Phase diagram of the Bi2O3-SrO-CaO quasiternary system

Numerous reports have been published on the superconductivity, structure, and physical properties of the Bi-Sr-Ca-Cu-O system, including the ceramic superconductors of Bi[sub 2]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub y] and Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub y]. On the phase diagrams of the system, numbers of studies have so far been presented, but there exist several regions in the proposed phase diagram of the Bi[sub 2]O[sub 3]-SrO-CaO quasiternary system, which have been presented by several investigators, are different from each other because the ternary system includes a number of solid solution phases of which the phase equilibrium relations are complicated. In this study, isothermal sections of the phase diagram for the Bi[sub 2]O[sub 3]-SrO-CaO ternary system at 973 and 1,023 K have been investigated. Experiments were conducted in air, because this system does not include copper oxides and, therefore, it is considered that the oxygen contents in the interceramic compounds in this system are substantially not affected by the oxygen potential.