Partial Bi‐Sr‐Cu‐O Subsolidus Diagram at 800°C with and without Lithium Carbonate

Solid‐phase relationships have been determined for the Bi₂O₃–SrO–CuO system at 800°C in air with and without Li₂CO₃ mineralizer. Two ternary compounds were detected with Bi:Sr:Cu ratios of approximately 2:2:1 and a solid‐solution phase 11−;x:9+x:5 with 0x0.4. The solid‐solution phase is a 9 K super‐conductor at x=0.4. Two additional compounds with Bi:Sr:Cu ratios of approximately 4:9:1 and 2:7:2 are apparently stabilized by the presence of Li₂CO₃, but do not form without it. X‐ray crystallographic data are provided for each compound. Ramifications for quaternary Bi:Sr:Ca:Cu‐O superconductors are discussed.