Phase relations in the Si–Sn–As system

The goal of this work was to study phase relations in the ternary Si–Sn–As system: to establish cross sections, to construct a scheme of phase equilibria, and to identify the temperature of non-variant transformations. Ternary alloys were obtained through direct synthesis from simple substances and subjected to long-term solid-phase annealing. Alloys of four polythermal sections of the Si–Sn–As system were examined using X-ray phase and differential thermal analysis. The results of X-ray powder diffraction allowed establishing that the phase subsolidus demarcations was performed by the SnAs–SiAs2, SnAs–SiAs, Sn4As3–SiAs, and Sn4As3–Si sections. As a result of the experiment, taking into account the theoretical analysis, we suggested a scheme of phase equilibria in the system that involved the implementation of eutectic and four peritectic invariant equilibria, and we used differential thermal analysis to determine the temperature of these four-phase transformations. It was found that extended solid solutions were not formed in the system, and only a substitutional solid solution at least 3 mol % wide was formed based along the SnAs–SiAs2 section based on tin monoarsenid