ORCID Profile
0000-0001-7514-4584
Current Organisations
University of New South Wales
,
Arizona State University
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Nanoscale Characterisation | Functional Materials | Materials Engineering | Materials engineering | Analytical Chemistry | Nanotechnology | Sensor Technology (Chemical aspects) | Metals and Alloy Materials | Immunological and Bioassay Methods | Chemical Characterisation of Materials | Nanomaterials | Nanobiotechnology | Nanoelectromechanical Systems | Functional materials | Condensed Matter Characterisation Technique Development |
Expanding Knowledge in Engineering | Expanding Knowledge in Technology | Expanding Knowledge in the Physical Sciences | Structural Metal Products | Scientific Instruments | Expanding Knowledge in the Information and Computing Sciences | Expanding Knowledge in the Biological Sciences |
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NA00524C
Abstract: The shape of nanoparticles is a key performance parameter for many applications, ranging from nanophotonics to nanomedicines.
Publisher: Elsevier
Date: 2008
Publisher: Oxford University Press (OUP)
Date: 07-2009
DOI: 10.1017/S1431927609098663
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009
Publisher: American Chemical Society (ACS)
Date: 11-06-2020
Publisher: Springer Science and Business Media LLC
Date: 15-05-2011
DOI: 10.1038/NCHEM.1049
Abstract: Water oxidation in all oxygenic photosynthetic organisms is catalysed by the Mn₄CaO₄ cluster of Photosystem II. This cluster has inspired the development of synthetic manganese catalysts for solar energy production. A photoelectrochemical device, made by impregnating a synthetic tetranuclear-manganese cluster into a Nafion matrix, has been shown to achieve efficient water oxidation catalysis. We report here in situ X-ray absorption spectroscopy and transmission electron microscopy studies that demonstrate that this cluster dissociates into Mn(II) compounds in the Nafion, which are then reoxidized to form dispersed nanoparticles of a disordered Mn(III/IV)-oxide phase. Cycling between the photoreduced product and this mineral-like solid is responsible for the observed photochemical water-oxidation catalysis. The original manganese cluster serves only as a precursor to the catalytically active material. The behaviour of Mn in Nafion therefore parallels its broader biogeochemistry, which is also dominated by cycles of oxidation into solid Mn(III/IV) oxides followed by photoreduction to Mn²⁺.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3EE40429C
Publisher: American Chemical Society (ACS)
Date: 18-08-2023
Publisher: Oxford University Press (OUP)
Date: 30-07-2020
Publisher: Springer International Publishing
Date: 2019
Publisher: AIP Publishing
Date: 16-05-2011
DOI: 10.1063/1.3590171
Abstract: Among the many considerable challenges faced in developing a rational basis for advanced alloy design, establishing accurate atomistic models is one of the most fundamental. Here we demonstrate how advanced imaging techniques in a double-aberration-corrected transmission electron microscope, combined with ab initio modeling, have been used to determine the atomic structure of embedded 1 nm thick T1 precipitates in precipitation-hardened Al–Li–Cu aerospace alloys. The results provide an accurate determination of the controversial T1 structure, and demonstrate how next-generation techniques permit the characterization of embedded nanostructures in alloys and other nanostructured materials.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CY00017F
Publisher: American Chemical Society (ACS)
Date: 13-01-2023
Publisher: American Physical Society (APS)
Date: 15-12-2016
Publisher: Oxford University Press (OUP)
Date: 30-07-2021
Publisher: Oxford University Press (OUP)
Date: 07-2009
DOI: 10.1017/S1431927609096470
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/CH15412
Abstract: The term amorphous metal oxide is becoming widely used in the catalysis community. The term is generally used when there are no apparent peaks in an X-ray diffraction pattern. However, the absence of such features in X-ray diffraction can mean that the material is either truly amorphous or that it is better described as nanocrystalline. By coprecipitating a sodium birnessite-like phase with and without phosphate (1.5 %), we are able to engineer two very similar but distinct materials – one that is nanocrystalline and the other that is amorphous. The two closely related phases were characterized with both Mn K-edge X-ray absorption spectroscopy and high-resolution transmission electron microscopy. These structural results were then correlated with catalytic and electrocatalytic activities for water oxidation catalysis. In this case, the amorphous phosphate-doped material was less catalytically active than the nanocrystalline material.
Publisher: Oxford University Press (OUP)
Date: 08-2019
Publisher: American Chemical Society (ACS)
Date: 06-06-2023
Publisher: Oxford University Press (OUP)
Date: 11-10-2006
DOI: 10.1017/S1431927606060582
Abstract: Exit wave restoration using focus series of images has become a widely used technique to improve image resolution and interpretation. To understand the effects of the imaging approximations used, we have critically compared the specimen exit wave functions restored using the efficient linear Wiener filter, with a general nonlinear maximum likelihood method.
Publisher: American Chemical Society (ACS)
Date: 14-01-2011
DOI: 10.1021/CS100025Y
Publisher: American Chemical Society (ACS)
Date: 24-10-2018
Publisher: IOP Publishing
Date: 22-02-2006
Publisher: Elsevier BV
Date: 10-2005
DOI: 10.1016/J.ULTRAMIC.2005.05.003
Abstract: We have developed a numerical approach for the accurate and efficient calculation of HREM image intensity formed using a partially coherent source. The approach is based on Monte Carlo integration, and is suitable for use in general image restoration methods using a series of images. The accuracy of this approach is compared with calculations based on the transmission cross coefficient (TCC) for strong scattering objects, as a function of the number of s ling points, defocus, atomic number and specimen thickness. Its efficiency is compared with that of exact TCC calculations based on equally-spaced s ling of the beam ergence and focal spread distributions. The results indicate that the Monte Carlo approach is particularly advantageous for nonlinear image restoration algorithms.
Publisher: Springer Science and Business Media LLC
Date: 05-02-2009
Publisher: American Chemical Society (ACS)
Date: 28-07-2010
DOI: 10.1021/NL101642F
Abstract: Accurate understanding of the structure of active sites is fundamentally important in predicting catalytic properties of heterogeneous nanocatalysts. We present an accurate determination of both experimental and theoretical atomic structures of surface monatomic steps on industrial platinum nanoparticles. This comparison reveals that the edges of nanoparticles can significantly alter the atomic positions of monatomic steps in their proximity, which can lead to substantial deviations in the catalytic properties compared with the extended surfaces.
Publisher: Elsevier BV
Date: 03-2012
Publisher: Springer International Publishing
Date: 2019
Publisher: American Chemical Society (ACS)
Date: 23-05-2022
Abstract: Nanodiamonds are at the heart of a plethora of emerging applications in areas ranging from nanocomposites and tribology to nanomedicine and quantum sensing. The development of alternative synthesis methods, a better understanding, and the availability of ultrasmall nanodiamonds of less than 3 nm size with a precisely engineered composition, including the particle surface and atomic defects in the diamond crystal lattice, would mark a leap forward for many existing and future applications. Yet today, we are unable to accurately control nanodiamond composition at the atomic scale, nor can we reliably create and isolate particles in this size range. In this perspective, we discuss recent advances, challenges, and opportunities in the synthesis, characterization, and application of ultrasmall nanodiamonds. We particularly focus on the advantages of bottom-up synthesis of these particles and critically assess the physicochemical properties of ultrasmall nanodiamonds, which significantly differ from those of larger particles and bulk diamond.
Publisher: Oxford University Press (OUP)
Date: 11-10-2006
DOI: 10.1017/S1431927606060612
Abstract: Methods for accurate and automated determination of the coefficients of the wave aberration function are compared with particular emphasis on measurements of higher order coefficients in corrected instruments. Experimental applications of aberration measurement to the determination of illumination isoplanicity and high precision local refinement of restored exit waves are also described.
Publisher: IOP Publishing
Date: 08-2008
Publisher: Oxford University Press (OUP)
Date: 03-01-2008
DOI: 10.1017/S1431927608080148
Abstract: Aberration correction leads to a substantial improvement in the directly interpretable resolution of transmission electron microscopes. Correction of the aberrations has been achieved electron-optically through a hexapole-based corrector and also indirectly by computational analysis of a focal or tilt series of images. These direct and indirect methods are complementary, and a combination of the two offers further advantages. Materials characterization has benefitted from the reduced delocalization and higher resolution in the corrected images. It is now possible, for ex le, to locate atomic columns at surfaces to higher accuracy and reliability. This article describes the JEM-2200FS in Oxford, which is equipped with correctors for both the image-forming and probe-forming lenses. Ex les of the use of this instrument in the characterization of nanocrystalline catalysts are given together with initial results combining direct and indirect methods. The double corrector configuration enables direct imaging of the corrected probe, and a potential confocal imaging mode is described. Finally, modifications to a second generation instrument are outlined.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4TA07085B
Abstract: CdO–NaI mixtures for pre-combustion CO 2 sorption were found to lose iodine by oxidation of iodide to higher-oxidised species. Morphology changes and the reversibility of the decay reaction were also investigated.
Publisher: Elsevier BV
Date: 02-2009
DOI: 10.1016/J.ULTRAMIC.2008.10.024
Abstract: The effects of amorphous layers on the quality of exit wave restorations have been investigated. Two independently developed software implementations for exit wave restoration have been used to simulated focal series of images of SrTiO3 with amorphous carbon layers incorporated. The restored exit waves have been compared both qualitatively and quantitatively. We have shown that amorphous layers have a strong impact on the quantitative measurements of atomic column positions, however, the error in the position measurements is still in the picometer range.
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3TA01995K
Abstract: This work will not only shed some light on understanding the dominant mechanism of piezocatalysis, but also uncover additional degrees of freedom, namely phase ratio within a phase boundary region, to further enhance the piezocatalytic efficiency.
Publisher: American Chemical Society (ACS)
Date: 07-11-2019
Publisher: American Physical Society (APS)
Date: 14-10-2019
Publisher: American Chemical Society (ACS)
Date: 29-03-2013
DOI: 10.1021/CM3041345
Publisher: Elsevier BV
Date: 09-2014
Publisher: Springer Science and Business Media LLC
Date: 17-12-2014
Publisher: AIP Publishing
Date: 27-05-2019
DOI: 10.1063/1.5100275
Abstract: Ge1−ySny alloys with compositions in the 0.15 & y & 0.30 range have been grown directly on Si substrates using a chemical vapor deposition approach that allows for growth temperatures as high as 290 °C. The films show structural properties that are consistent with results from earlier materials with much lower Sn concentrations. These include the lattice parameter and the Ge-Ge Raman frequency, which are found to depend linearly on composition. The simplicity of the structures, directly grown on Si, makes it possible to carry out detailed optical studies. Sharp absorption edges are found, reaching 8 μm near y = 0.3. The compositional dependence of edge energies shows a cubic deviation from the standard quadratic alloy expression. The cubic term may dramatically impact the ability of the alloys to cover the long-wavelength (8–12 μm) mid-IR atmospheric window.
Publisher: Wiley
Date: 14-04-2011
Abstract: Aqueous solutions of graphene oxide (GO) and citrate-stabilised gold nanoparticles (AuNPs) are two classic, negatively charged colloids. Using the surface plasmon resonance spectra of AuNPs as a probe, we illustrate how the two like-charged colloids interact with each other and in so doing, reveal the unique solution behaviour of GO. We demonstrate that the electrical double layer of the GO sheets in water plays a key role in controlling the interaction between GO and AuNPs, which displays a one-way gate effect. It is shown that GO can capture and disperse AuNPs in water in a controllable fashion, without the need for additional chemical linkers. This discovery allows the successful synthesis of uncapped, yet solution-dispersible metal-nanoparticle assemblies. Such metal nanostructures have long been pursued for nano-plasmonics and sensing applications, but have remained difficult to prepare using conventional polymer dispersants. This work also makes clear that the combination of the two-dimensional conformation of GO along with its large molecular size and self-contained functional groups allows it to act as a unique soluble nanocarrier/substrate (the thinnest, functionalised flat substrate possible in nature) for the synthesis of new, soluble functional materials.
Publisher: American Chemical Society (ACS)
Date: 11-10-2202
Publisher: Wiley
Date: 04-05-2007
Publisher: Elsevier BV
Date: 05-2008
Publisher: Wiley
Date: 18-09-2022
Abstract: The current approach to achieving superior energy storage density in dielectrics is to increase their breakdown strength, which often incurs heat generation and unexpected insulation failures, greatly deteriorating the stability and lifetime of devices. Here, a strategy is proposed for enhancing recoverable energy storage density ( W r ) while maintaining a high energy storage efficiency ( η) in glassy ferroelectrics by creating super tetragonal (super‐T) nanostructures around morphotropic phase boundary (MPB) rather than exploiting the intensely strong electric fields. Accordingly, a giant W r of ≈86 J cm −3 concomitant with a high η of ≈81% is acquired under a moderate electric field (1.7 MV cm −1 ) in thin films having MPB composition, namely, 0.94(Bi, Na)TiO 3 ‐0.06BaTiO 3 (BNBT), where the local super‐T polar clusters (tetragonality ≈1.25) are stabilized by interphase strain. To the knowledge of the authors, the W r of the engineered BNBT thin films represents a new record among all the oxide perovskites under a similar strength of electric field to date. The phase field simulation results ascertain that the improved W r is attributed to the local strain heterogeneity and the large spontaneous polarization primarily is originated from the super‐T polar clusters. The findings in this work present a genuine opportunity to develop ultrahigh‐energy‐density thin‐film capacitors for low‐electric‐field‐driven nano/microelectronics.
Publisher: American Chemical Society (ACS)
Date: 22-04-2016
DOI: 10.1021/ACS.LANGMUIR.6B00762
Abstract: Insects of the order Embioptera, known as embiopterans, embiids, or webspinners, weave silk fibers together into sheets to make shelters called galleries. In this study, we show that silk galleries produced by the embiopteran Antipaluria urichi exhibit a highly hydrophobic wetting state with high water adhesion macroscopically equivalent to the rose petal effect. Specifically, the silk sheets have advancing contact angles above 150°, but receding contact angle approaching 0°. The silk sheets consist of layered fiber bundles with single strands spaced by microscale gaps. Scanning and transmission electron microscopy (SEM, TEM) images of silk treated with organic solvent and gas chromatography mass spectrometry (GC-MS) of the organic extract support the presence of a lipid outer layer on the silk fibers. We use cryogenic SEM to demonstrate that water drops reside on only the first layer of the silk fibers. The area fraction of this sparse outer silk layers is 0.1 to 0.3, which according to the Cassie-Baxter equation yields an effective static contact angle of ∼130° even for a mildly hydrophobic lipid coating. Using high magnification optical imaging of the three phase contact line of a water droplet receding from the silk sheet, we show that the high adhesion of the drop stems from water pinning along bundles of multiple silk fibers. The bundles likely form when the drop contact line is pinned on in idual fibers and pulls them together as it recedes. The dynamic reorganization of the silk sheets during the droplet movement leads to formation of "super-pinning sites" that give embiopteran silk one of the strongest adhesions to water of any natural hydrophobic surface.
Publisher: Oxford University Press (OUP)
Date: 30-07-2021
Publisher: American Chemical Society (ACS)
Date: 14-07-2014
DOI: 10.1021/EF500834B
Publisher: American Chemical Society (ACS)
Date: 28-01-2021
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.ULTRAMIC.2014.11.019
Abstract: Off-axis electron holography provides a direct means of retrieving the phase of the wavefield in a transmission electron microscope, enabling measurement of electric and magnetic fields at length scales from microns to nanometers. To maximise the accuracy of the technique, it is important to acquire holograms using experimental conditions that optimise the phase resolution for a given spatial resolution. These conditions are determined by a number of competing parameters, especially the spatial coherence and the instrument instabilities. Here, we describe a simple, yet accurate, model for predicting the dose rate and exposure time that give the best phase resolution in a single hologram. Experimental studies were undertaken to verify the model of spatial coherence and instrument instabilities that are required for the optimisation. The model is applicable to electron holography in both standard mode and Lorentz mode, and it is relatively simple to apply.
Publisher: Springer Science and Business Media LLC
Date: 04-12-2012
DOI: 10.1038/NCOMMS2251
Abstract: Many applications proposed for graphene require multiple sheets be assembled into a monolithic structure. The ability to maintain structural integrity upon large deformation is essential to ensure a macroscopic material which functions reliably. However, it has remained a great challenge to achieve high elasticity in three-dimensional graphene networks. Here we report that the marriage of graphene chemistry with ice physics can lead to the formation of ultralight and superelastic graphene-based cellular monoliths. Mimicking the hierarchical structure of natural cork, the resulting materials can sustain their structural integrity under a load of >50,000 times their own weight and can rapidly recover from >80% compression. The unique biomimetic hierarchical structure also provides this new class of elastomers with exceptionally high energy absorption capability and good electrical conductivity. The successful synthesis of such fascinating materials paves the way to explore the application of graphene in a self-supporting, structurally adaptive and 3D macroscopic form.
Publisher: AIP Publishing
Date: 27-02-2006
DOI: 10.1063/1.2175481
Abstract: High-resolution (scanning) transmission electron micrographs taken on both aberration corrected and uncorrected microscopes, and indirect reconstructed images of mixed phase magnetite—maghemite nanoparticles all show the presence of {111} facets that terminate with enhanced contrast. This enhanced contrast is shown to be a real effect caused by the presence of additional octahedrally coordinated iron cations occupying the {111} terminating layers of these nanoparticle surfaces.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0NR00883D
Abstract: A reliable explanation for the underlying mechanism responsible for the persistent aggregation and self-assembly of colloidal 5 nm diamond nanoparticles is critical to the development of nanodiamond-based technologies. Although a number of mechanisms have been proposed, validation has been hindered by the inherent difficulty associated with the identification and characterisation of the inter-particle interfaces. In this paper we present results of high resolution aberration corrected electron microscopy and complementary computer simulations to explicate the features involved, and confirm the electrostatic interaction mechanism as the most probable cause for the formation of agglutinates and agglomerates of primary particles.
Publisher: Elsevier
Date: 2013
Publisher: American Chemical Society (ACS)
Date: 16-08-2013
DOI: 10.1021/JP4024316
Publisher: Elsevier BV
Date: 11-2008
Publisher: American Chemical Society (ACS)
Date: 12-04-2012
DOI: 10.1021/JZ3001823
Abstract: Porous platinum nanoparticles provide a route for the development of catalysts that use less platinum without sacrificing catalytic performance. Here, we examine porous platinum nanoparticles using a combination of in situ transmission electron microscopy and calculations based on a first-principles-parametrized thermodynamic model. Our experimental observations show that the initially irregular morphologies of the as-sythesized porous nanoparticles undergo changes at high temperatures to morphologies having faceted external surfaces with voids present in the interior of the particles. The increasing size of stable voids with increasing temperature, as predicted by the theoretical calculations, shows excellent agreement with the experimental findings. The results indicate that hollow-structured nanoparticles with an appropriate void-to-total-volume ratio can be stable at high temperatures.
Publisher: American Chemical Society (ACS)
Date: 05-01-2022
DOI: 10.1021/ACS.LANGMUIR.1C02283
Abstract: Detonation nanodiamonds have found numerous potential applications in a erse array of fields such as biomedical imaging and drug delivery. Here, we systematically characterized non-functionalized and polyglycerol-functionalized detonation nanodiamond particles (DNPs) dispersed in aqueous suspensions at different ionic strengths (∼1.0 × 10
Publisher: Elsevier BV
Date: 03-2015
Publisher: Oxford University Press (OUP)
Date: 08-2019
Publisher: American Chemical Society (ACS)
Date: 31-12-2013
DOI: 10.1021/JA311366K
Abstract: Recent successes in forming different shaped face centered cubic (fcc) metal nanostructures has enabled a greater understanding of nanocrystal growth mechanisms. Here we extend this understanding to the synthesis of hexagonally close packed (hcp) metal nanostructures, to form uniquely faceted ruthenium nanocrystals with a well-defined hourglass shape. The hourglass nanocrystals are formed in a three-step thermodynamic growth process with dodecylamine as the organic stabilizer. The hourglass nanocrystals are then shown to readily self-assemble to form a new type of nanocrystal superlattice.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3TA12087B
Publisher: Elsevier BV
Date: 04-2019
Publisher: Wiley
Date: 23-12-2017
Publisher: Wiley
Date: 30-11-2015
Abstract: We report that films screen printed from nickel oxide (NiO) nanoparticles and microballs are efficient electrocatalysts for water oxidation under near-neutral and alkaline conditions. Investigations of the composition and structure of the screen-printed films by X-ray diffraction, X-ray absorption spectroscopy, and scanning electron microscopy confirmed that the material was present as the cubic NiO phase. Comparison of the catalytic activity of the microball films to that of films fabricated by using NiO nanoparticles, under similar experimental conditions, revealed that the microball films outperform nanoparticle films of similar thickness owing to a more porous structure and higher surface area. A thinner, less-resistive NiO nanoparticle film, however, was found to have higher activity per Ni atom. Anodization in borate buffer significantly improved the activity of all three films. X-ray photoelectron spectroscopy showed that during anodization, a mixed nickel oxyhydroxide phase formed on the surface of all films, which could account for the improved activity. Impedance spectroscopy revealed that surface traps contribute significantly to the resistance of the NiO films. On anodization, the trap state resistance of all films was reduced, which led to significant improvements in activity. In 1.00 m NaOH, both the microball and nanoparticle films exhibit high long-term stability and produce a stable current density of approximately 30 mA cm(-2) at 600 mV overpotential.
Publisher: Oxford University Press (OUP)
Date: 30-07-2021
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.ULTRAMIC.2015.09.004
Abstract: The performance of a direct detection camera (DDC) is evaluated in the context of off-axis electron holographic experiments in a transmission electron microscope. Its performance is also compared directly with that of a conventional charge-coupled device (CCD) camera. The DDC evaluated here can be operated either by the detection of in idual electron events (counting mode) or by the effective integration of many such events during a given exposure time (linear mode). It is demonstrated that the improved modulation transfer functions and detective quantum efficiencies of both modes of the DDC give rise to significant benefits over the conventional CCD cameras, specifically, a significant improvement in the visibility of the holographic fringes and a reduction of the statistical error in the phase of the reconstructed electron wave function. The DDC's linear mode, which can handle higher dose rates, allows optimisation of the dose rate to achieve the best phase resolution for a wide variety of experimental conditions. For suitable conditions, the counting mode can potentially utilise a significantly lower dose to achieve a phase resolution that is comparable to that achieved using the linear mode. The use of multiple holograms and correlation techniques to increase the total dose in counting mode is also demonstrated.
Publisher: IOP Publishing
Date: 08-2008
Publisher: Springer Science and Business Media LLC
Date: 15-05-2018
DOI: 10.1038/S41467-018-04328-Z
Abstract: Akin to the enormous number of discoveries made through traditional semiconductor alloys, alloying selected 2D semiconductors enables engineering of their electronic structure for a wide range of new applications. 2D alloys have been demonstrated when two components crystallized in the same phase, and their bandgaps displayed predictable monotonic variation. By stabilizing previously unobserved compositions and phases of GaSe 1− x Te x at nanoscales on GaAs(111), we demonstrate abnormal band bowing effects and phase instability region when components crystallize in different phases. Advanced microscopy and spectroscopy measurements show as tellurium is alloyed into GaSe, nanostructures undergo hexagonal to monoclinic and isotropic to anisotropic transition. There exists an instability region (0.56 x 0.67) where both phases compete and coexist, and two different bandgap values can be found at the same composition leading to anomalous band bowing effects. Results highlight unique alloying effects, not existing in single-phase alloys, and phase engineering routes for potential applications in photonic and electronics.
Publisher: IOP Publishing
Date: 22-02-2006
Publisher: Elsevier BV
Date: 08-2018
Publisher: American Chemical Society (ACS)
Date: 18-04-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6NR01888B
Abstract: Detonation nanodiamond particles (DND) contain highly-stable nitrogen-vacancy (N-V) centers, making it important for quantum-optical and biotechnology applications. However, due to the small particle size, the N-V concentrations are believed to be intrinsically very low, spawning efforts to understand the formation of N-V centers and vacancies, and increase their concentration. Here we show that vacancies in DND can be detected and quantified using simulation-aided electron energy loss spectroscopy. Despite the small particle size, we find that vacancies exist at concentrations of about 1 at%. Based on this experimental finding, we use ab initio calculations to predict that about one fifth of vacancies in DND form N-V centers. The ability to directly detect and quantify vacancies in DND, and predict the corresponding N-V formation probability, has a significant impact to those emerging technologies where higher concentrations and better dispersion of N-V centres are critically required.
Publisher: Wiley
Date: 12-07-2011
DOI: 10.1002/POLA.24853
Abstract: Bioinspired core‐bound polymeric micelles, based on hydrogen bonding and photo‐crosslinking, of thymine have been prepared from poly(vinylbenzylthymine)‐ b ‐poly(vinylbenzyltriethylammonium chloride). The hiphilic block copolymer was synthesized by 2,2‐tetramethylpiperidin‐1‐oxyl‐mediated living radical polymerization in water/ethylene glycol solution. Micelle characterization and critical micelle concentration measurements demonstrated that the hydrogen bonding of the attached thymine units stabilizes the micelles. Further, core‐crosslinked polymeric micelles were formed by ultraviolet (UV) radiation showing that the stability of the micelle could be controlled by the UV crosslinking of the attached thymines. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3TA14738J
Abstract: High degree of structural disorders in birnessite phase particles in Nafion are responsible for high photo-electrochemical water-oxidation activity.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9NA00567F
Abstract: We show that clinical gadolinium-based contrast agents can form Gd 3+ -ferritin nanoparticles under physiological conditions. We suggest they can contribute to the T 1 intensity changes in ferritin-rich brain areas observed in patients examined by MRI.
Publisher: MDPI AG
Date: 14-10-2021
DOI: 10.3390/NANO11102706
Abstract: The morphology of nanoparticles governs their properties for a range of important applications. Thus, the ability to statistically correlate this key particle performance parameter is paramount in achieving accurate control of nanoparticle properties. Among several effective techniques for morphological characterization of nanoparticles, transmission electron microscopy (TEM) can provide a direct, accurate characterization of the details of nanoparticle structures and morphology at atomic resolution. However, manually analyzing a large number of TEM images is laborious. In this work, we demonstrate an efficient, robust and highly automated unsupervised machine learning method for the metrology of nanoparticle systems based on TEM images. Our method not only can achieve statistically significant analysis, but it is also robust against variable image quality, imaging modalities, and particle dispersions. The ability to efficiently gain statistically significant particle metrology is critical in advancing precise particle synthesis and accurate property control.
Publisher: Wiley
Date: 15-07-2018
Abstract: Achieving stability with highly active Ru nanoparticles for electrocatalysis is a major challenge for the oxygen evolution reaction. As improved stability of Ru catalysts has been shown for bulk surfaces with low-index facets, there is an opportunity to incorporate these stable facets into Ru nanoparticles. Now, a new solution synthesis is presented in which hexagonal close-packed structured Ru is grown on Au to form nanoparticles with 3D branches. Exposing low-index facets on these 3D branches creates stable reaction kinetics to achieve high activity and the highest stability observed for Ru nanoparticle oxygen evolution reaction catalysts. These design principles provide a synthetic strategy to achieve stable and active electrocatalysts.
Publisher: Elsevier BV
Date: 11-2021
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/CH12016
Abstract: One of the most promising approaches to addressing the challenges of securing cheap and renewable energy sources is to design catalysts from earth abundant materials capable of promoting key chemical reactions including splitting water into hydrogen and oxygen (2H2O → 2H2 + O2) as well as both the oxidation (H2 → 2H+) and reduction (2H+ → H2) of hydrogen. Key to elucidating the origin of catalytic activity and improving catalyst design is determining molecular-level structure, in both the ‘resting state’ and in the functioning ‘active state’ of the catalysts. Herein, we explore some of the analytical challenges important for designing and studying new catalytic materials for making and using hydrogen. We discuss a case study that used the combined approach of X-ray absorption spectroscopy and transmission electron microscopy to understand the fate of the molecular cluster, [Mn4O4L6]+, in Nafion.
Publisher: Oxford University Press (OUP)
Date: 08-2008
DOI: 10.1017/S1431927608086728
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Publisher: American Scientific Publishers
Date: 09-2016
Publisher: Wiley
Date: 17-06-2014
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9NR08984E
Abstract: We use direct imaging and dynamic light scattering to reveal the previously unknown dynamic self-assembly of detonation nanodiamond dispersions in water which have been purified without additional surface modification.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NR04847C
Abstract: Detonation nanodiamonds self-assemble into fractal-like structures in aqueous suspensions. Our work shows that the size and shape of these structures strongly depend on the particle concentration but not on the ionic strength of the suspension.
Publisher: Elsevier BV
Date: 05-2020
Publisher: International Union of Crystallography (IUCr)
Date: 12-01-2012
Publisher: Elsevier BV
Date: 03-2006
DOI: 10.1016/J.ULTRAMIC.2005.09.004
Abstract: Next generation aberration correctors will not only eliminate the third-order spherical aberration, but also improve the information limit by correction of chromatic aberration. As a result of these improvements, higher order aberrations, which have largely been neglected in image analysis, will become important. In this paper, we concern ourselves with situations where sub-A resolution can be achieved, and where the third-order spherical aberration is corrected and the fifth-order spherical aberration is measurable. We derive formulae to explore the maximum value of the fifth-order spherical aberration for directly interpretable imaging and discuss the optimum imaging conditions and their applicable range.
Publisher: American Chemical Society (ACS)
Date: 16-11-2022
Abstract: Although the solid-state cooling technology based on electrocaloric response has been considered a promising refrigeration solution for microdevices, the mediocre dipolar entropy change Δ
Publisher: American Chemical Society (ACS)
Date: 22-03-2021
Publisher: American Physical Society (APS)
Date: 28-07-2010
Publisher: American Chemical Society (ACS)
Date: 25-10-2019
Publisher: Oxford University Press (OUP)
Date: 24-09-2003
Abstract: Different optimal operating conditions for a C3-corrected transmission electron microscope were compared for both conventional field emission sources and for the next generation of monochromated instruments. In particular, the contrast transfer functions and corresponding wave aberration functions for two previously proposed optimal conditions in which C3 is adjusted to compensate, respectively, C5 or Cc are critically compared. The results indicate that in the presence of a small positive C5 the former provides flat transfer to the information limit whereas the latter shows oscillatory transfer at high spatial frequencies, which is more pronounced for the monochromated instrument. The effects of this behaviour were further investigated through multislice simulations of Si [110] and diamond [110] under the C5-limited condition. These confirm that for the former structure with an interatomic separation of 0.14 nm this aberration has little influence, but that for the latter with a sub-0.1 nm interatomic separation its presence leads to a restricted defocus range over which the structure is faithfully resolved.
Publisher: Elsevier BV
Date: 07-2006
DOI: 10.1016/J.MICRON.2006.01.005
Abstract: Mixed phase Fe3O4-gamma-Fe2O3 (magnetite-maghemite) iron oxide nanoparticles have been fabricated by colloidal routes. HRTEM/HRSTEM images of the nanoparticles show the presence of [111] facets that terminate with enhanced contrast, which is shown to be caused by the presence of additional cations at the edges of the nanoparticles. HRTEM images were taken on a FEI CM200 FEGTEM, a JEOL 3100 with a LaB6 source, and a double aberration corrected JEOL-JEM 2200FS FEGTEM. The enhanced contrast effect was observed on the [111] surface atomic layers resolved using each machine. HRSTEM images, taken on an aberration corrected STEM, resolved enhanced contrast at specific surface sites. Exit wave reconstruction was also carried out on focal series taken on a double aberration corrected JEOL-JEM 2200FS and showed similar highly resolved enhanced contrast at specific surface cation sites. It is apparent that additional cations are occupying the [111] terminating layers of these nanoparticle surfaces. The use of different microscopes and techniques in this paper provides strong evidence that the enhanced contrast is a real effect and not an effect caused by microscope aberrations.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0NR03470C
Abstract: Coarse-grained molecular dynamics simulations of diamond nanoparticles were performed to investigate the effects of size polydispersity on three polyhedral shapes chosen to span a erse space of surface interactions.
Publisher: American Chemical Society (ACS)
Date: 05-04-2023
Publisher: Oxford University Press (OUP)
Date: 07-2009
DOI: 10.1017/S1431927609094744
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2EE23862D
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.ULTRAMIC.2014.08.011
Abstract: It is demonstrated how an electron-optical arrangement consisting of two electron biprisms can be used to generate three-wave vortex lattices with effective lattice spacings between 0.1 and 1 nm. The presence of vortices in these lattices was verified by using a third biprism to perform direct phase measurements via off-axis electron holography. The use of three-wave lattices for nanoscale electromagnetic field measurements via vortex interferometry is discussed, including the accuracy of vortex position measurements and the interpretation of three-wave vortex lattices in the presence of partial spatial coherence.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7NH00125H
Abstract: Sub 3 nm diamond particles show size- and shape-dependent surface reconstructions, which have significant impact to their functionality and performance.
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 04-2022
End Date: 03-2025
Amount: $465,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2023
End Date: 12-2025
Amount: $438,479.00
Funder: Australian Research Council
View Funded ActivityStart Date: 04-2021
End Date: 04-2023
Amount: $468,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 03-2023
End Date: 03-2027
Amount: $3,975,864.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2021
End Date: 12-2023
Amount: $950,000.00
Funder: Australian Research Council
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