TWIN-FREE (CD, MN)TE SUBSTRATES

The complete pseudo-binary CdTe-MnTe phase diagram was drawn up by DTA. It shows a phase transition in the solid state from a high temperature phase, not unambiguously identified, to the low temperature ZB one. Bridgman grown (Cd, Mn)Te crystals present a high twinning density while those grown by THM, at a temperature lower than the phase transition one, were shown to be of twin free ZB structure, and highly purified beside the Bridgman ones. Microhardness measurements confirm that Mn destabilizes the Cd-Te bond. Twin-free (Cd Mn)Te crystals, with X-ray double crystal rocking curves of average FWHM {reversed tilde equals} 30 arc sec, appear nevertheless of reasonable substrate quality. © 1989.