Plastic deformation of GaAs single crystals as a function of electronic doping II: Low temperatures (20–300°C)

Abstract

Plastic deformation of GaAs single crystals has been studied in the temperature range 20-300°C as a function of electronic doping. Macroscopic plastic deformation was achieved by superimposing on the uniaxial stress a hydrostatic pressure. The effect of electronic doping has been found to be reversed compared to that found at medium temperatures. This effect is correlated to the occurrence of deformation mechanisms different from the medium temperature regime: screw dislocations were found to control the deformation (intrinsic and n-type) together with the glide of decorrelated partial dislocations (n, p, intrinsic). Cross-slip has been found to be activated at room temperature, the ability for cross-slip depending of the α or β nature of the leading partial on screw segments in n-type crystals. Additional experiments in which dislocations created at medium temperature are moved at room temperature under high stress confirm these results and the high mobility of the 90° α partial in n-type GaAs.