Structural transformations in Cu_2−x S and Cu_2−xIn_yS crystals

Abstract

Structural phase transitions in Cu_2-xS single crystals and the effect of partial replacement of copper by indium on the behaviour of these transformations have been studied by the X-ray diffraction. At room temperature, a metastable high-temperature FCC modification is shown to exist in Cu_2-xS with x = 0.25, 0.20 and 0.15 along with orthorhombic (anilite) and monoclinic (djurleite) phases. At room temperature, Cu_2-xIn_yS crystals, with x = 0.25, 0.20, 0.15 and y = 0.05 consist of orthorhombic (anilite), monoclinic (djurleite) phases and their metastable (FCC)₁ and (FCC)₂ modifications, which differ in the concentrations of metal atoms and unit cell parameters. At increased temperatures, after the orthorhombic and monoclinic phases transform to (FCC)₁ and (FCC)₂, each FCC phase retains its individual nature.