A Metastable Intermediate Phase in the System Indium—Indium Antimony

Abstract

USING a technique for the ultra-fast quenching of thin metal foils from the melt by solid conduction (splat cooling)^1,2, we have recently shown³ that in many tin alloy systems a metastable phase of the ‘HgSn_6–10’ type⁴ (γ-phase, simple hexagonal, 1 atom/cell, a = 3.212 Å; c/a = 0.9312) can be obtained. This phase exists in equilibrium in the systems Sn-In, Sn-Cd and Sn-Hg, and could be retained in non-equilibrium at −190° C in the systems Sn + Pb, Ga, Zn, Cu, Ag, Au, Pd, Ca and Mg, at solute additions of 5–20 atom per cent, depending on the system. All these elements, in leading to the formation of γ, acted to reduce the valence electron concentration of tin to less than 4.0.