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Showing 1 to 20 of 85 for “"lattice parameter"”.
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Lattice parameter and thermal expansion in solid methane
The lattice parameter of a methane CH4 single crystal with an oxygen impurity of 0.01% has been measured in the range 2.5 to 86.2 K with a precise, back-reflection x-ray camera. The lattice parameters differ significantly from previous imprecise values in the literature. A first-order transition …
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Influence of High Temperature Creep upon the Structure of ß-NiAl and ß-NiAl(Fe) Single Crystals
… the unit cell contents from the combined lattice parameter and mass density measurements, and refining the structure parameters according to the X-ray reflection intensity. Specifically, two special single crystal X-ray diffraction methods, namely the back reflection Kossel technique and …
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Thermal vacancies in hcp helium-4
… between 18.17 and 20.9 cm3/mole. Absolute lattice parameters at low temperatures were measured for many of these crystals. The temperature dependence of the relative lattice parameter was measured in selected crystals. This provided lower bounds on the vacancy activation energy. The …
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Thermal vacancies and phase separation in bcc mixtures of helium-3 and helium-4
… of the temperature dependence of the x-ray lattice parameter. A new x-ray diffractometer-position sensitive detector system is used to make measurements of the absolute lattice parameter of the helium crystals with an accuracy of 300 ppm, and measurements of changes in lattice parameter to …
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X-ray study of the stacking fault density near the hardness maximum of the Au-Ag-Pd system
… with the existing hardness map. In addition, lattice parameters, stacking fault densities, and spacing change fractions have been determined for those alloys. The lattice parameters were found to deviate negatively from Vegard's Law. For the alloys studied, the maximum deviation of 0.0091 A …
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Phase equilibria studies of Cr3O-type structures in the vanadium- rhodium-silicon and niobium-rhodium-silicon ternary systems
… in the V-Rh-Si system was also found. A minimum lattice parameter was found for samples closely approximating the stoichiometric Cr₃O composition in the V-Rh-si system. Either an increase or a decrease in vanadium composition from stoichiometry caused an increase in the lattice parameter of the …
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X -Ray and Pressure Measurements on Helium Solids
Lattice parameter data obtained from experiments at the National Synchrotron Light Source at the Brookhaven National Laboratory are also presented here. The vacancy formation energy of fcc 4He at 10.4 cm3 /mol was obtained by two different methods. In addition, c/a ratios were determined to be …
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Hydrogen in thin film niobium
… planes of the sapphire substrate. The concept of lattice roughness is introduced-this is the root mean square deviation in the out-of-plane direction, modulo the lattice parameter, of the atoms in each crystallographic plane. It is shown that lattice roughness leads to a Q dependent damping …
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Raman Scattering Studies of the Orbital, Magnetic, and Conducting Phases in Double Layer Ruthenates
Dilute La doping in Ca3Ru2O7 changes the lattice parameter along the c-axis and also adds an extra electron, providing bandwidth and band filling control, respectively. This addition of La also lowers the orbital ordering temperature to T ∼ 43 K, and provides a greater sensitivity of the …
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Thermal vacancies in HCP helium-4
… between 18.17 and 20.9 cm$\sp3$/mole. Absolute lattice parameters at low temperatures were measured for many of these crystals. The temperature dependence of the relative lattice parameter was measured in selected crystals. This provided lower bounds on the vacancy activation energy.
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Structural and Electromagnetic Study of Heavily Doped ZR-Added REBCO Coated Conductors Fabricated by Reel-To-Reel MOCVD
… chemical composition and the REBCO c-axis lattice parameter has been an important objective to create self-assembled growth of elongated perovskite oxide nanostructures at different Zr dopant levels. Maintaining an optimal texture of the epitaxial REBCO film amidst a high density of BMO …
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X-ray studies of gallium arsenide-silicon heterostructures
… potential. The large 4% mismatch in lattice parameter between the two semiconductors strongly affects disorder within the film and at the interface. We employ x-ray scattering to explore the structural properties of these layered materials grown by molecular beam epitaxy. The thermal …
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X-ray diffraction study of the high-density phases of solid 4He
… motions of the atoms about their mean lattice sites. While these distances can be as much as 25 % of the nearest-neighbor distance at the lowest densities, the atoms are significantly more confined ·as the density of the solid is increased. Since 4He is a highly compressible solid, it …
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Conformational studies of lithium phenyl stearate.
… diameter of between 33.9 to 36.8A. The hexagonal lattice parameter determined by X-ray diffraction has a value 35.9A. Also after the LiPS sample has gone through the phase transition beginning at >130°C, the hexagonal lattice parameter is 31.4A while the cylinder diameter lies between 30.2 and …
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Femtosecond pulsed laser deposition
… results will show the composition and lattice parameter of a film can be controlled by changing the relative laser fluences on the two targets. Films have been grown with enough extra Ga to compensate for the deficiency that commonly occurs when depositing from only one Nd:GGG target.
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Aluminum Beryllium Composites Produced by Rapid Solidification (Metastable Equilibrium, Modulus Hardening, Liquid Immiscibility)
… equilibrium cph and metastable bcc. A cubic lattice parameter of 0.25 (+OR-) 0.02 nm was experimentally determined by electron diffraction for the metastable bcc Be. A mechanism for the formation of the microstructure was described by a metastable phase diagram involving a liquid miscibility …
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On a Bimodal Distribution of Grain Size in Mechanically Alloyed Bulk Tungsten Heavy Alloys
… structure can accommodate. This is evinced in W lattice parameter values from the as-milled powders; while the lattice parameter drops considerable from 2 to 4 wt.% Ni, the difference between 4 and 6 wt.% Ni is much smaller and the Ni content limit surely falls between the two values. …
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Optical reflectance spectra of chromium (III) in MgO-ss
… ion, chromium, was investigated in a MgO host lattice. The chromium ion incorporated into poly-crystalline MgO by quenching from elevated temperatures allowed investigation of a single crystalline phase, MgO-solid solution (ss). The chromium ion was confirmed to occur in the trivalent state and …
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Oxygen Transport in Vapor-Deposited Tin-Doped Indium Oxide Films (Diffusion, Electrochemical)
… the films. Finally, thermogravimetric and x-ray lattice parameter measurements were made on Sn-doped In(,2)O(,3) powder to provide additional support for the defect model.
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DLC Thin Film Assisted ZnO Nanowires Growth
… were controllable by fine tuning the growth parameters and changing the DLC film deposition temperature. HRTEM examination confirms the NWs were single crystalline with c-axis preferred orientation (lattice parameter c = 0.519 nm). From our experiment results, a ZnO polycrystalline layer …
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