A5017339266- Chalcogenide Semiconductor Thin Films
- Advanced Semiconductor Detectors and Materials
- Quantum Dots Synthesis And Properties
- X-ray Diffraction in Crystallography
- High-pressure geophysics and materials
- Semiconductor Quantum Structures and Devices
- nanoparticles nucleation surface interactions
- Advanced ceramic materials synthesis
- Glass properties and applications
- Phase-change materials and chalcogenides
- Solid State Laser Technologies
- Solidification and crystal growth phenomena
- Optical properties and cooling technologies in crystalline materials
- Boron and Carbon Nanomaterials Research
- Advanced materials and composites
- Gas Dynamics and Kinetic Theory
- Diamond and Carbon-based Materials Research
- Luminescence Properties of Advanced Materials
- Advanced Thermoelectric Materials and Devices
- Crystallization and Solubility Studies
- Semiconductor materials and interfaces
- Solid-state spectroscopy and crystallography
- Crystal Structures and Properties
- Photorefractive and Nonlinear Optics
- Rocket and propulsion systems research
Brimrose (United States)
2010-2024
The University of Texas at Austin
2018
Center for High Pressure Science and Technology Advanced Research
2018
United States Department of the Army
2018
Indian Institute of Science Bangalore
2018
United States Army Combat Capabilities Development Command
2018
United States Army
2018
BAE Systems (United States)
2003-2007
Marshall Space Flight Center
1997-2006
Institute of High Pressure Physics
2004
Abstract Fundamental limitations, with respect to nanocrystalline materials, of the traditional elaboration powder diffraction data like Rietveld method are discussed. A tentative analysis patterns nanocrystals based on examination variation lattice parameters calculated from individual Bragg lines (named “ apparent parameter ”, alp ) is introduced. We examine application our methodology using theoretical computed for models a perfect crystal and grains two-phase, core-shell structure. use...
Application of in situ high pressure powder diffraction technique for examination specific structural properties nanocrystals based on the experimental data SiC nanocrystalline powders 2 to 30 nrn diameter is presented. Limitations and capabilities techniques themselves methods elaboration applied with very small dimensions (< nm) are discussed. It shown that due complex structure, constituting a two-phase, core/surface shell system, no unique lattice parameter value and, consequently,...
Based on t heoret ical calculatio ns of p ow der di˜raction data it is show n that the assumption inÙni te crystal lattice for small particles not j ustiÙed , leads to signiÙcant changes patterns, and may lead erroneous interpretation exp erimental results .A alternate ev aluation di˜ractio nanoparticle s, based so-called \apparent parameter ", a l prop osed.PAC S numb ers: 61.46.+ w I r o d u ct io nThe crysta structure m ateri als i s determ ned by combi e˜ect ong -ra ng e forces rrespecti...
In this review work we discuss applicability of Bragg scattering to examination nanocrystals. We approximate the structure nanograins by a commonly accepted core-shell model. show that, for principal reasons, equation is not applicable directly use relation through application apparent lattice parameter (alp) concept which evaluate quantitatively also introduce new structure, Equivalent Cubic Lattice Parameter (EClp), quantifies deviation real (trigonal) from its parent fcc due deformation (...
Abstract The applicability of standard methods for the evaluation powder diffraction data nano-size crystallites is analyzed. Based on theoretical considerations, it shown that deviations structure small particles from Bragg approximation an infinite crystal lattice leads to significant differences in patterns, which may lead erroneous interpretation experimental results. An alternative nano-particles, based so-called "apparent parameter", alp , proposed. this method, real nano-crystals...
A comprehensive experimental study on the antiferromagnetic interlayer exchange coupling in high quality epitaxial all-semiconducting $\mathrm{EuS}∕\mathrm{PbS}∕\mathrm{EuS}$ trilayers is reported. The influence of substrates, thickness nonmagnetic $\mathrm{PbS}$ spacer layer, and temperature was investigated by means SQUID magnetometry. In with a between 4 $12\phantom{\rule{0.3em}{0ex}}\AA{}$ low hysteresis loops showed signature coupling. value energy determined simulating data based...
Topological insulators have been the subject of intense research interest due to their unique surface states that are topologically protected against scattering or defects. However, relationship between crystal structure and topological insulator state remains be clarified. Here, we show effects hydrostatic pressure on structural, vibrational, properties Bi1.5Sb0.5Te1.8Se1.2 up 45 GPa using X-ray diffraction Raman spectroscopy in a diamond anvil cell, together with first-principles...
A comparative study was conducted to investigate the 3.9 µm mid-IR emission properties of Ho 3+ doped NaYF 4 and CsCdCl 3 crystals as well Ga 2 Ge 5 S 13 glass. Following optical excitation at ∼890 nm, all studied materials exhibited broad emissions centered ∼3.9 room temperature. The µm, originating from I → 6 transition, showed long lifetime values ∼16.5 ms ∼1.61 for crystal glass, respectively. Conversely, a relatively short ∼120 µs. Temperature dependent decay time measurements were...
Large crystals of Hg<sub>2</sub>Cl<sub>2</sub> and Hg<sub>2</sub>Br<sub>2</sub> (48 mm in diameter, up to 600g weight) have been grown by self-seeded contactless Physical Vapor Transport (PVT) technique closed ampoules vertical configuration. Seed selection was accomplished the small diameter tubing at ampoule tip. Material purification done resublimation processing. The show high transparency, with good transmittance crystallographic quality. An acousto-optic modulator built from crystal...
Although the density of dislocations is used as an indicator quality semiconductor wafers, it also necessary to provide a description dislocation distribution for those materials prone polygonization (namely formation sub-grain boundaries). In this work shown that visual inspection etch pit distributions insufficient and quantitative comparison with random more informative. This was achieved in two ways: (i) by Poisson (ii) using normalized radial plots, former yielding type latter...