Effect of thermal cycling on the structure of low-temperature germanium telluride

Germanium telluride specimen with different deviations from the stoichiometry and subjected to different heat treatment cycles (hardening and high-rate heating cycles) have been X-rayed at room temperature and when heated to 450 deg C. It has been found that germanium-rich alloys exhibit phase composition stability under high-rate heating cycles over phase transition temperatures unlike tellurium-rich alloyes where the low-temperature modification structure is observed to be dependent on the thermal pretreatment conditions. It is hypothesized that the low-temperature γ-phase of germanium telluride is formed if preceded by the regular configuration of the nonstoichiometric defects in the α-phase. These defects begin to be regularized in the β-phase range