First-principles calculations of Co7W6 doped with Re: Site occupancy and electronic properties

Using the first-principles calculations based on the density functional theory, we studied the site occupancy of Re in the Co7W6 μ phase and its effects on the electronic properties. The results of binding energy and defect formation energy show that the stability of the system was enhanced after Re doping, which indicates that Re is prone to the Co7W6 μ phase formation. The results of electronic properties calculations (the density of states and charge density difference) reveal that there exists a strong interaction between Re and its NN(nearest neighborhood) atoms, which was attributed to the d-d hybridization. Besides, the bonding strength becomes stronger as Re substituting the Co sites, which further elucidate that Re preferentially occupies the Co sites.