The ternary subsystem Sn-Sn4As3-SnTe

Abstract

Thermal analysis, metallographic, and X-ray procedures were used to investigate the Sn-Sn4As3-SnTe subsystem of the ternary system tin-arsenic-tellurium. The subsystem is of the simple eutectic type with no ternary compound formation. A binary eutectic valley runs across the diagram from the Sn4As3-SnTe binary eutectic at 576.5°C to a ternary eutectic which is indistinguishable from the Sn4As3-Sn binary eutectic at 231.3°C with 0.5 wt % Sn4As3 and 99.5% Sn. More than 90% of the compositional area is dominated by the primary freezing of an SnTe-rich phase, and an Sn4As3-rich phase is the first to crystallise from the melt over most of the remaining area. Terminal solid solutions are very restricted.