ORCID Profile
0000-0001-7764-5067
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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.
Condensed Matter Physics | Metals and Alloy Materials | Condensed Matter Characterisation Technique Development | Functional Materials | Materials Engineering | Composite and Hybrid Materials | Surfaces and Structural Properties of Condensed Matter | Nanoscale Characterisation | Condensed Matter Imaging |
Expanding Knowledge in the Physical Sciences | Energy Conservation and Efficiency in Transport | Structural Glass and Glass Products | Expanding Knowledge in the Earth Sciences | Expanding Knowledge in the Chemical Sciences | Structural Metal Products | Expanding Knowledge in Engineering | Expanding Knowledge in Technology
Publisher: American Physical Society (APS)
Date: 12-09-2011
Publisher: Springer Science and Business Media LLC
Date: 09-10-2008
Publisher: The Optical Society
Date: 13-05-2011
DOI: 10.1364/OL.36.001878
Publisher: Elsevier BV
Date: 2012
Publisher: Wiley
Date: 12-07-2017
Publisher: IEEE
Date: 05-2008
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2TA05083H
Abstract: A range of advanced imaging techniques are employed to study the micron- and nano-scale morphology of a polymer/non-fullerene acceptor blend. Cryo-electron microscopy in particular reveals nanoscale variations in molecular orientation and order.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6NR00075D
Abstract: The aqueous dispersibility of carbon-based nanomaterials, namely graphene oxide (GO), reduced graphene oxide (rGO) and carbon nanotubes (CNTs), can be controlled by light via the photoisomerisation of a photoswitchable surfactant molecule adsorbed to the surface of these materials.
Publisher: Wiley
Date: 26-04-2018
Abstract: Organic-inorganic hybrid perovskites, such as CH
Publisher: Elsevier BV
Date: 08-2018
Publisher: American Chemical Society (ACS)
Date: 27-06-2016
Publisher: Springer Science and Business Media LLC
Date: 11-2001
Abstract: Solid-phase epitaxy was examined in deep amorphous volumes formed in silicon wafers by multi-energy self-implantation through a mask. Crystallization was effected at elevated temperatures with the amorphous volume being transformed at both lateral and vertical interfaces. S le topology was mapped using an atomic force microscope. Details of the process were clarified with both plan-view and cross-sectional transmission electron microscopy analyses. Crystallization of the amorphous volumes resulted in the incorporation of a surprisingly large number of dislocations. These arose from a variety of sources. Some of the secondary structures were identified to occur uniquely from the crystallization of volumes in this particular geometry.
Publisher: Elsevier BV
Date: 10-2013
Publisher: SPIE
Date: 23-02-2005
DOI: 10.1117/12.582855
Publisher: Elsevier BV
Date: 04-2015
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NA00382G
Abstract: Weaving nanostructures with site-specific ion induced bidirectional bending and a typical 3D folded nanostructure in the form of a mesh.
Publisher: AIP Publishing
Date: 19-11-2007
DOI: 10.1063/1.2805189
Abstract: Multiwavelength Raman spectroscopy has been used to study the structure of hydrogenated amorphous carbon films synthesized by plasma-enhanced chemical vapor deposition. The analysis of different parameters from the Raman spectra demonstrates that the diameter, structural, and topological orders of the sp2-bonded ring clusters increase with increasing fractions of hydrogen in the source gas. We report the existence of an unusual peak at 867cm−1 that in such extended clusters of aromatic rings, could correspond to a graphitic mode activated by a relaxation of the phonon selection-rule resulting from defects.
Publisher: Elsevier BV
Date: 04-2016
Publisher: Wiley
Date: 03-2018
Publisher: Wiley
Date: 22-10-2021
Abstract: We developed a series of highly crystalline double‐cable conjugated polymers for application in single‐component organic solar cells (SCOSCs). These polymers contain conjugated backbones as electron donor and pendant perylene bisimide units (PBIs) as electron acceptor. PBIs are connected to the backbone via alkyl units varying from hexyl (C 6 H 12 ) to eicosyl (C 20 H 40 ) as flexible linkers. For double‐cable polymers with short linkers, the PBIs tend to stack in a head‐to‐head fashion, resulting in large d ‐spacings (e.g. 64 Å for the polymer P12 with C 12 H 24 linker) along the lamellar stacking direction. When the length of the linker groups is longer than a certain length, the PBIs instead adopt a more ordered packing likely via H ‐aggregation, resulting in short d ‐spacings (e.g. 50 Å for the polymer P16 with C 16 H 32 linker). This work highlights the importance of linker length on the molecular packing of the acceptor units and the influences on the photovoltaic performance of SCOSCs.
Publisher: Elsevier BV
Date: 2003
Publisher: IOP Publishing
Date: 05-12-2018
Publisher: Wiley
Date: 09-07-2021
Abstract: Plasmonic apertures permit optical fields to be concentrated into sub‐wavelength regions. This enhances the optical gradient force, enabling the precise trapping of nanomaterials such as quantum dots, proteins, and DNA molecules at modest laser powers. Double nanoholes, coaxial apertures, bowtie apertures, and other structures have been studied as plasmonic nanotweezers, with the design process generally comprising intuition followed by electromagnetic simulations with parameter sweeps. Here, instead, a computational algorithm is used to design plasmonic apertures for nanoparticle trapping. The resultant apertures have highly irregular shapes that, in combination with ring couplers also optimized by algorithm, are predicted to generate trapping forces more than an order of magnitude greater than those from the double nanohole design used as the optimization starting point. The designs are realized by fabricating precision apertures with a helium/neon ion microscope and are studied them by cathodoluminescence and optical trapping. It is shown that, at every laser intensity, the algorithm‐designed apertures can trap particles more tightly than the double nanohole.
Publisher: Wiley
Date: 10-04-2001
Abstract: The evolution of polygonal‐shaped nanoholes on the (100) surface of germanium, aided by focused ion beam induced self‐organization, is presented. The energetic beam of ions creates a viscous phase which, at a thermodynamical minimum, leads to surface self‐organization. A directed viscous‐flow along the predefined nanoholes provides well‐ordered polygonal nanostructures, ranging from triangles to hexagons and octagons, as desired. The amorphization exhibiting a confined viscous‐flow at the walls of nanoholes is attributed to the localized melting zones induced by site‐specific thermal spikes during ion irradiation, as revealed by microscopy and molecular dynamics studies. This leads to a local self‐organization in the vicinity of each circular nanohole via a viscous‐fingering process at the nanoscale. Such controlled self‐organization, with the help of a predefined scanning grid, transforms the circular holes into the desired polygonal shape. The present morphology manipulation promises to surmount the barriers concerning the size reduction efforts in the field of nanofabrication.
Publisher: American Chemical Society (ACS)
Date: 18-12-2023
Abstract: Here, we systematically study the effect of fluorination on the performance of all-polymer solar cells by employing a naphthalene diimide (NDI)-based polymer acceptor with thiophene-flanked phenyl co-monomer. Fluorination of the phenyl co-monomer with either two or four fluorine units is used to create a series of acceptor polymers with either no fluorination (PNDITPhT), bifluorination (PNDITF2T), or tetrafluorination (PNDITF4T). In blends with the donor polymer PTB7-Th, fluorination results in an increase in power conversion efficiency from 3.1 to 4.6% despite a decrease in open-circuit voltage from 0.86 V (unfluorinated) to 0.78 V (tetrafluorinated). Countering this decrease in open-circuit voltage is an increase in short-circuit current from 7.7 to 11.7 mA/cm
Publisher: American Physical Society (APS)
Date: 05-2007
Publisher: Wiley
Date: 13-01-2015
Abstract: Porosity loss, also known as physical aging, in glassy polymers h ers their long term use in gas separations. Unprecedented interactions of porous aromatic frameworks (PAFs) with these polymers offer the potential to control and exploit physical aging for drastically enhanced separation efficiency. PAF-1 is used in the archetypal polymer of intrinsic microporosity (PIM), PIM-1, to achieve three significant outcomes. 1) hydrogen permeability is drastically enhanced by 375% to 5500 Barrer. 2) Physical aging is controlled causing the selectivity for H2 over N2 to increase from 4.5 to 13 over 400 days of aging. 3) The improvement with age of the membrane is exploited to recover up to 98% of H2 from gas mixtures with N2 . This process is critical for the use of ammonia as a H2 storage medium. The tethering of polymer side chains within PAF-1 pores is responsible for maintaining H2 transport pathways, whilst the larger N2 pathways gradually collapse.
Publisher: Oxford University Press (OUP)
Date: 31-07-2006
DOI: 10.1017/S143192760606452X
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Publisher: American Physical Society (APS)
Date: 18-05-2016
Publisher: American Physical Society (APS)
Date: 04-09-2007
Publisher: Elsevier BV
Date: 04-2017
Publisher: International Union of Crystallography (IUCr)
Date: 09-07-2015
DOI: 10.1107/S2053273315011845
Abstract: The interpretation of angular symmetries in electron nanodiffraction patterns from thin amorphous specimens is examined. It is found that in general there are odd symmetries in experimental electron nanodiffraction patterns. Using simulation, it is demonstrated that this effect can be attributed to dynamical scattering, rather than other ergences from the ideal experimental conditions such as probe-forming lens aberrations and camera noise. The departure of opposing diffracted intensities from Friedel's law in the phase grating formalism is calculated using a general structure factor for disordered materials. On the basis of this, a simple correction procedure is suggested to recover the kinematical angular symmetries, and thus readily interpretable information that reflects the symmetries of the original projected object. This correction is numerically tested using both the phase object and multislice calculations, and is demonstrated to fully recover all the kinematical diffracted symmetries from a simulated atomic model of a metallic glass.
Publisher: American Chemical Society (ACS)
Date: 27-10-2020
Publisher: Elsevier BV
Date: 12-2015
Publisher: Oxford University Press (OUP)
Date: 07-2012
DOI: 10.1017/S1431927612009579
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.
Publisher: AIP Publishing
Date: 11-2008
DOI: 10.1063/1.3009971
Abstract: The morphology and structural order of thermally deposited and annealed amorphous As2S3 films have been investigated using high resolution transmission electron microscopy. It was found that both the as-deposited and annealed films contained sparsely distributed nanocrystallites of the orpiment As2S3 crystalline phase. However, from selected area electron diffraction both films appeared amorphous. Fluctuation electron microscopy revealed that the as-deposited film contained greater nanoscale inhomogeneity. Low temperature annealing reduced the nanoscale inhomogeneity and resulted in a more homogeneous and energetically favorable network. The reduction in nanoscale inhomogeneity upon low temperature annealing was accompanied by the appearance of a first sharp diffraction peak in the diffraction pattern. This first-sharp diffraction peak has been attributed to chemical ordering of interstitial voids. Our measurements suggest that this chemical short-range ordering is associated with the dissolution of the energetically unfavorable larger correlated structures that contribute to the inhomogeneity of the as-deposited film.
Publisher: Wiley
Date: 08-05-2020
Publisher: Elsevier BV
Date: 04-2001
Publisher: Wiley
Date: 16-04-2014
Abstract: Aging in super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP), poly(4-methyl-2-pentyne) (PMP), and polymers with intrinsic microporosity (PIM-1) reduces gas permeabilities and limits their application as gas-separation membranes. While super glassy polymers are initially very porous, and ultra-permeable, they quickly pack into a denser phase becoming less porous and permeable. This age-old problem has been solved by adding an ultraporous additive that maintains the low density, porous, initial stage of super glassy polymers through absorbing a portion of the polymer chains within its pores thereby holding the chains in their open position. This result is the first time that aging in super glassy polymers is inhibited whilst maintaining enhanced CO2 permeability for one year and improving CO2/N2 selectivity. This approach could allow super glassy polymers to be revisited for commercial application in gas separations.
Publisher: Beilstein Institut
Date: 18-05-2018
DOI: 10.3762/BJNANO.9.140
Abstract: Here we present the results of an investigation of resonances of azimuthal trimer arrangements of rectangular slots in a gold film on a glass substrate using cathodoluminescence (CL) as a probe. The variation in the CL signal collected from specific locations on the s le as a function of wavelength and the spatial dependence of emission into different wavelength bands provides considerable insight into the resonant modes, particularly sub-radiant modes, of these apertures. By comparing our experimental results with electromagnetic simulations we are able to identify a Fabry–Pérot mode of these cavities as well as resonances associated with the excitation of surface plasmon polaritons on the air–gold boundary. We obtain evidence for the excitation of dark (also known as sub-radiant) modes of apertures and aperture ensembles.
Publisher: Oxford University Press (OUP)
Date: 31-07-2006
DOI: 10.1017/S1431927606064270
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Publisher: The Electrochemical Society
Date: 2003
DOI: 10.1149/1.1557084
Publisher: American Chemical Society (ACS)
Date: 13-02-2017
Abstract: Asymmetric nanoparticle trimers composed of particles with increasing diameter act as "plasmonic lenses" and have been predicted to exhibit ultrahigh confinement of electromagnetic energy in the space between the two smallest particles. Here we present an electrostatic self-assembly approach for creating gold nanoparticle trimers with an assembly yield of over 60%. We demonstrate that the trimer assembly leads to characteristic red-shifts and show the localization of the relevant plasmon modes by means of cathodoluminescence and electron energy loss spectroscopy. The results are analyzed in terms of surface plasmon hybridization.
Publisher: American Physical Society (APS)
Date: 23-04-2009
Publisher: American Physical Society (APS)
Date: 09-06-2016
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0NR02787A
Abstract: Nanoparticle dimers composed of different metals or metal oxides, as well as different shapes and sizes, are of wide interest for applications ranging from nanoplasmonic sensing to nanooptics to biomedical engineering.
Publisher: Wiley
Date: 08-04-2023
Abstract: The waveguide modes in chemically‐grown silver nanowires on silicon nitride substrates are observed using spectrally‐ and spatially‐resolved cathodoluminescence (CL) excited by high‐energy electrons in a scanning electron microscope. The presence of a long‐range, travelling surface plasmon mode modulates the coupling efficiency of the incident electron energy into the nanowires, which is observed as oscillations in the measured CL with the point of excitation by the focused electron beam. The experimental data are modeled using the theory of surface plasmon polariton modes in cylindrical metal waveguides, enabling the complex mode wavenumbers and excitation strength of the long‐range surface plasmon mode to be extracted. The experiments yield insight into the energy transfer mechanisms between fast electrons and coherent oscillations in surface charge density in metal nanowires and the relative litudes of the radiative processes excited in the wire by the electron.
Publisher: American Physical Society (APS)
Date: 18-03-2020
Publisher: IOP Publishing
Date: 25-08-2020
Publisher: Elsevier BV
Date: 07-2011
DOI: 10.1016/J.ULTRAMIC.2011.03.007
Abstract: Single defocused transmission electron microscope phase contrast images are used to reconstruct the projected thickness map of a single-material object. The algorithm is non-iterative and stable, and we extend it to account for the presence of spherical aberration in the objective optics. The technique can reconstruct the projected thickness map of general single-material objects in the strong phase/weak litude regime. It is sensitive to any excursions in the projected thickness from the average, and ideal for examining voids and free volume accumulation in amorphous/glassy materials at the nanometer scale. The resolution of the technique depends on the choice of defocus and the thickness of the specimen. In a certain regime, we demonstrate that variations in the transverse projected thickness with a lateral diameter of ∼ 0.25 nm may be detected. We use our algorithm to quantitatively reconstruct the projected thickness of latex sphere test specimens from single defocused electron micrographs. We demonstrate that the reconstruction has a large tolerance for error in the input parameters. Simulations confirm that the technique is quantitative, and demonstrate that the origin of low-frequency artifacts is an instability due to noise. We show that the autocorrelation of the projected thickness map may be used to measure the size of open structures in the object using both simulation and latex sphere data.
Publisher: Proceedings of the National Academy of Sciences
Date: 13-09-2017
Abstract: Local structure and symmetry in amorphous materials and glasses may play a critical role in their formation and properties yet are notoriously hard to measure. Here, we demonstrate a direct method for measuring the proportions of polyhedra with different local point symmetries in amorphous colloidal packings, using small-volume transmission diffraction patterns. We show that local order is tuned by the interaction potential between microspheres and the method of preparation. This methodology can be readily applied to a broad range of disordered materials and packings to probe for universal features in their structure. It also has the potential to quantify local order in liquid, undercooled, and liquid–crystal systems approaching a phase transition.
Publisher: Oxford University Press (OUP)
Date: 28-11-2014
DOI: 10.1017/S1431927613013779
Abstract: High-resolution radial distribution functions of as-implanted and thermally relaxed amorphous silicon created by ion implantation were measured using tilted-illumination selected area electron diffraction at room temperature. The diffracted intensities were measured out to a maximum scattering vector 2 sin(θ)/λ of 3.3–3.7 Å −1 . The volume-averaged pair-correlation statistics of as-implanted and relaxed ion-implanted amorphous silicon are virtually indistinguishable with coordination numbers of 3.7 ± 0.3 and 3.9 ± 0.3 (for neighbors closer than 3 Å) and average bond angles of 109 ± 0.5° and 110 ± 0.6°, respectively. The atomic rearrangements in ion-implanted amorphous silicon due to a low temperature anneal are subtle.
Publisher: Wiley
Date: 21-08-2017
DOI: 10.1002/POLB.24151
Publisher: Informa UK Limited
Date: 26-08-2016
Publisher: American Chemical Society (ACS)
Date: 12-01-2017
Publisher: American Association for the Advancement of Science (AAAS)
Date: 18-03-2022
Abstract: The mechanical properties of crystals are controlled by the translational symmetry of their structures. But for glasses with a disordered structure, the link between the symmetry of local particle arrangements and stability is not well established. In this contribution, we provide experimental verification that the centrosymmetry of nearest-neighbor polyhedra in a glass strongly correlates with the local mechanical stability. We examine the distribution of local stability and local centrosymmetry in a glass during aging and deformation using microbeam x-ray scattering. These measurements reveal the underlying relationship between particle-level structure and larger-scale behavior and demonstrate that spatially connected, coordinated local transformations to lower symmetry structures are fundamental to these phenomena. While glassy structures lack obvious global symmetry breaking, local structural symmetry is a critical factor in predicting stability.
Publisher: Mineralogical Society of America
Date: 08-2017
DOI: 10.2138/AM-2017-6057
Publisher: Oxford University Press (OUP)
Date: 05-05-2020
DOI: 10.1017/S1431927620000094
Abstract: The excitability of local surface plasmon modes in radial trimers composed of gold nanorods was mapped using hyperspectral cathodoluminescence (CL) in the scanning electron microscope. In symmetric trimers, the local plasmon resonances could be excited most effectively at the ends of in idual rods. Introducing asymmetry into the structure breaks the degeneracy of the dipole modes and changes the excitability of transverse dipole modes in different directions. CL in the scanning electron microscope has great potential to interrogate in idual nanophotonic structures and is a complement to electron energy loss spectroscopy and optical microscopy.
Publisher: Elsevier BV
Date: 2015
Publisher: Wiley
Date: 18-04-2007
Publisher: IOP Publishing
Date: 27-05-2016
Publisher: American Chemical Society (ACS)
Date: 10-04-2019
Publisher: Elsevier BV
Date: 05-2004
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5TA10078J
Abstract: The photovoltaic properties of a series of EDOT-containing DPP polymers with optical band gap as low as 1.13 eV are reported.
Publisher: Wiley
Date: 02-02-2009
DOI: 10.1002/JEMT.20670
Abstract: The intermediate voltage electron microscope-tandem user facility in the Electron Microscopy Center at Argonne National Laboratory is described. The primary purpose of this facility is electron microscopy with in situ ion irradiation at controlled s le temperatures. To illustrate its capabilities and advantages a few results of two outside user projects are presented. The motion of dislocation loops formed during ion irradiation is illustrated in video data that reveals a striking reduction of motion in Fe-8%Cr over that in pure Fe. The development of extended defect structure is then shown to depend on this motion and the influence of nearby surfaces in the transmission electron microscopy thin s les. In a second project, the damage microstructure is followed to high dose (200 dpa) in an oxide dispersion strengthened ferritic alloy at 500 degrees C, and found to be qualitatively similar to that observed in the same alloy neutron irradiated at 420 degrees C.
Publisher: Elsevier BV
Date: 05-2002
Publisher: Optica Publishing Group
Date: 23-11-2020
Abstract: The optoelectronic properties of asymmetric metal nanostructures are of current interest for applications in photonics, sensing, and catalysis. Here, we break the symmetry of the localized surface plasmon resonance of gold nanorods by selective overgrowth of a single tip via a high-yield ( --> 80 % ) wet-chemical method. While optical spectroscopy exhibits a bathochromic shift of the nanoparticle plasmon resonance, cathodoluminescence and electron energy loss spectroscopy measurements reveal a breaking of the symmetry of the associated localized surface plasmon resonance mode, which results in the subwavelength concentration of electromagnetic energy. The simple, one-step postsynthetic modification allows control of nanoparticle structural parameters, and we demonstrate how the asymmetric energy redistribution leads to increases in the surface-enhanced Raman scattering of a model analyte attached to the surface of the nanostructures. The spatial localization of energy in these nanostructures may find applications in nanofocusing, nanoimaging, and light harvesting.
Start Date: 02-2019
End Date: 03-2024
Amount: $738,125.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2020
End Date: 12-2021
Amount: $1,486,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 12-2022
End Date: 04-2024
Amount: $2,020,000.00
Funder: Australian Research Council
View Funded Activity