Search

The homogeneity regions of zinc telluride ZnTe and cadmium telluride CdTe were studied by the "extraction" technique at 750-1365 K temperature range. It is shown that the homogeneity region of undoped ZnTe contains a stoichiometric composition. The existence of wurtzite-based ZnTe at high temperatures was proven and its lattice parameters were determined. A scheme of the 3C-2H polymorphous transition for ZnTe compounds is proposed in which the transition is followed by peritectic reactions at both the Te-rich and Zn-rich sides. In the case of CdTe, the solidus line near the melting point demonstrated an anomalous behavior, which could be explained in terms of the high-temperature polymorphous transition, but the polymorph was not fixed because of the low transition energy. The undoped ZnTe and CdTe single crystals were obtained by the Markov-Davydov vapor growth technique under pressures close to congruent sublimation conditions in the temperature range 1170-1320 K. The nonstoichiometry and impurity distribution in 60 mm diameter ZnTe and 100 mm diameter CdTe vapor grown crystals were examined. [ABSTRACT FROM AUTHOR]