X-ray diffraction study of the system Ga₂Se₃–In₂Te₃

A series of solid solutions in the system (Ga_xIn_1−x)₂(Se_xTe_1−x)₃, 1 ≥ x ≥ 0, were prepared by direct synthesis from α-Ga₂Se₃ and α-In₂Te₃. The samples (powders and single crystals) were examined at room temperature by X-ray diffraction. In the whole range of concentrations cubic phases of defect zinc-blende types (ZB) are present. The unit-cell parameter, a_ZB, continuously increases with the In₂Te₃ content, undergoing an abrupt change at x ≃0.5. In the Ga₂Se₃-rich region the diffraction lines show complex profiles, similar to the ones of α-Ga₂Se₃ and of (Ga_xIn_1−x)₂Se₃ in the Ga-rich region. In the In₂Te₃-rich region the diffraction pattern is similar to that of the disordered, β, phase of In₂Te₃. In a narrow range from x≃0.6 to x≃0.5 a two-phase region of these phases exists. For small values of x a superstructure appears, with the unit-cell parameter 3a_ZB, isostructural with the ordered, α, phase of In₂Te₃(F3m). The JCPDS Diffraction File No. for α-In₂Te₃ is 33-1488.