Subsolidus phase equilibrium in the Cu-Sb-O system

T6he study of the subsolidus phase equilibrium in Cu-Sb-O system was started using samples with compositions laying, at room temperature, in the CuO-Sb₂O₃ subsystem. Isothermal and non-isothermal experiments were performed to analyze the system in the 500–1000°C range. At high temperatures (over 500°C) the system transforms in a quaternary one: CuO-Cu₂O-Sb₂O₃-Sb₂O₅ as Sb₂O₃ undergoes oxidation to Sb₂O₄ and Sb₂O₅ and Cu₂O₃ reduces to Cu₂O. The formation of the CuSb₂O₆ and Cu₄SbO_4.5 binary compounds is reported. The calculations of mass variation and atomic composition modifications lead to a quaternary oxide representation of the subsolidus phase equilibrium.