First-principles calculations of Zn substitutions in Cu6Sn5

First-principles calculations are performed to investigate the structural properties and phase stability of (Cu, Zn)6Sn5 and Cu6(Sn, Zn)5. Among these ternary intermetallic compounds (IMCs), Cu6ZnSn4 with Sn3 (4e) site substituted by Zn is the most stable. With the increase of Zn content, the heat of formation (Hf) of (Cu, Zn)6Sn5 structures becomes higher. This work further explores the effects of different substitutional elements (Co, Ni, Ag, Au and Zn) on the Hf of (Cu, M)6Sn5 (M is the alloying element) structures. The stability of these structures is closely relevant to the bonding energy of M–Sn and M–Cu bonds.