A5101651523- Fusion materials and technologies
- Microstructure and mechanical properties
- Nuclear Materials and Properties
- Chalcogenide Semiconductor Thin Films
- Ion-surface interactions and analysis
- Quantum Dots Synthesis And Properties
- Hydrogen embrittlement and corrosion behaviors in metals
- Semiconductor materials and interfaces
- Electron and X-Ray Spectroscopy Techniques
- Advanced Electron Microscopy Techniques and Applications
- Silicon and Solar Cell Technologies
- High-Velocity Impact and Material Behavior
- Nuclear materials and radiation effects
- Copper-based nanomaterials and applications
- Microstructure and Mechanical Properties of Steels
- Thin-Film Transistor Technologies
- Magnetic Properties and Applications
- Semiconductor materials and devices
- nanoparticles nucleation surface interactions
- Physics of Superconductivity and Magnetism
- Metallurgy and Material Forming
- Housing, Finance, and Neoliberalism
- Semiconductor Quantum Structures and Devices
- Intermetallics and Advanced Alloy Properties
- Non-Destructive Testing Techniques
University of Oxford
1982-2020
University of Illinois Urbana-Champaign
1996-2012
Moreland City Council
2011
University of Illinois System
2004-2010
Defence Science and Technology Group
1994
The immutable refrain ‘change is the only constant’ serves as both cautionary and aspirational catchphrase. Our social environment changing; improving on average globally, but with benefits dist...
An enhancement in ${\mathit{J}}_{\mathit{c}}$ of ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathit{x}}$ single crystals a magnetic field is observed after irradiation with 1-MeV electrons. Typically, factor-of-2 increase deduced from hysteresis loops at 10 K and 1 T H\ensuremath{\parallel}c. This about 1/2 that produced by proton neutron irradiations under similar measurement conditions. In situ transmission-electron-microscopy studies found no visible...
Compact city policies such as Melbourne 2030 have been established in Australia for a range of reasons including climate change. It is now clear that the policy has not effective—with new development mostly on urban fringe. This failure often sheeted home to resident and local government resistance densification. article suggests this narrative insufficient explain at metropolitan-wide scale clearly mistaken one suburb, where aspects planning system appear thwart aims strategic by...
A microchemical analysis study is reported comparing the grain and boundary chemistries of Cu(In,Ga)Se2 (CIGS) films deposited by three different laboratories processes. An a GaAs wafer described to provide calibration accuracy precision energy dispersive spectroscopy nanoprobe as applied in current instruments. When averaged over many measurements instrument ±0.1at.% ±1.0at.% for individual points. The CIGS shows less than 0.5at.% composition difference each constituent element between...
The spontaneous formation of voids has been observed in Cu(In,Ga)Se2 films deposited by multistage evaporation processes but was not found commonly single-stage evaporated material. These may be isolated the grains or occur at grain boundaries. exhibit strongly faceted geometries with interior surfaces being close-packed {112} planes chalcopyrite structure. A model based on Kirkendal effect [Trans. AIME 171, 130 (1947)] and interdiffusion phase reaction bilayer process is proposed to explain...
Plane-view and cross-sectional transmission electron microscopy have been used to examine the structure of epitaxial metastable zinc-blende (GaAs${)}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$(${\mathrm{Ge}}_{2}$${)}_{\mathrm{x}}$ alloys grown by rf sputter deposition on GaAs(001) substrates. An analysis bright-field dark-field images obtained from both fundamental superstructure reflections showed, in addition (111) microtwins (a/2)〈110〉 line dislocations, existence ordered antiphase regions....
Complete Cu(In,Ga)Se2 (CIGS) solar cells in which the collecting heterojunctions were formed by chemical bath deposition of CdS analyzed transmission electron microscopy and energy dispersive spectroscopy. The CIGS was produced at 400 or 580 °C as either single layers a two-step bilayer process. compositions grain boundaries found to be same grains before except low temperature-deposited but after anion deficient with some evidence Cu loss from residual most cases. results are consistent...
Cu ( In 1 − x Ga ) Se 2 (CIGS) films were grown on (001) GaAs at 570 or 500°C by means of metal organic vapor-phase epitaxy. All Cu-rich [Cu∕(In+Ga)>1] with pseudomorphic Cu2Se second phase particles found only the growth surface. During growth, diffusion from substrate and vacancies generated formation CIGS surface occurred. The processes lead to Kirkendall voids GaAs/CIGS interface. Transmission electron microscopy nanoprobe energy dispersive spectroscopy used analyze void...
Epitaxial zinc blende structure metastable (GaAs)1−x(Si2)x alloys have been grown with 0<x<0.3 on As-stabilized GaAs(100) substrates by a hybrid sputter deposition/evaporation technique. The films, typically 2–3 μm thick, were deposited at 570 °C growth rates between 0.7 and 1 h−1. Alloys 0<x<0.12 defect-free as judged plan-view cross-sectional transmission electron microscopy (TEM XTEM) x-ray diffraction peak widths approximately the same that of substrate, 30...
To determine the influence of interface type on accumulation damage and ion mixing in GaAs/AlxGa1−xAs heterostructures, produced by implantation at 77 K single-layer (GaAs/AlxGa1−xAs/GaAs) double-layer (GaAs/AlxGa1−xAs/GaAs/ AlxGa1−xAs/GaAs) heterostructures has been investigated using a combination Rutherford backscattering spectrometry transmission electron microscopy. In geometry, degree disorder increases with depth is greater AlxGa1−xAs GaAs than one. The distribution sample geometry...
Abstract The microstructural changes brought about by irradiating α-iron containing a distribution of platelet α″-nitrate precipitates with fast neutrons at 355 K are described. With increasing irradiation dose these underwent radiation-induced dissolution. By 4 × 1022 m-2(E> 1 MeV) many had been replaced rafts small apparently lying within the pre-irradiation boundaries original precipitates. Others were unaffected, while number partially dissolved and appeared as regions undisturbed...
Thermal annealing, irradiation with electrons (25-300 keV), and photons (hν = 2.33-3.88 eV) have been used to stimulate the crystallization of isolated amorphous zones in Si, Ge, GaAs, GaP InP. Transmission electron microscopy computer image analysis were determine processes. For all materials, thermally stimulated occurred only at temperatures above 373 K. The electron-stimulated rate is sensitive energy. Initially, decreases increasing energy until it reaches a minimum about one half...
The effects of hydrogen on the fracture metals will be reviewed using a selection observations based use in situ environmental cell experiments. These were developed to allow understanding mechanisms failure process. technique, combined with cell, is well suited mechanistic studies as it allows observation crack tip processes at high resolution and relatively fugacity aggressive environment. methods have been applied behavior several systems. Selected examples discussed general pattern...
The magnetomechanical effect for a quenched and tempered alloy steel has been studied. In most published work it found that stress causes the magnetization to move toward anhysteretic magnetization. However, in present was under special conditions moves away from when cyclic is applied. This behavior tentatively explained by applying Preisach model of ferromagnetic hysteresis.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.