Ab initio molecular dynamics study of the local structures and migration behaviors of liquid Sb-based alloys

Abstract

High-purity Sb is widely applied in the semiconductor industry, infrared detection and non-volatile memory. An in-depth knowledge of the local structure and related properties in liquid Sb-based alloys proves to be highly advantageous in the purification of Sb. In this work, an ab initio molecular dynamics simulation was used to study the local structures, dynamical properties, electronic structures and migration behaviors of liquid X-containing (X = As, Bi, Cu, Fe) Sb-based alloys. Among these solute atoms, the distribution coefficient of As/Bi is much larger than that of Cu/Fe. The results showed that the local structures around As/Bi are looser than those around Cu/Fe. The local structure around As/Bi contains a higher fraction of low-index bond pairs than that around Cu/Fe, and its local topological order of triples is closer to pure Sb melt. The coordination polyhedrons using As/Bi as the centered atom have more relaxed short-range order clusters than those using Cu/Fe as the centered atom. Different local structures and chemical effects may lead to different migration behaviors of solute atoms in the Sb melt.