First-principles investigation of the site preference and alloying effect of Mo, Ta and platinum group metals in γ′-Co3γ′-Co3(Al, W)

The alloying effect of Mo, Ta and platinum group metals on the properties of γ′-Co3γ′-Co3(Al, W) are studied using supercell models. It is demonstrated that Mo, Ta, Rh, Ir and Pt can stabilize the γ′γ′ phase, and three types of site preference are recognized. The binding energy and the lattice constant of the γ′γ′ phase is modified and the distinct alloying effect of those elements is further revealed by investigating the impurity-induced charge density and the partial density of states.