Thermoanalytic investigations of the semiconductor TlSbSe 2

Abstract

Differential thermal analyses (DTA), dilatometric, and X-ray powder diffraction studies of the semiconductor TISbSe 2 show the existence of three phases. Between the high temperature (HT) phase with statistically distributed cations and the room temperature (RT) phase, an intermediate phase with partial cation order (PO phase) was found. The phase transition from HT to PO phase is of first order, where both displacement and atomic exchange processes occur. The phase transition from PO to RT is of higher order, accompanied by diffusion processes, which increase the order of the cations. The completely ordered RT phase can be obtained by long time annealing (e.g. four weeks at 350 °C). Another method to obtain the well ordered RT phase is to pass repeatedly the phase transitions without melting the material. The coefficients of thermal expansion have been measured for the temperature range from 25 to 300 °C.