Effects of additive elements on structural and electronic properties of Sn-based intermetallics by first principles

Abstract

First-principles calculations are performed to study the structural and electronic properties of Sn-based intermetallic compounds (IMCs) with substitution elements. Cu atoms preferentially occupy the 2a sites in (Ni1 − x Cux)3Sn4 structures. With the increase of Cu content, the heats of formation (Hf) of (Ni1 − x Cux)3Sn4 structures become higher. For the Ni3Sn4-based ternary structures with different substitution elements, a simple rule for the Hf is obtained. Comparing with the substitution elements in group IB (Cu, Ag, Au), those from group VIIIB (Co, Ni, Pd, Pt) are more helpful for stabilizing the ternary structures. For substitution elements in the same group, the Hf of these ternary structures becomes lower with the increase of atomic number. This rule is verified by calculating the Hf of Cu6Sn5-based and AuSn4-based ternary structures.