A5022053925- Advanced Condensed Matter Physics
- Methane Hydrates and Related Phenomena
- Ferroelectric and Piezoelectric Materials
- Advanced ceramic materials synthesis
- Physics of Superconductivity and Magnetism
- MXene and MAX Phase Materials
- Microwave Dielectric Ceramics Synthesis
- Nuclear materials and radiation effects
- Magnetic and transport properties of perovskites and related materials
- Advanced materials and composites
- X-ray Diffraction in Crystallography
- Hydrocarbon exploration and reservoir analysis
- Crystal Structures and Properties
- Geomagnetism and Paleomagnetism Studies
- Intermetallics and Advanced Alloy Properties
- Ammonia Synthesis and Nitrogen Reduction
- High-pressure geophysics and materials
- Catalytic Processes in Materials Science
- Spacecraft and Cryogenic Technologies
- Luminescence Properties of Advanced Materials
- Inorganic Chemistry and Materials
- Inorganic Fluorides and Related Compounds
- Magnetic and Electromagnetic Effects
- Additive Manufacturing Materials and Processes
- Zeolite Catalysis and Synthesis
University of Tennessee at Knoxville
2015-2025
Knoxville College
2013-2024
Oak Ridge National Laboratory
2009-2023
American Society For Engineering Education
2020
Materials Processing (United States)
2018
Lawrence Livermore National Laboratory
2003
United States Geological Survey
2003
American Ceramic Society
1989-2002
University of Limerick
2002
Weizmann Institute of Science
2002
Structure I (sI) carbon dioxide (CO2) hydrate exhibits markedly different dissociation behavior from sI methane (CH4) in experiments which equilibrated samples at 0.1 MPa are heated isobarically 13 K/h 210 K through the H2O melting point (273.15 K). The CO2 release only about 3% of their gas content up to temperatures 240 K, is 22 above phase boundary. Up 20% released by 270 and remaining 271.0 ± 0.5 where sample temperature buffered until ceases. This reproducible buffering for reaction...
Even a small fraction of fine particles can have significant effect on gas production from hydrate-bearing sediments and sediment stability. Experiments were conducted to investigate the role using soil chamber that allows for application an effective stress sediment. This was instrumented monitor shear-wave velocity, temperature, pressure, volume change during CO2 hydrate formation production. The placed inside Oak Ridge National Laboratory Seafloor Process Simulator (SPS), which used...
A new phase, probably CaCuO 2 , is stable only below ∼740°C and has an orthorhombic average subcell: Cmca, a = 10.588 (1) × 10 −1 nm, b 2.8122(4) c= 6.3245(6)×10 nm. Very weak superstructure reflections indicate two distinct supercells: cell with the axis multiplied by 10, monoclinic cell, C2/c or equivalent, mon 10.946 nm∼a o−rh 6.345 nm∼c c 2.8100 12 nm 33.72 nm∼12[120] β= 105.5°. At 950°C, ternary system SrO‐CaO‐CuO extensive regions of solid solution. Complete solution observed for 2:1...
Powder diffraction pattern of SP-1 graphite has been obtained using synchrotron X-ray diffraction. Unit cell dimensions were calculated a least-squares analysis that refined to |Δ2θ°| no more than 0.007. A hexagonal was determined with space group P 6 3 / mmc (194), =2.4617(2) and c =6.7106 (4) Å. The Smith/Synder figure merit is 167 based upon 11 peaks, which indicates the quality this data set superior existing PDF card for graphite, 41-1487. It also emphasized interlayer spacing should be...
New data are presented on the phase equilibria and crystal chemistry of binary systems Sr0-Bi
Materials with the half-Heusler structure possess interesting electrical and magnetic properties, including potential for thermoelectric applications. MgAgSb is compositionally structurally related to many materials but has not been extensively studied. This work presents high-temperature x-ray diffraction analysis of between 27 420 ${}^{\ensuremath{\circ}}$C, complemented property measurements. found exist in three different crystal structures this temperature region, taking at high...
In pure zirconia, ultrafine powders are often observed to take on the high‐temperature tetragonal phase instead of “equilibrium” monoclinic phase. The present experiments and analysis show that this observation is one manifestation a much more general phenomenon in which transformation temperatures shift with crystallite/grain size. study, effect crystallite (for powders) grain solids) size → examined broadly across yttria–zirconia system. Using dilatometry differential scanning calorimetry...
Studies in the Sr‐Y‐Cu‐O and Ba‐Sr‐Y‐Cu‐O systems have revealed that Sr will substitute for Ba (Ba,Sr) 2 YCu 3 O 6+ x up to about 60%. There are no ternary compounds system equivalent three phases system. A new binary phase, “Sr 14 Cu 24 41 ”(CuO ∼ 63.158 mol%), was found which forms a solid solution with Y Sr:Y ratio of approximately 2:1. This phase can also incorporate considerable amounts Ca many other large ions.
In low purity crystals, (bottom) smaller more disordered crystallite sizes lead to increased charge trapping, compared high (top).
In this article we report on the atomic displacement parameters, lattice expansions, heat capacity, and thermal conductivity of samples Ti4AlN3 in 298–1370 K temperature range. Rietveld refinement high neutron diffraction data shows that nitrogen is substoichiometric formula Ti4AlN2.9. structure, parameters Al atoms are higher than those either Ti or N atoms. The Ti–N bonds adjacent to planes about 2.5% shorter inner layers. expansion coefficients along a c axes are, respectively,...
The spontaneous polarization (Ps) and strains (xi) in mechanically unclamped surface charge compensated PbTiO3 nanocrystals were determined as a function of particle size the range <150nm by differential scanning calorimetry x-ray powder diffraction, respectively. Significant deviations from bulk order parameters (P,xi) have been observed decreased below ∼100nm. critical (rc) which ferroelectric tetragonal phase transforms to paraelectric cubic was ∼15nm. depression transition...
The phase equilibria of the systems SrO‐CuO and SrO‐1/2Bi 2 O 3 were studied by X‐ray diffraction analysis quenched powder samples. compounds SrCuO Sr CuO melt incongruently at 1085° 1225°C, respectively. newly found compound 6 Bi 9 decomposes 965°C into SrO melts liquid 1210°C. SrBi 4 undergoes a transition ∼825°C, although both are nonstoichiometric, low‐temperature is slightly poorer in with 33.5 mol% than high‐temperature phase.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCa1-xCuO2, a NaCuO2-type related structureT. Siegrist, R. S. Roth, C. J. Rawn, and RitterCite this: Chem. Mater. 1990, 2, 192–194Publication Date (Print):March 1, 1990Publication History Published online1 May 2002Published inissue 1 March 1990https://pubs.acs.org/doi/10.1021/cm00008a022https://doi.org/10.1021/cm00008a022research-articleACS PublicationsRequest reuse permissionsArticle Views196Altmetric-Citations69LEARN ABOUT THESE METRICSArticle...