This study was to investigate unusual phase transitions driven by electron correlation effects that occur in many f-band transition metals and are often accompanied by large volume changes: approx. 20% at the sigma-a transition in Pu and 5-15% for analogo...
National Technical Information Service (NTIS)
A new high pressure combustion facility was built to investigate mixing in axisymmetric, turbulent jets exiting into quiescent reservoirs. The facility uses fluorine and nitric oxide, diluted with nitrogen, for chemical product formation that is accompani...
The high pressure behavior of low-Z materials is of interest because of their abundance in the universe and importance to geophysics and planetary physics -- in particular hydrogen compounds which form the centers of the giant planets. In general, these lightweight molecular systems appear to transform under pressure to extended nonmolecular ...
NASA Astrophysics Data System (ADS)
... Title : High Pressure Phase Transformations in Turbostratic Boron Nitride Using Magnesium Boron Nitride as the Catalyst. ...
DTIC Science & Technology
... Descriptors : *HIGH PRESSURE, *PHASE STUDIES, ANTIMONY COMPOUNDS, BARIUM COMPOUNDS, BERYLLIUM COMPOUNDS, BORON ...
High pressure and low temperature experiments with CO2 hydrate were performed using diamond anvil cells and a helium-refrigeration cryostat in the pressure and temperature range of 0.2-3.0 GPa and 280-80 K, respectively. In situ x-ray diffractometry revealed that the phase boundary between CO2 hydrate and water+CO2 extended below the ...
Progress is reported on a project to determine the properties and boundaries of high pressure phases
NASA Technical Reports Server (NTRS)
... TURBINES, *RANKINE CYCLE, *POWER ENGINEERING, SPACECRAFT, RADIATIVE TRANSFER, HIGH PRESSURE, VAPOR PHASES, KINETIC ...
Phase diagrams of refractory metals remain essentially unknown. Moreover, there is an ongoing controversy over the high pressure (P) melting temperatures of these metals: results of diamond anvil cell (DAC) and shock wave experiments differ by at least a factor of two. From an extensive ab initio study on tantalum we discovered that ...
Energy Citations Database
The density functional calculations of the energy band structure and density of state for the tetragonal PbO-type phase ?-FeSe and hexagonal NiAs-type phase ?-FeSe are reported in this paper. The structural phase transition from tetragonal to hexagonal FeSe under high pressure is investigated, ...
High-pressure studies have been performed on heavy rare earth metals Terbium (Tb) to 155 GPa and Holmium (Ho) to 134 GPa in a diamond anvil cell at room temperature. The following crystal structure sequence was observed in both metals hcp {yields} Sm-type {yields} dhcp {yields} distorted fcc (hR-24) {yields} monoclinic (C2/m) with increasing pressure. The last transformation ...
... Title : ATTENUATION AND PHASE VELOCITY SPECTRA IN SEDIMENTARY ROCKS UNDER HIGH PRESSURE. Corporate Author : ...
Constant-pressure first-principles molecular-dynamics simulations were carried out to study structural and electronic properties of the polymeric phase of liquid phosphorus at high pressures. It is found that, around 1 GPa, atoms are connected by covalent bonds by p electrons and accompany a Peierls distortion as ...
A newly developed high-pressure microbalance was used to monitor the hydriding-dehydriding kinetics of SmCo/sub 5/ at room temperature. The rate behavior of the alpha-beta phase hydride transformation was found to have a t/sup 2/ time dependence. The authors have developed a high-pressure hydrogen microbalance which is capable of responding to the rapid ...
... from High-pressure ... Raman characterization of the semi-transparent recovered sample indicates similarities with the high pressure phase. ...
The authors report about the shock-compression response of highly porous (55% and 65% dense) mixtures of 4Al + 3SiO{sub 2} powders having shock-induced phase transitions and chemical reactions. Shock recovery experiments were performed using the CETR/Sawaoka plate-impact system (P = 40 to 100 GPa) and the Sandia Momma Bear A Comp B fixture (P = 22 to 45 GPa). The recovered ...
DOE Information Bridge
Supercritical fluid extraction has been proven as an efficient separation method for some specific industrial applications. The knowledge of the phase behavior of supercritical systems plays an important role in the process design. High pressure vapor-liquid phase equilibrium compositions were measured for the ...
In situ Raman spectroscopy and synchrotron X-ray diffraction (XRD) experiments have been performed to investigate the response of guanidinium perchlorate (C(NH2)3+�ClO4-, GP) to high pressures of ~11 GPa. GP exhibits a typical supramolecular structure of two-dimensional (2D) hydrogen-bonded ionic networks at ambient conditions. A subtle ...
PubMed
Zero pressure densities of rock Hugoniots in high pressure phases compared with phase transitions of
Silver azide (AgN3) was compressed up to 51.3 GPa. The results reveal a reversible second-order orthorhombic-to-tetragonal phase transformation starting from ambient pressure and completing at 2.7 GPa. The phase transition is accompanied by a proximity of cell parameters a and b, a 3� rotation of azide anions, and a change of ...
... Metallography, Superconductors, Band theory of solids, Thermodynamics, Complex compounds, High pressure, Radiation effects, Phase ...
... LIQUIDS, MASS, SPECTROMETRY, HIGH PRESSURE, PHASE, TIME, IDENTIFICATION, CORRELATION, LIQUID CHROMATOGRAPHY, ...
... The second phase of the program was concerned with the mechanism of densification of hafnium diboride in high pressure hot pressing. ...
... COMPOUNDS, CARBONATES, DIOXIDES, HIGH PRESSURE, LEAD COMPOUNDS, CRYOGENICS, NIOBIUM COMPOUNDS, OXIDES, PHASE ...
... Title : DETERMINATION OF STABILITY PARAMETERS FOR TWO PHASE NATURAL CIRCULATION HYDRAULIC LOOPS AT HIGH PRESSURE. ...
The equations of state and phase diagrams of the cubic spinel and two high-pressure polymorphs of MgAl2O4 have been investigated up to 65 GPa using density functional theory, the space-filling polyhedral partition of the unit cell, and the static approximation. Energy-volume curves have been obtained for the spinel phase, the recently ...
The report contains data on synthesis of new materials under high pressure resulting from a change in the electron structure of the atoms.
The construction of the high pressure gas phase fermentation system has been completed. Photographs of the various components of the system are presented, along with an operating procedure for the equipment.
... The high pressure experiments were performed in diamond anvil cells ... High pressure phase appears near 9 GPa in both x-ray diffraction and ...
The report finalizes two phases of a broad study whose general purpose is to elucidate hazards to personnel arising from aerosols in high pressure helium-oxygen atmospheres. Studies have been completed on the generation of aerosols within high pressure en...
We report on the synthesis of superconducting single crystals of FeSe and their characterization by x-ray diffraction, magnetization and resistivity. We have performed ac susceptibility measurements under high pressure in a hydrostatic liquid argon medium up to 14�GPa and we find that T(C) increases up to 33-36�K in all samples, but with slightly ...
High-pressure phase transition and electronic structure of Zn{1-x}Mn{x}Se (x = 0 and 0.25) were calculated by using a first-principles method based on density functional theory. Zn{0.75}Mn{0.25}Se was found to be antiferromagnetic in both normal and high pressure states. Our calculated values of critical pressures ...
Phase diagrams of refractory metals remain essentially unknown. Moreover, there is an ongoing controversy over the high-pressure melting temperatures of these metals: results of diamond anvil cell (DAC) and shock wave experiments differ by at least a factor of 2. From an extensive ab initio study on tantalum we discovered that the body-centered cubic ...
Phase diagrams of refractory metals remain essentially unknown. Moreover, there is an ongoing controversy over the high-pressure melting temperatures of these metals: results of diamond anvil cell (DAC) and shock wave experiments differ by at least a factor of 2. From an extensive ab�initio study on tantalum we discovered that the body-centered cubic ...
... atmosphere thermodynamic data with high pressure observations could lead to a greater understanding of phase transformations and equilibria in ...
... CRYSTAL STRUCTURE, DYNAMICS, PHASE TRANSFORMATIONS, STRUCTURAL PROPERTIES, EDGES, HIGH PRESSURE, X RAYS ...
High pressure and low temperature experiments with CO(2) hydrate were performed using diamond anvil cells and a helium-refrigeration cryostat in the pressure and temperature range of 0.2-3.0 GPa and 280-80 K, respectively. In situ x-ray diffractometry revealed that the phase boundary between CO(2) hydrate and water+CO(2) extended below ...
We present direct observation of the magnetic state in a ?(fcc)-Co high-pressure phase accompanied by the ??? (hcp ? fcc) transition by means of Co K-edge x-ray magnetic circular dichroism up to 170 GPa. In contrast to the prediction made in previous studies that ?(fcc)-Co is nonmagnetic, this study concludes that ?(fcc)-Co is ...
We have computed the melting line of lithium hydride up to 200GPa using the two-phase simulation technique coupled with first-principles molecular dynamics. Our predicted melting temperature at high pressures varies slowly with compression, ranging from 2000 to 2450K at 50 200GPa pressures. The compressed fluid close to the melting ...
Structural phase transitions in the rare-earth metal Dysprosium have been studied in a Diamond Anvil Cell (DAC) to 119 GPa by x-ray diffraction. Four transformations following the sequence hcp {yields} Sm-type {yields} dhcp {yields} hR24 (hexagonal) {yields} bcm (monoclinic) are observed at 6, 15, 43, and 73 GPa respectively. The hexagonal to monoclinic transformation is ...
... 2 O 3 Phase Under High Pressure Center for Nanomaterials Research ... 2 Formation of An Oxygen-Deficient Y 2 O 3 Phase Under High Pressure ...
The phase relations of some mixtures of ammonia and water are investigated to create a phase diagram
This Letter describes neutron diffraction measurements of the rocksalt structured phase of AgI at high pressure and temperature and the structural disorder which accompanies its high conductivity. In contrast to the first-order structural phase transition which results in fast-ionic ?-AgI at ...
The structural characteristics of Sm{sub 2}Zr{sub 2}O{sub 7}, an ordered pyrochlore, were studied by angle-dispersive X-ray diffraction (XRD) and Raman scattering methods with increasing pressure. A structural distortion was observed at low pressures; but the distortion disappeared at pressures above 13.5 GPa. Above 18 GPa, the pyrochlore structure is unstable and a pressure-induced ...
Evidence for a structural phase transition from rutile {alpha}-CrO{sub 2} phase I (P4{sub 2}/mnm) to orthorhombic {beta}-CrO{sub 2} phase II (CaCl{sub 2}-like, Pnnm) is presented using angle-resolved synchrotron x-ray diffraction and high sensitivity confocal Raman spectroscopy. The transition to the CaCl{sub 2} structure, which ...
General relationships are discussed for phase formation in B group element alloys with increasing pressure. The main tendency is determined by the homology rule: the effect of pressure is to change the phase equilibria in the same way as when one component is replaced by a heavier element in the same group. The sequence of relative configurations of ...
Recently, high pressure treatments such as hot isostatic pressing have become more familiar in industrial processes. The high pressure induces changes of both the phase equilibrium and the kinetics of the phase transformation in alloys. The iron-rich ...
A high-pressure M�ssbauer spectrometer for the 93.3-keV resonance in67Zn and an X-ray diffractometer of the Guinier type are used to investigate67ZnSe powder at high external pressures. At � 13 GPa, a phase transition from the zinc blende to the fcc (NaCl) structure is observed. The transition is accompanied by a 15.2% decrease of the volume of the ...
Two high-pressure phase transitions in GeO2 have been discovered through first-principles computer simulations: the first is a transition from the pyrite-type (FeS2) to cotunnite-type (?-PbCl2) structure predicted to occur at a pressure of �300 GPa, and the second is a transition from the cotunnite-type to the hexagonal Fe2P-type structure at �600 GPa. ...
Strain-induced phase transformations (PTs) under high-pressure differ fundamentally from the pressure-induced PTs under quasihydrostatic conditions. A model and finite-element approach to strain-induced PTs under compression and torsion of a sample in rotational diamond anvil cell are developed. The current paper is devoted to the numerical study of ...
Despite the great technological and scientific importance of graphite and diamond, the carbon phase diagram is poorly understood. Developed here is a simple theoretical model for the prediction of this diagram at very high pressures. The diamond melting c...
A process for development of the pilot type high temperature high pressure solenoid valve used in a PWR power plant is described. The whole development process might be divided into two phases: research design and improvement. In the former phase the ques...
The high pressure phase transitions, the equation of state and associated volume collapses of IV - VI compound semiconductors have been analysed by means of a three-body potential (TBP) model approach. The charge-transfer effects, arising from the overlap...
The magnetic susceptibility of SmS indicates a discontinuous and hysteretic magnetic transition at 6 kbar. The ground state of the 4f shell in the metallic high-pressure 'collapsed' phase is nonmagnetic, contrary to Hund's rules. Nonmagnetic behavior of t...
Mar 7, 2006 ... High-pressure phases of ice are major components of the giant icy ... The new research reveals in one of the high-pressure phases of ice ...
NASA Website
This report describes the development of a high-frequency ultrasonic measurement capability for application to the study of phase transitions at elevated pressure and temperature. We combined expertise in various aspects of static high-pressure technique ...
A systematic study was made on polyethylene at high pressures and elevated temperatures using X-ray diffraction. Polyethylene with an initial chain-folded morphology and the orthorhombic crystal structure did not transform to any other phase before meltin...
This study attempts to evaluate the solubility of carbon in metallic phases at high pressure and high temperature thanks to a nuclear microprobe. We will present our first results and their applications to the planetary cores.
The impact cratering process may be divided into three stages, including a short high pressure phase
... BORON COMPOUNDS, *ANTIMONY ALLOYS, CRYSTAL STRUCTURE, SYNTHESIS(CHEMISTRY), HIGH PRESSURE, PHASE STUDIES ...
... HIGH PRESSURE, PIEZOELECTRIC CRYSTALS, STANDARDS, QUARTZ RESONATORS, CRYSTAL OVENS, CRYSTAL OSCILLATORS, PHASE ...
... cooling system involving two moving boundaries is formulated. ... HIGH PRESSURE, HIGH TEMPERATURE, BOUNDARY LAYER, PHASE STUDIES ...
Abstract: The high pressure phase transition of cinnabar (alpha-HgS) was studied by ... The cinnabar crystal structure was found to transform to the . ...
... HIGH PRESSURE, *ROCKET NOZZLES, *ROCKET PROPELLANTS ... OXIDES, HETEROGENEOUS REACTORS, NOZZLE THROATS, PHASE ...
... HIGH TEMPERATURE, THIN FILMS, CHARGE CARRIERS, EPITAXIAL GROWTH, HIGH PRESSURE, VAPOR PHASES, NITRIDES, NITROGEN ...
... conditions. A reversible solid-state phase transformation was observed between the orthorhombic and hexagonal phases. None ...
The crystal and magnetic structures of the manganites Pr1-xSrxMnO3 (x = 0.5, 0.56) have been studied by means of powder neutron diffraction at high external pressures up to 4.8 GPa. At ambient pressure both Pr0.44Sr0.56MnO3 and Pr0.5Sr0.5MnO3 have a tetragonal structure (space group I4/mcm). At T_{{\\mathrm {N}}} \\approx 215 K in Pr0.44Sr0.56MnO3 the onset of A-type antiferromagnetic (AFM) state ...
., Filinchuk Y.,Chernyshov D., Dmitriev V. (2008). Synthesis of an orthorhombic high pressure boron phase. Sci-90-481-9817-7 #12;Author's personal copy 207 BORON UNDER PRESSURE: PHASE DIAGRAM AND NOVEL HIGH-PRESSURE PHASE ARTEM R of this element, and recent surprises found ...
E-print Network
Polychlorinated dibenzodioxins (PCDD) and polychlorinated dibenzofurans (PCDF) are present with several hundred organic compounds in raw fly ash extract. A first-step normal-phase semipreparative high-pressure liquid chromatography (HPLC) fractionation with a three-solvent gradient elution program separates PCDD and PCDF into a single fraction with about ...
We have determined infrared reflectivity of potassium dihydrogen phosphate (KDP) in the paraelectric (T>Tc=135 K) and ferroelectric phase (Tphase is suppressed by pressure, we track ...
In situ high-pressure x-ray and neutron powder diffraction experiments on the recently reported metastable high-pressure polymorph of Bi2O3 (HP-Bi2O3) at ambient temperature has revealed a first-order translationengleiche subgroup-supergroup phase transition at a pressure of ~2.1 GPa from P31c toward space group P63mc (No. 186). ...
An attempt was made to correlate the information obtained from high pressure studies of phase equilibria in metals with one atmosphere thermodynamic data. Both one- and two-component metallic systems were studied. It was found that in most cases, quantitative thermodynamic predictions at a level of accuracy and reliability ...
We performed the single-crystal X-ray diffraction study of a perovskite-type gold mixed-valence compound, Cs{sub 2}Au{sup I}Au{sup III}Cl{sub 6}, under high pressures up to 18 GPa by using a diamond-anvil-cell with helium gas as an ideal hydrostatic pressure-transmitting medium. The lattice parameters and the variable atomic positional parameters were ...
We report infrared (IR) spectroscopic measurements of carbon monoxide (CO) at high pressures. Although CO is one of the simplest heteronuclear diatomic molecules, it displays surprisingly complex behavior at high pressures and has been the subject of several studies [1-5]. IR spectroscopic studies of ...
for the global water cycle related to the occurrence of the 10 � phase at high pressure, its structural diffractometry on samples synthesised at high pressure. A water content of 2 molecules per formula unit has been. This is reflected in the steeper pressure�volume slopes of the equation ...
Recent experiments demonstrate that high pressure is a powerful tool for the synthesis of new unusual inorganic polymers consisting of low-Z elements. However, experience within organic chemistry, for example, polyethylene, provides evidence that polymeric phases with high thermal stability can be potentially synthesised by ...
The work was divided between two aspects of high pressure hot pressing. The first phase involved a study of the problems associated with fabricating crack free compacts of TiB2 by high pressure hot pressing. In addition, the bend strength and fracture mod...
The garnet structure type is of fundamental importance in Earth [1] and materials science. High-pressure investigations of oxide garnets composed of transition and rare earth elements have revealed a range of interesting phenomena including pressure-induced amorphization, phase transitions, magnetic collapse, and potential transformation to superhard ...
A phenomological analysis and correlation of available volumetric and entropy data was performed for III-V compounds. The results of these procedures were used in the design of high pressure synthesis experiments to attempt to stabilize and retain the com...
The melting relations and distribution of K and Cs in portions of the system was determined at high pressures. Ferrosilite is stable as a primary phase at high pressures because of the incongruent melting of ferrosilite to quartz plus liquid and the bound...
This investigation was a study of inorganic chemical reactions and phase equilibria under high pressures and concomitant high temperatures. It consisted of two parts. The first was the study of the pressure-temperature dependence of oxidation-reduction re...
A method for predicting a priori the conditions for indirect diamond synthesis, i.e., synthesis via a metal 'catalyst' or solvent, was developed. The method is based upon thermodynamic calculation of the high pressure phase equilibria for a given metal-ca...
An investigation into the high-pressure behavior of AX2-type iron pnictides was conducted using first-principles calculations based on density functional theory within the generalized gradient approximation. Our results demonstrate that a phase transition from the marcasite to the CuAl2 occurs at 108 GPa for FeP2, at 92 GPa for FeAs2, and at 38 GPa for FeSb2, ...
An investigation into the high-pressure behavior of AX(2)-type iron pnictides was conducted using first-principles calculations based on density functional theory within the generalized gradient approximation. Our results demonstrate that a phase transition from the marcasite to the CuAl(2) occurs at 108�GPa for FeP(2), at 92�GPa for FeAs(2), and at 38�GPa for FeSb(2), ...
Three-Dimensional, Three-Phase Combustion Optional Powerpoint file. ACCOMPLISHMENTS. Code describes high-pressure homogeneous and heterogeneous spray ...
A 48-microphone planar phased array system was used to acquire noise source ... High-pressure spool shaft rotation frequency grid point location ...
... oINFRARED SYSTEMS Phase 1 - Germanium D Jerry D.Stachiw ... Thermal imagers Polycrystalline germanium Laser windows Infrared systems . . ...
... Phase 1. Germanium. ... Germanium also exhibits static fatigue under sustained flexure loading in the marine environment. ...
... PHASE TRANSFORMATIONS, *PALLADIUM ALLOYS, *PLATINUM ALLOYS, *RHODIUM ALLOYS, *SELENIUM ALLOYS, REPRINTS, CRYSTAL ...
... discussion), the crystal structure corresponds to the close ... these structures are monoclinic, space group P21/m ... phase α and high-pressure phase β of ...
... The a-quartz particles on exposure to either continuous high-pressure phases of silica and boron nitride. Fedoseev et wave ...
... Title : Amorphous Phase Separation, Salt Precipitation, and High Pressure Effects in PPO (Poly(propylene oxide))Containing NaI. ...
A broadband spectroscopy method is proposed to measure the ultrasonic wave phase velocity of Z-cut quartz under high pressure up to 4.7 GPa. The sample is in a hydrostatic circumstance under high pressure, and we can get longitudinal wave and shear wave signals simultaneously in our work. By ...
Raman spectra of La(0.75)Ca(0.25)MnO(3) have been collected for the first time over a wide pressure range (0-14 GPa) using a diamond anvil cell. The frequency range explored (200-1100 cm(-1)) and the very good quality of the data allowed us to carefully analyze the pressure evolution of the phonon modes of the MnO(6) octahedra. The results show an abrupt transition at approximately 7.5 GPa with an ...
High pressure product fluid from a petroleum well goes into a high pressure separation vessel where preliminary phase separation of the constituents takes place. Oil and gas leave the preliminary separator by a flow line. Power fluid for a triplex pump flows from the high ...
Germanium (Ge) is an important semiconductor and analog material for Silicon. Crystalline Ge undergoes a series of pressure-induced transitions, including metallization and electronic changes [2], and a series of structural changes measured by XRD. The first phase transition of crystalline Ge from a diamond to ?-Sn structure, which is accompanied by ...
The pressure dependence of the stereochemical course in hot homolytic T- for-H and /sup 38/Cl-for-Cl substitution in meso and racemic 1,2-dichloro-1,2- difluoroethane has been studied from about 10 to 10/sup 4/ torr. For both recoil tritium and chlorine, substitution with inversion of configuration is almost negligible in the gas phase and its yields remain constant ...
We performed powder x-ray experiments on hydrogen sulfide ( H2 S ) under high pressure at room and low temperatures. Phase V appearing above 27 GPa at room temperature was confirmed by x ray to be associated with a molecular dissociation. The molecular dissociation was first observed at 150 K at a higher pressure around 43 GPa . ...
The magnetization of Ce2Fe17 was precisely measured under high pressures up to 1.2GPa in magnetic fields up to 18T. The magnetic phase diagram in the B-T plane is determined at 0, 0.3, 0.4, 0.6, 0.9 and 1.2GPa. At 0GPa, five magnetic phases exist and the application of high ...
We performed high-pressure transport measurements on high-quality single crystals of KOs2O6 , a ? -pyrochlore superconductor. While the resistivity at high temperatures might approach saturation, there is no sign of saturation at low temperatures, down to the superconducting phase. The anomalous resistivity is accompanied by a ...
This experimental investigation of the migration of a gas solution through slightly permeable rocks at high pressures revealed that it is accompanied by a chromatographic separation of the components and fractionation of the carbon isotopes of hydrocarbons. Carbon isotope separation is characteristic of methane (up to 1%) and liquid ...
Flotation of early-formed plagioclase in the layered gabbroic Kalka Intrusion of central Australia was accompanied by gravitational ettling sof co-crystallizing pyroxenes. Remelting of the rising plagioclase upset the normal gravitational crystal-extractive processes which control classic basaltic fractionation trends. Together with high ...
The electron-correlation driven metal-insulator (Mott) transition in pyrocholore-type R2Mo2O7(R being rare-earth-metal ions) is accompanied by the change of the magnetic state from ferromagnetic to spin glass due to the competing double-exchange and superexchange interactions on the frustrated lattice. By application of high pressures ...
The techniques of backward stimulated Raman scattering (BSRS) and reflected broad-band coherent anti-Stokes Raman scattering (RBBCARS) have been used to measure vibrational frequency shifts in shock-compressed liquid benzene and mixtures of liquid benzene and liquid deuterated benzene. BSRS was used only for measurements in neat liquid benzene as it only allows observation of the highest gain ...
The phase diagrams of NaSO4 and Na2CrO4 were determined to 45 kbar. Two new high-pressure phases were found for Na2SO4. Eight different solid phases, one of which is metastable, are now known for this substance. Three new high-pressure phases were found f...
Raman spectroscopy and x-ray diffraction measurements have been performed for pure Cr2O3 to 61 GPa at ambient temperature with and without laser heating. Several changes were found at 15 30 GPa under cold compression: splittings of two Eg phonons, steep selective increase of some phonon intensities, softening of low-frequency phonon modes, selective broadening of some diffraction lines, systematic ...
Time-of-flight neutron powder diffraction offers unique capabilities for structural studies at high pressure. Scientific applications have included studies of compression mechanisms, new high-pressure structures, and phase transitions. 11 refs., 1 fig.
We extend our multicomponent fuel model to high pressures using a Peng-Robinson equation of state, and implement the model into KIVA-3V. Phase equilibrium is achieved by equating liquid and vapor fugacities. The latent heat of vaporization and fuel enthalpies are also corrected for at high ...
We performed the single-crystal X-ray diffraction study of a perovskite-type gold mixed-valence compound, Cs2AuIAuIIICl6, under high pressures up to 18 GPa by using a diamond-anvil-cell with helium gas as an ideal hydrostatic pressure-transmitting medium. The lattice parameters and the variable atomic positional parameters were obtained with reasonable ...
New phenomena the first order magnetic phase transitions were observed in nanoclusters and nanostructures. For isolated ferrihydrite nanoclusters (d � 1 2 nm) in porous materials, for ?-,?-Fe2O3 nanoclusters (d � 20 50 nm) and for composites of nanostructured metallic Eu with additives of ?-, ?-Fe2O3 nanoclusters and adamantane the critical temperatures (T C, T N) and ...
