High resolution electron microscopic investigations of dislocations in deformed GaAs single crystals doped with Te

The defect structure of GaAs single crystals doped with tellurium to about 1019 cm−3 and deformed at 500 °C is investigated in the high-resolution electron microscope using three-beam dark-field lattice images along 〈110〉. The images of precipitates at different stages of their formation as well as of dissociated 60° dislocations, dipoles, and stacking fault tetrahedra are taken and analyzed. The succession of the precipitation stages in the tellurium-bearing phase is analyzed, too. There are discrepancies between the periodicity on direct lattice images and the interplanar distances in highly deformed regions in the crystal.