Phase Equilibria in the Cu2Se−SnSe−CuSbSe2 System

Resumo

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.