Effect of Au Doping on Elastic, Thermodynamic, and Electronic Properties of η-Cu6Sn5 Intermetallic.

The effects of substitution of Au for Cu on the elastic, thermodynamic, and electronic properties of hexagonal η-Cu₆Sn₅ intermetallic compound (IMC) are investigated by first-principles calculations. The results show that Au atoms preferentially occupy Cu4 or Cu3 site to form η-Cu₅Au₁Sn₅ or η-Cu₄Au₂Sn₅ IMC, respectively. Doping Au in η-Cu₆Sn₅ IMC forms a more stable thermodynamic structure than pure phase. The ductility of η-Cu₆Sn₅ IMC increases after substitution of Au for Cu. However, doping Au weakens the Young's modulus, shear modulus, hardness, and Debye temperature of η-Cu₆Sn₅ IMC. The results for the charge density difference, total density of states, and partial density of states show that doping Au atoms can stabilize the structure of η-Cu₆Sn₅ IMC. [ABSTRACT FROM AUTHOR]