Stabilization of η-Cu₆Sn₅ Intermetallic Compound by Zn Addition: First-Principles Investigation

The structural phase transformation and electronic properties of Cu₆Sn₅ with and without Zn addition are analyzed based on the first principles calculations. The results indicate that the energy difference between the η phase and the η' phase decreases significantly after Zn addition at finite temperature. This implies that the high temperature η-phase Cu₆(Sn,Zn)₅ will be stabilized. Moreover, the bulk modulus is also improved after Zn addition. We attribute the corresponding structural stabilization to the relatively strong Zn–Cu and Zn–Sn bonding in the η-Cu₆(Sn,Zn)₅.