First-principles simulation study on the effects of dopants on the cohesion of gold grain boundary

The effect of dopants on the cohesion of gold grain boundaries was investigated using the first-principles density functional theory of the thermodynamic model of Rice-Wang. Dopants that have a smaller diameter and lower electronegativity than gold are more beneficial on the cohesion of Au grain boundaries, which originate from both mechanical and electronic interaction, with the mechanical effect domineering. Dopants that bring up grain boundary cohesion should increase the ductility of Au wires. The method shows reasonable agreement with existing experimental data on calcium and berryllium-doped Au wires.