Wright-Patterson Air Force Base

About: Wright-Patterson Air Force Base is a other organization based out in Wright-Patterson AFB, Ohio, United States. It is known for research contribution in the topics: Laser & Microstructure. The organization has 5817 authors who have published 9157 publications receiving 292559 citations. The organization is also known as: Wright-Patterson AFB & FFO.

Processing high-temperature refractory-metal silicide in-situ composites

Abstract: High-temperature, refractory-metal, intermetallic, in-situ composites consist of high-strength, niobium-based silicides with a niobium-based metallic toughening phase. A variety of processing schemes have been used to generate these in-situ composites, including solidification and vapor phase processes. Secondary processing, such as forging and extrusion, has also been employed. These composites offer an excellent balance of high-and low-temperature mechanical properties with promising environmental resistance at temperatures above 1,100°C.

Infrared absorption of deep defects in molecular-beam-epitaxial GaAs layers grown at 200 °C: Observation of an EL 2-like defect

Abstract: Infrared optical absorption and Hall-effect techniques were employed to study deep defects in As-rich molecular-beam-epitaxial GaAs layers grown at very low temperature (200 \ifmmode^\circ\else\textdegree\fi{}C). A large ir absorption band was observed between 0.55 eV and the band edge. This band is composed of photoquenchable and photounquenchable components. Photoquenching, thermal recovery from the metastable state, and ir absorption properties of the quenchable defect, of estimated concentration of \ensuremath{\sim}3\ifmmode\times\else\texttimes\fi{}${10}^{18}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$, are identical to those of EL2. On the other hand, the unquenchable defect, of estimated concentration \ensuremath{\sim}3\ifmmode\times\else\texttimes\fi{}${10}^{19}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$, resembles the isolated ${\mathrm{As}}_{\mathrm{Ga}}$ antisite observed in neutron-irradiated GaAs. Both defects' concentrations, which show different isothermal annealing behavior are reduced by about an order of magnitude upon thermal annealing at 600 \ifmmode^\circ\else\textdegree\fi{}C for 10 min. This reduction is accompanied by an increase of sample resistivity by a few orders of magnitude.