A5018622119- Intermetallics and Advanced Alloy Properties
- Advanced materials and composites
- Advanced ceramic materials synthesis
- Energetic Materials and Combustion
- MXene and MAX Phase Materials
- Semiconductor materials and interfaces
- Metal and Thin Film Mechanics
- nanoparticles nucleation surface interactions
- Thermal and Kinetic Analysis
- Aluminum Alloys Composites Properties
- Advancements in Solid Oxide Fuel Cells
- Electronic and Structural Properties of Oxides
- Boron and Carbon Nanomaterials Research
- Chemical Thermodynamics and Molecular Structure
- Crystallization and Solubility Studies
- Electromagnetic Effects on Materials
- Powder Metallurgy Techniques and Materials
- Advanced Thermoelectric Materials and Devices
- Catalytic Processes in Materials Science
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Nuclear materials and radiation effects
- Electronic Packaging and Soldering Technologies
- Injection Molding Process and Properties
- Metallurgical Processes and Thermodynamics
University of California, Davis
2012-2023
University of the Punjab
2023
University of Okara
2023
University of California System
1975-2016
American Ceramic Society
1996-2010
Lawrence Livermore National Laboratory
1975-2010
Life Cycle Engineering (United States)
2010
University of Pavia
1997-2008
National Interuniversity Consortium of Materials Science and Technology
2006
United States Naval Research Laboratory
1983
Abstract Transparent samples of cubic (8 mol % yttria) and tetragonal (3 zirconia were prepared from nanometric powders by the pulsed electric current sintering process. The crystallite size resulting dense was about 50 nm in both cases. consolidation pressure had a positive effect on occurrence transparency for modifications. Transmittance near infrared 1 mm thick is above 60 %YSZ) YSZ) zirconia, representing between 70 80 theoretical values two Samples yellowish‐brown coloration which...
The effect of the application a dc current on annealing point defects in Ni3Ti was investigated by positron annihilation spectroscopy. An increased defect rate observed under influence and attributed to 24% decrease activation energy mobility. results are interpreted terms electron wind complex nature diffusion ordered intermetallic phases. They provide direct evidence for an increase mobility intermetallics current.
A kinetic model for the reduction in specific surface area during isothermal sintering is examined detail. Experimental data a variety of materials including A1 2 O 3 , B, Ni, Cu, ZnO, TiO Fe and As‐Se‐S glasses are analyzed by technique provided. The results this agree well with those previously identified mechanisms each material. based on driven curvature gradient interparticle neck region associated initial‐stage sintering. At intermediate stage sintering, diminished shifts driving force...
The transport of oxygen in dense samples yttria-stabilized zirconia (YSZ), average grain size d approximately 50 nm, has been studied by means 18O/16O exchange annealing and secondary ion mass spectrometry (SIMS). Oxygen diffusion coefficients (D*) surface (k*) were measured for temperatures 673<or=T/K<or=973 at an partial pressure 900 mbar. No evidence is found fast along boundaries. Rather, the analysis indicates that boundaries hinder transport.
Gallium nitride was found to sublime congruently from a torsion—effusion cell when the ratio of orifice area sample about 1/30 and incongruently yield nitrogen gas liquid gallium this 1/100 or less. A mass-spectrometer investigation revealed no measurable concentrations vapor molecules. The heat activation for reaction 2GaN(s)=2Ga(1)+N2(g) calculated be 39 kcal at 1300°K temperature dependence effusion data. rate 2GaN(s)=2Ga(g)+N2(g) measured by torsion—Langmuir method. From sublimation...
This research demonstrates protonic conductivity in nanoscale fluorite- structured oxides as well YSZ at low temperatures. The photograph shows a water concentration cell of dense nanostructured (grain size ∼ 20 nm) Sm-doped ceria ceramic operating room temperature. One side (cathode) the is exposed to wet-air while other (anode) immersed into de-ionized water. current measured from 30 nA.
In this communication we elucidate a microstructural picture of proton conduction in nano-crystalline yttria-stabilized zirconia at low temperatures (Kim et al. Adv. Mater., 2008, 20, 556). Based on careful analysis electrical impedance spectra obtained from samples with grain sizes ∼13 and ∼100 nm under both wet dry atmospheres over wide range (room temperature–500 °C), were able to identify the pathway for material. It was found that boundaries are highly selective ion transport, being...