Abstract
Equilibrium phase relationships for the pseudo-ternary systems PbO-CaO-CuO, PbO-SrO-CuO and PbO-CuO-SrO have been studied mainly by the X-ray diffraction method. The equilibrium phase diagram of the PbO-CaO-CuO system was drawn up at 700°C, 800°C and 850°C in air. The equilibrium phase diagram of the PbO-SrO-CuO system was determined at 700°C and 800°C in air. A part of phase diagram of the PbO-CaO-SrO system was drawn up at 800°C in air. At 800°C and 850°C, the regions of liquid or liquid+solids were determined in each systems. In the PbO-SrO-CuO system we found a new ternary solid solution. In the PbO-CaO-SrO system we found that (Ca1-xSrx2)2PbO4 was a solid solution of 0≤x≤1.0 at 800°C. The composition dependences of lattice parameters and decomposition point of a solid solution (CaxSr2)PbO4 were determined.