherical (R≈4.3 µm) diamond tip. The inelastic deformation mechanism is found to depend critically on the film thickness. Sub-100 nm Ge films deform by pressure-induced phase transformation, whereas thicker films deform only by shear-induced dislocation slip and twinning. Nanoindentation fracture response is similarly dependent on film thickness. Elastic stress modelling shows that differing stress modes vary in their spatial distribution, and consequently the film thickness governs the stress state in the film, in conjunction with the radius of the nanoindenter tip. This opens the prospect of tailoring the contact response of Ge and related materials in thin film form by varying film thickness and indenter radius.
Publisher: Springer Science and Business Media LLC
Date: 02-2010
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 05-2018
Publisher: Springer Science and Business Media LLC
Date: 29-07-2020
Publisher: Elsevier BV
Date: 2017
Publisher: Elsevier BV
Date: 04-2018
Publisher: Springer Science and Business Media LLC
Date: 2012
Abstract: The pin-on-disc wear behavior of nanostructured two-phase Fe 30 Ni 20 Mn 20 Al 30 and eutectic lamellar-structured Fe 30 Ni 20 Mn 35 Al 15 is compared emphasizing the influence of the microstructure and mechanical properties of alloys as well as the effect of test environment. Although the wear of both alloys was greater in oxygen-containing environments, eutectic Fe 30 Ni 20 Mn 35 Al 15 is less sensitive to oxygen than nanostructured Fe 30 Ni 20 Mn 20 Al 30 . Abrasive wear dominated during the wear in all cases, while plastic deformation also occurred during the wear of eutectic Fe 30 Ni 20 Mn 35 Al 15 . A tribolayer of zirconia, which was embedded in the surface of the wear pin, was characterized using a scanning transmission electron microscope equipped with an energy dispersive spectrometer.
Publisher: World Scientific Pub Co Pte Lt
Date: 20-01-2010
DOI: 10.1142/S0217979210063934
Abstract: The deformation microstructures generated by nanoindentation of multilayer coatings consisting of TiSiN layers alternating with ten TiN interlayers, were examined by cross-sectional transmission electron microscopy (XTEM). Two multilayered coatings were studied: a thin TiSiN coating interlayered with thick TiN interlayer and a thick TiSiN coating alternated with thin TiN layers. A monolithic TiSiN coating was also examined for comparison. Surface morphology of the s les was found to be variable. Both surface roughness and coating hardness increase with the thickness of the outermost TiSiN layer. All s les show columnar structures, and for the multilayer coatings, epitaxial growth of these columnar grains through the TiSiN / TiN multilayers was observed. Stair-shaped shear cracks can be seen in the multilayer coating alternated with thick TiN interlayers, whereas radial and edge cracks are observed in the coating multilayered with thin TiN layers and in the monolithic coating. TEM analysis also suggests that columnar grains help to resist the initiation of edge cracks. Compared to other studies on similar coating systems with fewer periods of interlayers, the deformation observed here appears less severe, indicating an improvement in the strength of the coating through increasing the number of interlayers.
Publisher: Elsevier BV
Date: 05-2022
Publisher: Elsevier BV
Date: 12-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA09733A
Abstract: A ZrN coating with an average grain size of ∼15 nm, was employed to improve the surface performance and durability of 316L stainless steel (SS) used in polymer electrolyte membrane fuel cells (PEMFCs) environments.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NR03289E
Abstract: Due to the operation of unconventional toughening mechanisms, including amorphization and multiple shear banding, the medium-entropy nitride, CrCoNiN doped with Al and Ti, exhibits a superior combination of hardness and fracture toughness.
Publisher: Springer Science and Business Media LLC
Date: 10-2006
Abstract: An amorphous carbon coating, approximately 1.7 μm thick, deposited onto a ductile steel substrate, was indented using a 5-μm radius spherical-tipped diamond indenter to a maximum load of 150 mN. Displacement discontinuities were observed during loading, indicative of crack formation in the system. After indentation, a focused ion beam instrument was used to prepare cross-sections, which revealed the presence of ring, radial, and lateral cracks. A three-dimensional reconstruction of the deformation zone beneath the indent was conducted using a dual ion/electron beam instrument, assisted by a commercial three-dimensional visualization software package. These three-dimensional images enabled a detailed analysis of indentation-induced cracking in this film at submicron resolution. In contrast to traditional understanding and modeling, it was observed that the development of ring cracks was asymmetric for this type of coating/substrate system. Based on this observation, it can be deduced that the strain energy release rate was different for the growth of the spiral ring crack compared with the traditional concentric-ring model. Consequently, the concentric ring-crack fracture model may not be appropriate for the evaluation of the fracture toughness of this type of coating. Hence, three-dimensional images have presented a requirement that the asymmetrical nature of ring and radial cracks should be addressed and carefully considered in the fracture mechanics analysis of this type of hard coating system.
Publisher: AIP Publishing
Date: 06-02-2008
DOI: 10.1063/1.2830830
Abstract: Synthesis and characterization of Fe and rare earth (RE) (RE=Eu,Nd) codoped bulk In2O3 oxide are reported. Composites consisting of Fe-doped In2O3 and InREO3 phases were formed, as determined by x-ray diffraction and transmission electron microscopy, with particle sizes of 50–120nm. The composites exhibit superparamagnetic and semiconducting behavior. A giant positive magnetoresistance is observed at low temperatures, reaching 81% and 50% at 5K in Eu–Fe and Nd–Fe codoped s les, respectively.
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 02-2021
Publisher: Wiley
Date: 28-05-2021
Abstract: Hard carbons with low cost and high specific capacity hold great potential as anode materials for potassium‐based energy storage. However, their sluggish reaction kinetics and inevitable volume expansion degrade their electrochemical performance. Through rational nanostructure design and a heteroatom doping strategy, herein, the synthesis of phosphorus/oxygen dual‐doped porous carbon spheres is reported, which possess expanded interlayer distances, abundant redox active sites, and oxygen‐rich defects. The as‐developed battery‐type anode material shows high discharge capacity (401 mAh g −1 at 0.1 A g −1 ), outstanding rate capability, and ultralong cycling stability (89.8% after 10 000 cycles). In situ Raman spectroscopy and density functional theory calculations further confirm that the formation of PC and PO/POH bonds not only improves structural stability, but also contributes to a rapid surface‐controlled potassium adsorption process. As a proof of concept, a potassium‐ion hybrid capacitor is assembled by a dual‐doped porous carbon sphere anode and an activated carbon cathode. It shows superior electrochemical performance, which opens a new avenue to innovative potassium‐based energy storage technology.
Publisher: Springer Science and Business Media LLC
Date: 28-08-2012
Publisher: Elsevier BV
Date: 2020
Publisher: Springer Science and Business Media LLC
Date: 06-10-2014
DOI: 10.1038/SREP06519
Publisher: Springer Science and Business Media LLC
Date: 12-2021
Publisher: Elsevier BV
Date: 04-1994
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5TB00236B
Abstract: The study aims to advance the applicability of titanium alloys as bone implant materials by tackling some important aspects of surface robustness and bioactivity.
Publisher: IOP Publishing
Date: 10-01-2013
Publisher: Elsevier BV
Date: 2011
Publisher: Informa UK Limited
Date: 06-2013
DOI: 10.4155/CMT.13.23
Publisher: Elsevier BV
Date: 02-2020
Publisher: Oxford University Press (OUP)
Date: 07-2012
DOI: 10.1017/S1431927612004990
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2009
Publisher: Elsevier BV
Date: 03-2019
Publisher: Elsevier BV
Date: 09-2012
Publisher: Elsevier BV
Date: 03-2005
Publisher: Elsevier BV
Date: 2023
Publisher: Springer Science and Business Media LLC
Date: 30-11-2015
DOI: 10.1038/SREP16773
Abstract: Agricultural soils are the primary anthropogenic source of atmospheric nitrous oxide (N 2 O), contributing to global warming and depletion of stratospheric ozone. Biochar addition has shown potential to lower soil N 2 O emission, with the mechanisms remaining unclear. We incubated eucalypt biochar (550 °C) – 0, 1 and 5% (w/w) in Ferralsol at 3 water regimes (12, 39 and 54% WFPS) – in a soil column, following gamma irradiation. After N 2 O was injected at the base of the soil column, in the 0% biochar control 100% of expected injected N 2 O was released into headspace, declining to 67% in the 5% amendment. In a 100% biochar column at 6% WFPS, only 16% of the expected N 2 O was observed. X-ray photoelectron spectroscopy identified changes in surface functional groups suggesting interactions between N 2 O and the biochar surfaces. We have shown increases in -O-C = N yridine pyrrole/NH 3 , suggesting reactions between N 2 O and the carbon (C) matrix upon exposure to N 2 O. With increasing rates of biochar application, higher pH adjusted redox potentials were observed at the lower water contents. Evidence suggests that biochar has taken part in redox reactions reducing N 2 O to dinitrogen (N 2 ), in addition to adsorption of N 2 O.
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.SCITOTENV.2017.06.186
Abstract: Recent studies have shown that the pyrolysis of biomass combined with clay can result in both lower cost and increase in plant yields. One of the major sources of nutrients for pasture growth, as well as fuel and building materials in Tibet is yak dung. This paper reports on the initial field testing in a pasture setting in Tibet using yak dung, biochar, and attapulgite clay/yak dung biochars produced at ratios of 10/90 and 50/50 clay to dung. We found that the treatment with attapulgite clay/yak dung (50/50) biochar resulted in the highest pasture yields and grass nutrition quality. We also measured the properties and yields of mixtures of clay/yak dung biochar used in the field trials produced at 400°C and 500°C to help determine a possible optimum final pyrolysis temperature and dung/clay ratio. It was observed that increasing clay content increased carbon stability, overall biochar yield, pore size, carboxyl and ketone/aldehyde functional groups, hematite and ferrous/ferric sulphate/thiosulphate concentration, surface area and magnetic moment. Decreasing clay content resulted in higher pH, CEC, N content and an enhanced ability to accept and donate electrons. The resulting properties were a complex function of both processing temperature and the percentage of clay for the biochars processed at both 400°C and 500°C. It is possible that the increase in yield and nutrient uptake in the field trial is related to the higher concentration of C/O functional groups, higher surface area and pore volume and higher content of Fe/O/S nanoparticles of multiple oxidation state in the 50/50 clay/dung. These properties have been found to significantly increase the abundance of beneficial microorganisms and hence improve the nutrient cycling and availability in soil. Further field trials are required to determine the optimum pyrolysis production conditions and application rate on the abundance of beneficial microorganisms, yields and nutrient quality.
Publisher: Elsevier BV
Date: 02-2007
Publisher: Elsevier BV
Date: 06-2004
Publisher: Elsevier BV
Date: 10-2016
Publisher: Elsevier BV
Date: 06-2022
Publisher: Elsevier BV
Date: 1996
Publisher: Springer Science and Business Media LLC
Date: 26-04-2008
DOI: 10.1007/S10856-008-3441-2
Abstract: Molar-incisor-hypomineralisation (MIH), one of the major developmental defects in dental enamel, is presenting challenge to clinicians due, in part, to the limited understanding of microstructural changes in affected teeth. Difficulties in the preparation of site-specific transmission electron microscope (TEM) specimens are partly responsible for this deficit. In this study, a dual-beam field emission scanning electron microscope (FESEM)/focused ion beam (FIB) milling instrument was used to prepare electron transparent specimens of sound and hypomineralised enamel. Microstructural analysis revealed that the hypomineralised areas in enamel were associated with marked changes in microstructure loosely packed apatite crystals within prisms and wider sheath regions were identified. Microstructural changes appear to occur during enamel maturation and may be responsible for the dramatic reduction in mechanical properties of the affected regions. An enhanced knowledge of the degradation of structural integrity in hypomineralised enamel could shed light on more appropriate management strategies for these developmental defects.
Publisher: Springer Science and Business Media LLC
Date: 12-05-2021
DOI: 10.1186/S40538-021-00222-X
Abstract: Fostering plant growth and improving agricultural yields by adding “macro”-sized biochar to soil has been extensively explored. However, the impact and mechanism of action of aqueous extracts of biochar applied as foliar fertilizer on plant growth and physiology is poorly understood, and was the objective of this study. Extracts were produced from biochars derived from pine wood:clay:sand (PCS-BC 70:15:15) and wheat straw:bird manure (WB-BC 50:50) and tested at two dilutions each. The plant influence of the biochar extracts and dilutions were compared with chemical fertilizer made up to the same minor trace element compositions as the applied extracts and a control treatment consisting of only deionized water. The WB-BC extract was more alkaline than the PCS-BC extract and exhibited higher electrical conductivity values. Similar to the biochars from which they were derived, the WB-BC extract had higher concentrations of dissolved mineral elements and organic matter than the PCS-BC extract. Despite major differences in chemical composition between the PCS-BC and WB-BC extracts, there was virtually no difference in plant performance between them at any chosen dilution. Foliar application of PCS25, WB50, and WB100 led to a significant increase in the plant fresh biomass in comparison to their corresponding chemical fertilizer and to deionized water. Plant growth parameters including number of leaves and chlorophyll contents in plants treated with biochar extract foliar sprays were significantly higher than in all the other treatments. Electron microscopy and spectroscopy studies showed the deposition of macro- and nanoscale organomineral particles and agglomerates on leaf surfaces of the examined PCS25-treated plant. Detailed study suggests that carbon nanomaterials and TiO 2 or Si-rich nanoscale organomineral complexes or aluminosilicate compounds from biochar extract were main contributors to increased plant growth and improved plant performance. These results suggest that biochar extracts have the potential to be used as nanofertilizer foliar sprays for enhancing plant growth and yield.
Publisher: Springer Science and Business Media LLC
Date: 22-07-2013
DOI: 10.1038/SREP02247
Publisher: Elsevier BV
Date: 02-2013
Publisher: Elsevier BV
Date: 1996
Publisher: IOP Publishing
Date: 26-04-2006
Publisher: Elsevier BV
Date: 10-2017
Publisher: AIP Publishing
Date: 15-09-2007
DOI: 10.1063/1.2781394
Abstract: Nanoindentation-induced formation of high pressure crystalline phases (Si-III and Si-XII) during unloading has been studied by Raman micro-spectroscopy, cross-sectional transmission electron microscopy (XTEM), and postindentation electrical measurements. For indentation in crystalline silicon (c-Si), rapid unloading (∼1000 mN∕s) results in the formation of amorphous silicon (a-Si) only a result we have exploited to quench the formation of high pressure phases at various stages during unloading to study their formation and evolution. This reveals that seed volumes of Si-III and Si-XII form during the early stages of unloading with substantial volumes only forming after the pop-out event that occurs at about 50% of the maximum load. In contrast, high pressure phases form much more readily in an a-Si matrix, with substantial volumes forming without an observable pop-out event with rapid unloading. Postindentation electrical measurements have been used to further investigate the end phases and to identify differences between indentations which otherwise appear to be identical from the XTEM and Raman analyses.
Publisher: Elsevier BV
Date: 12-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 1990
DOI: 10.1109/33.58865
Publisher: Elsevier BV
Date: 04-2012
DOI: 10.1016/J.CHEMOSPHERE.2011.12.007
Abstract: Biochar, as a soil amendment, can increase concentrations of soil organic matter, especially water-extractable organic carbon (WEOC). This can affect the adsorption-desorption equilibrium between the dissolved solid phases in soil organic matter. Dissolved organic carbon (DOC) represents a small proportion of soil organic matter, but is of significant importance in the soil ecosystem due to its mobility and reactivity. Here, water extracts obtained from twelve non-herbaceous biochars (before, and after, chemical treatment with either H(3)PO(4) or KOH), were tested by Liquid Chromatography - Organic Carbon Detection (LC-OCD) to identify the effects of both pyrolysis conditions and chemical treatments on WEOC content. LC-OCD has the capacity to provide a fingerprint of WEOC, which allows analysis of the various fractions present. WEOC content was affected by both the pyrolysis temperature and the feedstock used. High mineral ash contents deriving from the feedstock can prompt thermochemical reactions of lignocelluloses to produce a relatively high WEOC content, which includes low molecular weight neutrals and humic acids as dominant components. A significant change in WEOC occurred during pyrolysis due to secondary reactions which resulted in a much lower WEOC in the high temperature biochars where fractions of low molecular weight acids and neutrals are dominant. Chemical treatments with H(3)PO(4) or KOH increased WEOC concentration, possibly by promoting hydrolysis reactions on biochar surfaces. These observations assist in assessing the contribution of biochar additions to the soil ecosystem and demonstrate the utility of LC-OCD in providing an understanding of how biochar additions to soil can alter DOC.
Publisher: Elsevier BV
Date: 09-2014
Publisher: Elsevier BV
Date: 10-2022
Publisher: Springer Science and Business Media LLC
Date: 05-1991
Abstract: Ternary sublattice site occupancy in two L1 2 -structured intermetallic compounds were evaluated by a transmission electron microscope technique called ALCHEMI, or atom site location by channeling enhanced microanalysis, and by x-ray diffractometry, through measuring the relative integrated intensity of fundamental and superlattice x-ray diffraction peaks. The x-ray diffractometry showed that in nickel-rich Ni 3 Al + Hf hafnium was found to occupy preferentially the aluminum sublattice, and in a multiphase alloy an L1 2 -structured phase with the composition Al 74.2 Ti 19 Ni 6.8 nickel atoms showed a strong preference for the titanium sublattice. The ALCHEMI data broadly agreed with the x-ray results for Ni 3 Al but gave completely the opposite result, i.e., a preference of nickel for the titanium sublattice, for Al 3 Ti. The methods of ALCHEMI and x-ray diffractometry are compared, and it is concluded that ALCHEMI data may be easily convoluted by peak overlap and delocalization effects.
Publisher: Elsevier BV
Date: 02-2003
DOI: 10.1016/S0968-4328(03)00007-6
Abstract: Artifacts associated with transmission electron microscope (TEM) specimens prepared using a focused ion beam (FIB) are not well understood, especially those in non-semiconductor materials. In this paper the extent and origins of artifacts associated with redeposition of milled material in TEM specimens of a FeAl--WC metal matrix composite prepared by FIB were investigated. Cross-sections were prepared normal to an initial FIB cut that allowed direct observation of any damage layers, which are believed to be associated with both redeposition of sputtered material and amorphisation of the surface of the specimen by the ion beam. Techniques for the minimisation of redeposition using either final cleaning mills at low accelerating voltages or plasma cleaning were also investigated and found to be ineffective in removing or reducing these damaged layers. TEM cross-sections of specimens treated using low energy mills and plasma cleaning, further confirmed that these techniques did little to reduce any redeposited or amorphous material.
Publisher: Elsevier BV
Date: 06-2008
DOI: 10.1016/J.BIOMATERIALS.2008.02.022
Abstract: Tooth enamel is the hardest tissue in the human body with a complex hierarchical structure. Enamel hypomineralisation--a developmental defect--has been reported to cause a marked reduction in the mechanical properties of enamel and loss of dental function. We discover a distinctive difference in the inelastic deformation mechanism between sound and hypomineralised enamels that is apparently controlled by microstructural variation. For sound enamel, when subjected to mechanical forces the controlling deformation mechanism was distributed shearing within nanometre thick protein layer between its constituent mineral crystals whereas for hypomineralised enamel microcracking and subsequent crack growth were more evident in its less densely packed microstructure. We develop a mechanical model that not only identifies the critical parameters, i.e., the thickness and shear properties of enamels, that regulate the mechanical behaviour of enamel, but also explains the degradation of hypomineralised enamel as manifested by its lower resistance to deformation and propensity for catastrophic failure. With support of experimental data, we conclude that for sound enamel an optimal microstructure has been developed that endows enamel with remarkable structural integrity for durable mechanical function.
Publisher: Oxford University Press (OUP)
Date: 07-2012
DOI: 10.1017/S143192761200966X
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.
Publisher: MDPI AG
Date: 26-05-2016
DOI: 10.3390/MET6060127
Publisher: Elsevier BV
Date: 05-1993
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 11-2017
Publisher: Elsevier BV
Date: 02-2021
Publisher: Springer Science and Business Media LLC
Date: 21-11-2020
Publisher: American Chemical Society (ACS)
Date: 12-09-2011
DOI: 10.1021/JP204091E
Publisher: Springer Science and Business Media LLC
Date: 1996
DOI: 10.1007/BF01159304
Publisher: Elsevier BV
Date: 09-1993
Publisher: Informa UK Limited
Date: 03-2013
Publisher: Elsevier BV
Date: 03-2017
Publisher: Elsevier BV
Date: 10-2015
Publisher: Elsevier BV
Date: 04-1989
Publisher: Elsevier BV
Date: 1995
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 02-1995
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2005
Publisher: Springer Science and Business Media LLC
Date: 27-12-2017
Publisher: Elsevier BV
Date: 12-1997
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 07-2019
Publisher: Wiley
Date: 20-06-2013
Publisher: Elsevier BV
Date: 03-2016
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 10-2004
Publisher: Elsevier BV
Date: 11-2014
Publisher: American Physical Society (APS)
Date: 23-04-2009
Publisher: Springer Science and Business Media LLC
Date: 02-1996
DOI: 10.1007/BF00367878
Publisher: Iron and Steel Institute of Japan
Date: 2017
Publisher: Elsevier BV
Date: 07-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2003
Publisher: IOP Publishing
Date: 17-01-2006
Publisher: AIP Publishing
Date: 10-06-2002
DOI: 10.1063/1.1486264
Abstract: Contact-induced damage has been studied in single-crystal (wurtzite) ZnO by cross-sectional transmission electron microscopy (XTEM) and scanning cathodoluminescence (CL) monochromatic imaging. XTEM reveals that the prime deformation mechanism in ZnO is the nucleation of slip on both the basal and pyramidal planes. Some indication of dislocation pinning was observed on the basal slip planes. No evidence of either a phase transformation or cracking was observed by XTEM in s les loaded up to 50 mN with an ∼4.2 μm radius spherical indenter. CL imaging reveals a quenching of near-gap emission by deformation-produced defects. Both XTEM and CL show that this comparatively soft material exhibits extensive deformation damage and that defects can propagate well beyond the deformed volume under contact. Results of this study have significant implications for the extent of contact-induced damage during fabrication of ZnO-based (opto)electronic devices.
Publisher: American Chemical Society (ACS)
Date: 22-01-2009
DOI: 10.1021/CM8025329
Publisher: IEEE
Date: 02-2008
Publisher: Elsevier BV
Date: 02-2010
Publisher: Elsevier BV
Date: 02-2007
DOI: 10.1016/J.MICRON.2006.07.010
Abstract: Theory describing a super-resolution microscopy experiment using temporally and spatially coherent structured illumination was developed, and used to derive a method for processing experimental data. Numerical simulations were performed to verify that the method can, in principle, produce super-resolved images that are exactly equivalent to an image processed by a system with a much larger aperture (that is, the correct weighting between different regions of the image spectrum is maintained). The process was then demonstrated experimentally, showing a factor of two improvement in resolution over a diffraction-limited, coherently illuminated, microscope.
Publisher: Elsevier BV
Date: 04-2003
Publisher: Springer Science and Business Media LLC
Date: 2003
Publisher: AIP Publishing
Date: 16-04-2014
DOI: 10.1063/1.4871190
Abstract: Nanoindentation-induced phase transformations have been studied in amorphous Ge thin films. These films initially tend to deform via plastic flow of the amorphous phase under load but at a critical pressure a sudden phase transformation occurs. This transformation, to a soft metallic (β-Sn-like)-Ge phase confined under the indenter, is signified by a “pop-in” event on loading. Following “pop-in,” the indentation tests fall into two distinct types of behavior. In one case, the rate of deformation with increasing load after “pop-in” increases, and the observed end-phase following complete unloading is observed to be predominately diamond-cubic Ge. In the other case, the deformation rate (slope of the loading curve) remains the same as that before “pop-in,” and the end phases following unloading are found to contain predominantly unstable r8 and more stable hexagonal Ge phases. The different transformation pathways for these two cases are shown to be related to the probability that the soft (β-Sn-like)-Ge phase volume, which suddenly forms at the transformation pressure, is either unconstrained by the indenter tip (the first case) or totally constrained under the indenter tip (in the latter case).
Publisher: Informa UK Limited
Date: 03-04-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6RA02550A
Abstract: Transition metal nitride Ti x M 1−x−y N y (M = Al or AlSi) based thin films are evaluated as solar selective surfaces by correlating their spectral selective features with their crystal structure and chemical bonding state including mechanical strength.
Publisher: IOP Publishing
Date: 08-08-2014
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.ACTBIO.2013.09.021
Abstract: In this paper, (Ti1-xNbx)5Si3 nanocrystalline films were synthesized and their potential as highly corrosion-resistant coatings for the biomedical alloy Ti-6Al-4V was explored. To assess the electrochemical behavior of the as-deposited films, the s les were immersed in Ringer's solution open to air at 37°C. The processes that govern the electrochemical reactions at the film surface were analyzed using a combination of complementary electrochemical measurement techniques such as potentiodynamic polarization, electrochemical impedance spectroscopy and Mott-Schottky analysis. The results show that the (Ti1-xNbx)5Si3 nanocrystalline films offer Ti-6Al-4V a strong shield from corrosive attack and the addition of Nb in the films greatly enhances their resistance to corrosion, and in so doing, minimizes metal ion release. Collectively, our data suggest that (Ti1-xNbx)5Si3 nanocrystalline films as supreme coatings with anti-corrosive properties have potential to improve the performance and extend the service life of orthopedic and cochlear implants.
Publisher: Elsevier BV
Date: 05-2004
Publisher: Elsevier BV
Date: 10-2015
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4RA10570B
Abstract: To explore the influence of Al alloying on the oxidation resistance of MoSi 2 , four Mo(Si 1−x Al x ) 2 nanocrystalline films were fabricated on Ti–6A1–4V substrates and their cyclic oxidation behavior was characterized.
Publisher: Elsevier BV
Date: 07-1991
Publisher: Springer Science and Business Media LLC
Date: 08-1992
Abstract: The ternary site occupancy of two alloys, vanadium in NiAl + V and hafnium in nickel-rich, boron doped Ni 3 Al + Hf, was determined by ALCHEMI, or atom location by channeling enhanced microanalysis. Vanadium exhibited a preference for the aluminum sublattice in NiAl, and hafnium preferentially occupied the aluminum sites in Ni 3 Al. Spectra were acquired over a range of accelerating voltages from 80 kV to 200 kV. Delocalization effects were observed to increase as the accelerating voltage increased, which thus reduces the accuracy of the ALCHEMI data. For NiAl + V, both planar and axial channeling were performed, and delocalization effects were greater for axial channeling, further reducing the accuracy of the ALCHEMI data.
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 02-2006
Publisher: Elsevier BV
Date: 08-2003
Publisher: Elsevier BV
Date: 04-2013
Publisher: Elsevier BV
Date: 2023
Publisher: Elsevier BV
Date: 1995
Publisher: Informa UK Limited
Date: 09-1997
Publisher: Elsevier BV
Date: 12-1991
Publisher: AIP Publishing
Date: 07-2005
DOI: 10.1063/1.1992663
Publisher: Springer Science and Business Media LLC
Date: 2003
Abstract: Focused Ion Beam (FIB) systems employ a finely focussed beam of positively charged ions to process materials. Ion induced charging effects in non-conductive materials have been confirmed using Scanning Surface Potential Microscopy (SSPM). Significant localized residual charging is observed within the ion implanted micro-volumes of non-conductive materials both prior to and following the onset of sputtering. Characteristic observed surface potentials associated with the resultant charging have been modelled, giving insight into the charging processes during implantation and sputtering. The results of this work have implications for the processing and microanalysis of non-conductive materials in FIB systems.
Publisher: Springer Science and Business Media LLC
Date: 12-05-2020
Publisher: Wiley
Date: 21-05-2004
Publisher: Elsevier BV
Date: 05-2013
Publisher: Elsevier BV
Date: 02-2020
Publisher: Elsevier BV
Date: 02-2022
Publisher: AIP Publishing
Date: 15-02-2007
DOI: 10.1063/1.2490563
Abstract: Sudden excursions of unusually large magnitude (& μm), “giant pop-ins,” have been observed in the force-displacement curve for high load indentation of crystalline germanium (Ge). A range of techniques including Raman microspectroscopy, focused ion-beam cross sectioning, and transmission electron microscopy, are applied to study this phenomenon. Amorphous material is observed in residual indents following the giant pop-in. The giant pop-in is shown to be a material removal event, triggered by the development of shallow lateral cracks adjacent to the indent. Enhanced depth recovery, or “elbowing,” observed in the force-displacement curve following the giant pop-in is explained in terms of a compliant response of plates of material around the indent detached by lateral cracking. The possible causes of amorphization are discussed, and the implications in light of earlier indentation studies of Ge are considered.
Publisher: Elsevier BV
Date: 11-2006
Publisher: AIP Publishing
Date: 06-12-2004
DOI: 10.1063/1.1832757
Abstract: The deformation behavior of self-ion-implanted amorphous-Si (a-Si) has been studied using spherical nanoindentation in both relaxed (annealed) and unrelaxed (as-implanted) a-Si. Interestingly, phase transformations were clearly observed in the relaxed state, with the load–unload curves from these s les displaying characteristic discontinuities and cross-sectional transmission electron microscopy images indicating the presence of high-pressure crystalline phases Si-III and Si-XII following pressure release. Thus, an amorphous to crystalline phase transformation has been induced by indentation at room temperature. In contrast, no evidence of a phase transformation was observed in unrelaxed a-Si, which appeared to deform via plastic flow of the amorphous phase. Furthermore, in situ electrical measurements clearly indicate the presence of a metallic Si phase during loading of relaxed a-Si but no such behavior was observed for unrelaxed a-Si
Publisher: AIP Publishing
Date: 15-11-2012
DOI: 10.1063/1.4765045
Abstract: Trilayer heterostructures consisting of a ferroelectric bismuth ferrite (BFO) film sandwiched between ferromagnetic lanthanum strontium manganese oxide (LSMO) films were fabricated using pulsed laser deposition. Both BFO thicknesses (20 nm, 5 nm) and cooling rates were varied to investigate the role of processing parameters on the chemistry of the interfaces. The interfaces were investigated using a dedicated aberration corrected scanning transmission electron microscope (STEM) operated at 100 kV via STEM-high angle annular dark field (STEM-HAADF) and STEM-electron energy loss spectroscopy (STEM-EELS) modes. Combined analysis through STEM-HAADF and STEM-EELS revealed the formation of lattice distortion in certain regions of the BFO layer for the ∼5 nm film. Piezoresponse force microscopy (PFM) studies of the ∼5 nm BFO s le revealed weak ferroelectric domain switching. Stacking fault defects with mixed valence manganese (Mn-B site cation) were formed in the top LSMO layer when the heterostructure was cooled at a slower rate irrespective of BFO thickness, thereby demonstrating the effect of processing kinetics on the physical integrity of the heterostructure.
Publisher: Springer Science and Business Media LLC
Date: 2002
Publisher: Elsevier BV
Date: 08-2022
Publisher: Elsevier BV
Date: 2018
Publisher: Wiley
Date: 15-02-2011
Publisher: Elsevier BV
Date: 07-2022
Publisher: Springer Science and Business Media LLC
Date: 02-2006
Abstract: Deformation and fracture of a columnar-grained, ∼1.3-μm-thick TiN coating on a stainless steel substrate was investigated using a spherical tipped conical indenter of 5-μm nominal tip radius. Structural analysis, performed with the support of focused ion beam (FIB) milling and imaging techniques, revealed that the microstructure of the TiN coating had a strong influence on the deformation behavior of the coating. Intergranular sliding in the coating, as well as plastic flow in the ductile substrate, was found to be the predominant processes during the indentation. Neither plastic deformation, in the form of plastic flow, within the coating nor delamination of the interface was observed. Coating deformation was observed to be controlled by the intergranular shear cracking and thus by the interfacial columbic frictional stress between columnar grains. An indentation-energy based model was developed, which deconvolutes the coating behavior from that of the substrate, allowing quantification of the intergranular sliding stress.
Publisher: Wiley
Date: 2003
Publisher: Elsevier BV
Date: 1991
Publisher: CRC Press
Date: 21-02-2013
DOI: 10.1201/B14585
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.JBIOMECH.2013.12.030
Abstract: Human tooth enamel exhibits a unique microstructure able to sustain repeated mechanical loading during dental function. Although notable advances have been made towards understanding the mechanical characteristics of enamel, challenges remain in the testing and interpretation of its mechanical properties. For ex le, enamel was often tested under dry conditions, significantly different from its native environment. In addition, constant load, rather than indentation depth, has been used when mapping the mechanical properties of enamel. In this work, tooth specimens are prepared under hydrated conditions and their stiffnesses are measured by depth control across the thickness of enamel. Crystal arrangement is postulated, among other factors, to be responsible for the size dependent indentation modulus of enamel. Supported by a simple structure model, effective crystal orientation angle is calculated and found to facilitate shear sliding in enamel under mechanical contact. In doing so, the stress build-up is eased and structural integrity is maintained.
Publisher: Elsevier BV
Date: 12-1994
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 07-1994
Publisher: Elsevier BV
Date: 03-2017
Publisher: Elsevier BV
Date: 02-2000
Publisher: AIP Publishing
Date: 04-02-2014
DOI: 10.1063/1.4862556
Abstract: Cation intermixing at functional oxide interfaces remains a highly controversial area directly relevant to interface-driven nanoelectronic device properties. Here, we systematically explore the cation intermixing in epitaxial (001) oriented multiferroic bismuth ferrite (BFO) grown on a (001) lanthanum aluminate (LAO) substrate. Aberration corrected dedicated scanning transmission electron microscopy and electron energy loss spectroscopy reveal that the interface is not chemically sharp, but with an intermixing of ∼2 nm. The driving force for this process is identified as misfit-driven elastic strain. Landau-Ginzburg-Devonshire-based phenomenological theory was combined with the Sheldon and Shenoy formula in order to understand the influence of boundary conditions and depolarizing fields arising from misfit strain between the LAO substrate and BFO film. The theory predicts the presence of a strong potential gradient at the interface, which decays on moving into the bulk of the film. This potential gradient is significant enough to drive the cation migration across the interface, thereby mitigating the misfit strain. Our results offer new insights on how chemical roughening at oxide interfaces can be effective in stabilizing the structural integrity of the interface without the need for misfit dislocations. These findings offer a general formalism for understanding cation intermixing at highly strained oxide interfaces that are used in nanoelectronic devices.
Publisher: Oxford University Press (OUP)
Date: 24-07-2003
Publisher: World Scientific Pub Co Pte Lt
Date: 30-06-2010
DOI: 10.1142/S0217979210064848
Abstract: Nanostructured Cu -(2.5-10 vol. %) Al 2 O 3 nanocomposites were produced using high energy mechanical milling. For the as-milled Cu - Al 2 O 3 composite powder particles having Al 2 O 3 volume fractions of 2.5% and 5%, the increase in average microhardness is significant with the increase of milling time from 12 hours to 24 hours. With the increase of the content of Al 2 O 3 nanoparticles the microhardness increases and in the range of 255HV-270HV. The milled nanocomposite powders were heat treated at 150, 300, 400 and 500°C for 1 hour, respectively, to determine the thermal stability of the powder particles as a function of annealing temperature. The average microhardness increased/decreased for the Cu - Al 2 O 3 composites after annealing at 150°C due to the dislocation density, while increasing the annealing temperature to 300°C and 400°C the average microhardness almost remained mostly unchanged. Further increasing the annealing temperature to 500°C causes significant decrease in average microhardness due to reduction in dislocation density and coarsening of Cu grains of the Cu- Al 2 O 3 composite powders produced after 24 hours of milling. This paper is to report and discuss the changes of the microhardness of the material, caused by the compositions and processing conditions, used to fabricate the Cu -(2.5-10) vol. % Al 2 O 3 nanocomposite powders.
Publisher: AIP Publishing
Date: 26-01-2009
DOI: 10.1063/1.3078396
Abstract: The effect of thermal strain caused by the different thermal expansion coefficients (α) of the MgB2 and SiC phases on the electromagnetic properties was studied for SiC–MgB2 composite, which was made by premixing SiC and B, followed by Mg diffusion and reaction. Thermal strain in the MgB2 phase was demonstrated with x-ray diffraction, Raman spectroscopy, and transmission electron microscopy. In contrast to the common practice of improving the critical current density Jc and the upper critical field Hc2 of MgB2 through chemical substitution, by taking advantage of residual thermal strains, we are able to design a composite showing only a small decrease in the critical temperature and a little increase in resistivity but a significant improvement over the Jc and Hc2 of pure MgB2.
Publisher: Trans Tech Publications Ltd.
Date: 15-11-2007
Publisher: Elsevier BV
Date: 07-1991
Publisher: Elsevier BV
Date: 2019
Publisher: Wiley
Date: 02-2001
DOI: 10.1046/J.1365-2818.2001.00764.X
Abstract: A composite consisting of a brittle multiphase matrix containing both an Al-based quasicrystalline phase (psi) and an ordered body centred cubic phase (beta) and a relatively ductile ordered body centred cubic intermetallic FeAl phase has been developed as an abrasive wear-resistant coating material. It is applied as a 500 µm thick layer onto stainless steel substrates through plasma spray processing. The microstructure of such materials can be readily examined by optical and scanning electron microscopy, but the inherent difficulty of preparing transmission electron microscope (TEM) s les has inhibited higher resolution studies. However, the relatively recent development of the focused ion beam (FIB) miller as a tool in materials science provides a method ideal for the preparation of TEM specimens of these materials. In this study a coating consisting of a mixture of an Al-Cu-Fe based quasicrystal and FeAl+Cr was deposited on to a 304 stainless steel substrate. TEM specimens were prepared using a FIB and subjected to detailed microstructural characterization. The structure consisted of elongated bands of a FeAl phase about 100 nm in width and several micrometres in length, which enclosed more equiaxed regions about 1 µm in diameter that consisted of fine mixtures of quasicrystal and two Al-Fe-Cu phases isostructurally related to FeAl.
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 12-2016
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.SCITOTENV.2019.136101
Abstract: To examine the effect of rice straw biochar and the synergism with silicon on Cd immobilization, a Cd-contaminated acidic sandy loam paddy, polluted from emissions from industrial activity, was chosen in central South China. A field trial was conducted over three rice growing seasons during 2016-2017. Rice straw biochar (BR), produced by the pyrolysis of rice straw pellets at 450 °C, was amended at 10 t/ha (BR1), 20 t/ha (BR2), and supplemented with 0.75 t/ha sodium silicate (SS) at 10 t/ha, (BR1 + SS) and 20 t/ha (BR2 + SS), compared to the control without biochar and sodium silicate (BR0). BR supplemented with Si enhanced Cd soil immobilization and decreased Cd accumulation in rice plant within three rice seasons. Compared to BR0, BR + SS reduced Cd concentrations in grains by 19.5-73.7%, higher than that of 8.6-50.2% following BR. Cd bio-concentration factor of the root was reduced by an average of 54.6% from BR + SS and by 19.0% from BR, compared to BR0 in last two rice seasons. BR + SS significantly increased soil pH and available Si, and soil CaCl
Publisher: Springer Science and Business Media LLC
Date: 2013
Abstract: Two types of as-cast microstructures have been observed in a series of near-equiatomic FeNiMnAl alloys: 1) an ultrafine microstructure in Fe 30 Ni 20 Mn 20 Al 30 [1] and Fe 25 Ni 25 Mn 20 Al 30 , which consists of (Fe, Mn)-rich B2-ordered (ordered b.c.c.) and (Ni, Al)-rich L2 1 -ordered (Heusler) phases aligned along and 2) a fine two-phase microstructure in Fe 30 Ni 20 Mn 30 Al 20 and Fe 25 Ni 25 Mn 30 Al 20 , which consists of alternating (Fe, Mn)-rich f.c.c. and (Ni, Al)-rich B2-ordered platelets with an orientation relationship close to f.c.c (002) // B2 (002) f.c.c. [011] // B2 [001] [2]. The phases in Fe 25 Ni 25 Mn 20 Al 30 coarsened upon annealing with no significant change in the chemical partitioning. The hardness behavior was studied as a function of the annealing time at 823 K. AnL2 1 -to-B2 transition, which occurred at 573-623K, was observed using in-situ heating in a TEM. After annealing at 973 K for 100 h, needle-shaped clusters of (Fe, Mn)-rich precipitates were observed along the grain boundaries and in the matrix. The temperature dependence of the yield strength of as-cast Fe 25 Ni 25 Mn 20 Al 30 was also studied.
Publisher: Oxford University Press (OUP)
Date: 08-2014
Publisher: Elsevier BV
Date: 03-2016
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 10-2020
Publisher: Springer Science and Business Media LLC
Date: 08-01-2021
DOI: 10.1038/S41598-020-80377-Z
Abstract: Application of iron (Fe)- and silica (Si)-enhanced biochar compound fertilisers (BCF) stimulates rice yield by increasing plant uptake of mineral nutrients. With alterations of the nutrient status in roots, element homeostasis (e.g., Fe) in the biochar-treated rice root was related to the formation of biominerals on the plaque layer and in the cortex of roots. However, the in situ characteristics of formed biominerals at the micron and sub-micron scale remain unknown. In this study, rice seedlings ( Oryza sativa L. ) were grown in paddy soil treated with BCF and conventional fertilizer, respectively, for 30 days. The biochar-induced changes in nutrient accumulation in roots, and the elemental composition, distribution and speciation of the biomineral composites formed in the biochar-treated roots at the micron and sub-micron scale, were investigated by a range of techniques. Results of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) showed that biochar treatment significantly increased concentrations of nutrients (e.g., Fe, Si, and P) inside the root. Raman mapping and vibrating s le magnetometry identified biochar particles and magnetic Fe nanoparticles associated with the roots. With Fe plaque formation, higher concentrations of FeO x − and FeO x H − anions on the root surface than the interior were detected by time-of-flight secondary ionization mass spectrometry (ToF-SIMS). Analysis of data from scanning electron microscopy energy-dispersive spectroscopy (SEM-EDS), and from scanning transmission electron microscopy (STEM) coupled with EDS or energy electron loss spectroscopy (EELS), determined that Fe(III) oxide nanoparticles were accumulated in the crystalline fraction of the plaque and were co-localized with Si and P on the root surface. Iron-rich nanoparticles (Fe–Si nanocomposites with mixed oxidation states of Fe and ferritin) in the root cortex were identified by using aberration-corrected STEM and in situ EELS analysis, confirming the biomineralization and storage of Fe in the rice root. The findings from this study highlight that the deposition of Fe-rich nanocomposites occurs with contrasting chemical speciation in the Fe plaque and cortex of the rice root. This provides an improved understanding of the element homeostasis in rice with biochar-mineral fertilization.
Publisher: Elsevier BV
Date: 02-2002
Publisher: Elsevier BV
Date: 06-2017
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2012
End Date: 2012
Funder: Australian Research Council
View Funded ActivityStart Date: 2010
End Date: 2010
Funder: Australian Research Council
View Funded ActivityStart Date: 2013
End Date: 2013
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 2007
Funder: Australian Research Council
View Funded ActivityStart Date: 2009
End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2015
End Date: 2018
Funder: Australian Research Council
View Funded ActivityStart Date: 2013
End Date: 2013
Funder: Australian Research Council
View Funded ActivityStart Date: 2012
End Date: 2015
Funder: Australian Research Council
View Funded ActivityStart Date: 2004
End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2017
End Date: 2017
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 2005
Funder: Australian Research Council
View Funded ActivityStart Date: 2009
End Date: 2012
Funder: Australian Research Council
View Funded ActivityStart Date: 2010
End Date: 2014
Funder: Australian Research Council
View Funded ActivityStart Date: 2002
End Date: 2004
Funder: Australian Research Council
View Funded ActivityStart Date: 2009
End Date: 2011
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2015
End Date: 2017
Funder: Australian Research Council
View Funded ActivityStart Date: 2005
End Date: 2007
Funder: Australian Research Council
View Funded ActivityStart Date: 2004
End Date: 2006
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 2003
Funder: Australian Research Council
View Funded ActivityStart Date: 2005
End Date: 2005
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 2010
Funder: Australian Research Council
View Funded ActivityStart Date: 2005
End Date: 2006
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2004
End Date: 2006
Funder: Australian Research Council
View Funded ActivityStart Date: 2002
End Date: 2002
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 2003
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 2007
Funder: Australian Research Council
View Funded ActivityStart Date: 2002
End Date: 2005
Funder: Australian Research Council
View Funded ActivityStart Date: 2008
End Date: 2008
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 2003
Funder: Australian Research Council
View Funded ActivityStart Date: 2008
End Date: 2011
Funder: Australian Research Council
View Funded ActivityStart Date: 2010
End Date: 2010
Funder: Australian Research Council
View Funded ActivityStart Date: 2017
End Date: 2017
Funder: Australian Research Council
View Funded Activity