Phase-Equilibrium Diagram in the Ternary System Y₂O₃-BaO-CuO

A phase-equilibrium diagram of the ternary system of Y 2 O 3 -BaO-CuO was investigated. The temperature vs concentration diagrams are given on four binary systems ranging from YBa 2 Cu 3 O 7- y to CuO, to BaCuO 2 ·3CuO, to 3BaCuO 2 ·4CuO and to 3BaCuO 2 ·2CuO mixtures. A liquidus line required for the preparation of YBa 2 Cu 3 O 7- y single crystal from solution was found to be extremely narrow in concentration range.