Phase Equilibria in the SrS—In2S3 System

Abstract

It was determined that the SrS—In₂S₃ system is of the eutectic type with the incongruently melting compound SrIn₂S₄ and limited regions of solid solutions based on polymorphic modifications of In₂S₃. The compound SrIn₂S₄ crystallizes in the orthorhombic system (space group Fddd) with the unit cell parameters a = 2.090 nm, b = 2.113 nm, and c = 1.302 nm. The incongruent melting point of SrIn₂S₄ is 1220 K, and its microhardness is H = 2650 MPa. The composition and melting point of the eutectic are 73 mol % In₂S₃ and 1170 K, respectively. The solubility of SrS in α-In₂S₃ at 1070 K reaches 6 mol % SrS.