Subsolidus phase relations of the SrO-MO2-CuO systems (M = Ti, Zr and Hf) at 900 °C in air

The subsolidus phase relations of the SrO-MO2-CuO (M = Ti, Zr and Hf) systems were investigated in air. The samples were equilibrated at 900 °C. The SrTi4Cu3O12 compound is the only ternary oxide phase stable under these conditions in the investigated systems. This phase is non-stoichiometric, its actual composition being Sr0.95Ti4.05Cu2.95Ox. The SrO-ZrO2-CuO and SrO-HfO2-CuO systems have a similar structure. No Zr or Hf equivalents of the SrTi4Cu3O12 phase were formed under the present conditions.