ISOTHERMAL SECTIONS AND PRIMARY CRYSTALLIZATION IN THE QUASI-TERNARY YO1.5-BAO-CUOX SYSTEM AT P(O2) = 0.21 X 10(5) PA

The phase relations along the sections Y2BaCuO5-CuOx and YBa2Cu3O7-δ-CuOx at temperatures between 900 and 1100°C at 0.21 × 105 Pa O2 pressure have been investigated by DTA/TG and soaking experiments. Peritectic reaction temperatures have been observed to be 960°C and 940°C, respectively. The results have been combined with literature data to construct a consistent set of isothermal sections in the quasiternary YO1.5-BaO-CuOx system. A precondition of this consideration is the occurrence of only one type of melt which expands over wide ranges of the triangle as the temperature increases. The primary crystallization fields of solid phases have been derived. © 1993 Academic Press, Inc.