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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Quenching experiment for determination of effect of rhenium on vacancy clustering in molybdenum
Isothermal model parameters and activation energies for vacancy motion in defect annealing of antimony doped n-type germanium
Schroedinger equation in semiconductor with N atoms containing dislocation, vacancy or other defect, noting phase shift and local charge neutrality
Feasibility of using quenched-in defect technique to study effect of rhenium on vacancy clustering in Mo-35Re
Electron paramagnetic resonance of photosensitive donors in zinc oxide with oxygen vacancies
Recovery of deformed copper-palladium and gold- palladium alloys by isothermal and isochronal annealing, noting vacancy and interstitial migration
Etch-decoration technique of detecting vacancies in graphite has been used to determine the reaction rates of graphite with ozone in the directions parallel and perpendicular to the layer planes. It consists essentially of peeling single atom layers off graphite crystals without affecting the remainder of the crystal.
Association between vacancies and aluminum atoms in proton bombarded silicon with boron impurity
CdTe-HgTe heterostructures preparation with minimum energy gaps, showing photovoltaic effect caused by undesirable p-n junction due to Cd vacancy formation
Second harmonic phase matching temperature dependence of lithium niobate on melt composition, proposing mechanism involving lithium ion vacancies
Structure of ordered compound vanadium carbide, discussing carbon vacancy in hexagonal superlattice and domain structure
Intentional impurities effects on nitronium perchlorate thermal stability explained by change in cation and anion vacancies
Al/Zn/Mg alloys preprecipitation, discussing Guinier-Preston and critical zone sizes and reversible vacancy trap
Electron bombardment produced clustered displacements, paired vacancies and interstitial atoms in Si, discussing possible mechanism for developing defects
Calcium tungstate crystals, investigating electron paramagnetic resonance centers produced by neutrons and gamma rays to obtain information on lattice vacancies, defects, etc
Quenched and aged Pt, investigating secondary defects for vacancies clustering modes by transmission electron and field-ion microscopy
Measurement of the Hall coefficient as a function of temperature between 15 and 300 K allows the separate determination of donor and acceptor concentrations in silicon samples which were irradiated at 240 K by 1-MeV electrons and then thermally annealed at 300 K. In both lithium- and phosphorus-doped silicon irradiation increased the acceptor concentration and decreased the donor concentration due to the formation of vacancy donor pairs. Annealing did not change either concentration in phosphorus-doped silicon and caused both concentrations to decrease in silicon doped with moderate amounts of lithium. In addition to this, in both lithium- and phosphorus-doped silicon the concentration and energy level of the A center were measured at each point in the sample's history. This experiment was limited to float-zoned silicon doped with less than 6 x 10 to the 14th power donors per cu cm.
Electron microscopy has been used to observe the distribution and morphology of lattice defects introduced into lithium-doped silicon solar cells by neutron irradiation. Upon etching the surface of the solar cells after irradiation, crater-like defects are observed that are thought to be associated with the space charge region around vacancy clusters. Thermal annealing experiments showed that the crater defects were stable in the temperature range 300 to 1200 K in all of the lithium-doped samples. Some annealing of the crater defects was observed to occur in the undoped cells which were irradiated at the lowest doses.