Phase Equilibria in the Cu2Se-SnSe-CuSbSe2 System

Phase equilibria in the Cu2Se-SnSe-CuSbSe2 system were studied by differential thermal and X-ray powder diffraction analyses. Alloys were obtained by alloying of the preliminarily synthesized and identified initial compounds in a vacuum with subsequent annealing at 650 K for 500 h. Characteristic plots describing this system were constructed, namely, the polythermal sections SnSe-Cu3SbSe3, Cu2Se-[A], and CuSbSe2-[B], where [A] and [B] are the alloys of the compositions (SnSe)(0.5)(CuSbSe2)(0.5) and (Cu2Se)(0.5)(SnSe)(0.5), respectively; the isothermal section of the phase diagram at 300 K; and the projection of the liquidus surface. It was shown that this system is a quasi-ternary section of the quaternary system Cu-Sn-Sn-Se and is characterized by invariant equilibria: a transient one and a eutectic one. Fields of primary crystallization of phases and the types and coordinates of in- and monovariant equilibria were found. Wide regions of solid solutions based on SnSe and CuSbSe2 were revealed.