Fundamental thermodynamic properties of the synthetic analog of the famatinite mineral - Cu3SbS4 were studied on the basis of electromotive force (EMF) measurements. The EMF of the concentration chains relative to the Cu electrode with a solid electrolyte was measured for the alloys from the Cu3SbS4 + Sb2S3 + S phase region at 300-380K temperature interval. Based on measurement data, the relative partial thermodynamic functions of copper in alloys, the standard thermodynamic functions of formation, as well as, the standard entropy of the Cu3SbS4 ternary compound were calculated for the first time.

Differential thermal analysis and powder X-ray diffraction methods were used for phase equilibria studying in the Cu3AsSe4-GeSe2 system. It was established that wide (up to 30 mol.%) solid solutions based on Cu3AsSe4 are formed. GeSe2-rich alloys consist of various heterogeneous mixtures, including phases outside the T–x plane of this section