High-pressure zinc oxysulphide phases in the ZnO–ZnS system

Abstract

Wurtzite–zincblende mixture, ZnO–ZnS (1:1 wt.%), was thermally treated at 5 GPa in order to explore a possible mutual solubility of the end members and formation of zinc oxysulphide phases under high pressure. The data on phase content, crystal structure, and microstructure from the X-ray diffraction and the scanning electron microscopy studies of the obtained compacts (ceramics) were compared and analyzed. It was found that as temperature is increased, the following processes occur in the ZnO–ZnS mixture under pressure: release of the mechanical stresses (between about 300 and 700 °C), recrystallization of the initial wurtzite and zincblende phases (700–900 °C), reaction between the end members (above ∼900 °C) that results in formation of mixed oxysulphides based on ZnO and ZnS, respectively, with the mutual solubility rate of about 8 mol.%.