HIGH-TEMPERATURE CREEP AND TRANSMISSION ELECTRON-MICROSCOPY OF GAAS

GaAs single crystals are compressed in the <111> direction in creep experiments. The dynamical recovery is investigated in the regime of steady state creep. It is controlled by cross-slip at higher temperatures (T > 820 K) and by climb at lower temperatures (T < 820 K). The corresponding activation energies are E(q)0 = 5.1 eV for cross slip and Q = 3.7 eV for self-diffusion (climb). The energy E(q)0 leads to a stacking fault energy gamma = 52 mJ m-2. The microstructure is investigated by transmission electron microscopy. A microscopic deformation model is proposed on the basis of the observed dislocation reactions in the analysed dislocation networks.