Abstract: | In the SrS-Ga2S3 system, there exist two individual compounds: SrGa2S4 (a = 2.084 nm, b = 2.050 nm, c = 1.220 nm; congruent melting at 1530 K) and Sr2Ga2S5 (a = 1.253 nm, b = 1.203 nm, c = 1.117 nm; peritectic melting at 1330 K); both are orthorhombic. We discovered a compound of composition Sr4Ga2S7; this compound crystallizes in cubic system with the unit cell parameter a = 0.6008 nm, space group Pa3, and decomposes by a solid-phase reaction at 870 K. Eutectic compositions are 42 and 73 mol % Ga2S3; eutectic melting temperatures are 1210 and 1170 K, respectively. The SrS solubility in γ-Ga2S3 at 1070 K reaches 4 mol %. |