Mass Density of Liquid Selenium-Tellurium Mixtures at High Temperatures and Pressures

Abstract

The mass density of liquid Se–Te mixtures up to 20 at.% Te was measured by the Archimedean method in the temperature and pressure ranges up to 1350°C and 1200 bar. It was observed that at 20 at.% Te the isochore curves show maxima on the P-T plane. The thermal expansion coefficient α_P derived from the isochore curve data changes sign from positive to negative around 19 at.% Te at 1000°C and 100 bar. The concentration where α_P changes sign moves to Se-rich side by application of pressure. The anomalous behaviour in the isochore curve suggests the occurrence of the structural transition.