PHASE EQUILIBRIUMIN THE Cu2S – In2S3 – CuI QUASI-TERNARY SYSTEM

Abstract

The interaction between the components in the Cu2S – In2S3 – CuI system has been inverstigated by methods of X-ray analysis and differential-thermal analysis. An isothermal section of the quasi-ternary system at 770 K, two phase diagrams, three polythermal sections and the liquidus surface projection of the system were constructed. The isothermal section of the Cu2S – In2S3 – CuI quasi-ternary system at 770 K has been built based on the results of the X-ray analysis. The large regions of the solid solutions based on binary, ternary and quaternary compounds do not form at 770 К. The following one-phase regions were fixedat the temperature: κ-solid solutions based on Cu2S with cubic structure (S.G. Fm-3m), η-solid solutions based on CuI (S. G. F-43m), ε-solid solutions based on CuIn2S3I with a cubic structure (S. G. F-43m), δ′-solid solutions based on LTM-In2S3 (S.G. I-4/amd), μ-solid solutions based on CuIn5S8(S.G. Fd3m), γ-solid solutions based on LTM-CuInS2 (S.G. I-42d). These single-phase regions are separated by nine two-phase equilibria. The liquidus surface projection was built based on the two phase diagrams of In2S3 –CuI and CuInS2 – CuI systems and three polythermal sections CuIn5S8 –CuIn2S3I, CuInS2 –CuIn2S3I, CuInS2 – “Cu3SI”, which have been constracted in this work. In addition, literature data about the interaction in In2S3 – Cu2S and Cu2S – CuI systems have been used. The liquidus surface projection consists from the areas of primary crystallization of κ-solid solutions based on Cu2S, α-solid solutions based on HTM-CuInS2, β-solid solutions based on 2-HTM-CuInS2, γ-solid solutions based on LTM-CuInS2, μ-solid solutions based on CuIn5S8, δ-solid solutions based on HTM-In2S3, ε-solid solutions based on CuIn2S3I, η-solid solutions based on CuI. These areas are separated by 18 mono-variant curves and 17 non-variant points.

Keywords

• фазові рівноваги
• ізотермічний переріз
• проекція поверхні ліквідусу