Effect of Ni doping on elastic properties, fracture toughness, electronic properties, and thermal conductivity of η'-Cu6Sn5 in Sn-Cu solder: A first-principles calculation

Abstract

The phase stability, elastic properties, fracture toughness, electronic structure and thermal conductivity of Ni-doped η'-Cu6Sn5 have been obtained using first-principles calculations. Four Cu and three Sn doped sites were taken into account on according to the crystal structure of η'-Cu6Sn5. The results showed that Ni-doped η'-Cu6Sn5 compounds are thermodynamically stable in the ground state. In addition, Ni also favors replacing the Sn sites. The doping of Ni atom increases elastic modulus and elastic anisotropy, and improves the plasticity of the alloy. In addition, the doping of Ni increases both the thermal conductivity and fracture toughness of η'-Cu6Sn5, while the doping of Ni atoms forms strong covalent bonds with neighboring Cu and Sn atoms, which enhances the chemical bond strength.