Thermal stabilities and properties of equilibrium phases in the Pt-Te-O system

The intermetallic phase PtTe was synthesized, and thermally analysed by the differential scanning calorimetry and thermogravimetry techniques, under both inert and oxidizing conditions. Based on the calorimetric measurements, the solidus and liquidus temperatures, and enthalpy of melting of PtTe in the phase region PtTe-Pt have been determined. For the first time, the maximum thermal stability of PtTe in an oxidizing atmosphere, close to the partial pressure of oxygen in air, is experimentally determined to be T = (603 ± 1) K, above which it oxidizes to form TeO2 and Pt. Based on experimental observations in this work combined with the literature review, isothermal ternary phase diagram of the Pt-Te-O system is proposed.