Metastable Phases in the Pb–Sb and Pb–Bi Systems

Utilizing the splat cooling technique of rapid quenching from the melt, the Pb–Sb and Pb–Bi alloy systems were investigated at –190°C. In large parts of both systems, metastable single-phase alloys were obtained instead of equilibrium two-phase alloys. New phases found include a bcc (W-A2-type) Pb–Sb phase, a primitive cubic coordinated Pb–Sb phase (possibly of the NaCl–B1 type), and a complex Pb–Bi phase. The terminal solubilities, especially those of Pb in Sb and Bi, were strongly enhanced with an appreciable decrease of the rhombohedral angle α; atomic volumes are given.