First-principles calculations of solute-vacancy interactions in aluminum

The interactions of solute atoms with vacancies play a key role in diffusion and precipitation of alloying elements, ultimately influencing the mechanical properties of aluminum alloys. In this study, first-principles calculations are systematically performed to quantify the solute-vacancy interactions for the 3d-4p series and the 4d-5p series. The solute-vacancy interaction gradually transforms from repulsion to attraction from left to right. The solute-vacancy binding energy is sensitive to the supercell size for elements at the beginning. These behaviors of the solute-vacancy binding energy can be understood in terms of the combination and competition between the elastic and electronic interactions. Overall, the electronic binding energy follows a similar trend to the total binding energy and plays a major role in the solute-vacancy interactions.