Subsolidus phase relations of the SrO–RE 2O 3–CuO systems (RE = Tm, Lu and Sc)

Abstract

The subsolidus phase relations of the SrO–RE 2O 3–CuO (RE = Tm, Lu, Sc) systems were investigated in air. The samples were synthesised at 900 °C. The Sr 14− x RE x Cu 24O 41− δ solid solution was the only ternary phase formed for RE = Tm and Lu. The solubility limit of Sc in the Sr 14Cu 24O 41− δ phase is extremely low and substitution may take place on the Cu sites rather than on the Sr sites. The three systems comprise 6 three-phase regions and there are 2 two-phase regions in the systems including Tm and Lu. The structure of the SrO–Tm 2O 3–CuO and SrO–Lu 2O 3–CuO systems is similar to the one of the SrO–Yb 2O 3–CuO and SrO–Er 2O 3–CuO systems. There are however, significant differences in the SrO–Sc 2O 3–CuO system.