An X-ray diffraction study of the system Al₂Se₃In₂Se₃ in the In-rich region

A series of samples in the system Al₂Se₃–In₂Se₃ in the In-rich region have been synthesized and studied by X-ray diffraction. In the interval of the Al/In (molar) ratio r from r≳ 1/50 to r≲ 1/20 the system has a two-phase region, α + γ₁, where α is isostructural with the room-temperature modification of In₂Se₃, and γ₁ is isostructural with the second high-temperature modification, γ, of In₂Se₃. For r ≳ 1/20, ternary γ₁ alloys (Al_xIn_1−x)₂Se₃ are present alone and their unit-cell parameters decrease continuously as the Al content increases. These results are analogous with those obtained for the system Ga₂Se₃–In₂Se₃ in the In-rich region. The samples have also been studied by differential thermal analysis and electron-probe microanalysis.