Selenium Solubility in Solid Zinc Selenide

摘要

Selenium solubility in solid s-ZnSe (F (4) over bar 3m) under mono- and divariant equilibrium conditions has been determined by a direct physicochemical method in the temperature range 850-1173 K. The maximum concentration of excess selenium is 3.76 x 10(-4) mol of excess Se per mole of ZnSe at 1173 K. The homogeneity range of the s-ZnSe phase has been shown to be characterized by retrograde solubility at its Se-rich phase boundary. A model has been proposed for defect formation in nonstoichiometric s-ZnSe at temperatures in the range 963-1173 K and p(Se) (2) pressures in the range 1.05 x 10(4) to 5.01 x 10(5) Pa according to which the dissolution of excess Se is accompanied by the formation of electrically neutral associated vacancy defects in the zinc sublattice.