Plastic Deformation of CdTe Single Crystals. I. Microscopic Observations

Dislocation behaviour at room temperature in CdTe is studied in situ by both the transmission electron microscopy (TEM) and the scanning electron microscopy with the cathodoluminescence mode (SEM-CL). The etch-pitting method is also used. It is found by the TEM observation that dislocations cross-slip frequently,though they are often widely dissociated and glide in pairs. The motion of dislocations, including partials, is steady and continuous, indicating that the short range motion is controlled by the Peierls mechanism. Semi-microscopic observations by the SEM-CL and the etch-pitting method showed, however, that dislocations are apt to be immobilized and the deformation proceeds by multiplying new dislocations successively, suggesting that the macroscopic strain-rate is governed by the multiplication rate and the mean free path which is controlled possibly by jog formation by cross slips.