Composition and temperature dependences of site occupation for Al, Cr, W, and Nb in MoSi₂

The composition and temperature dependences of site occupation for Al, Cr, W, and Nb in MoSi₂ are investigated by using a thermodynamics model and first principles calculations. A simple parameter measuring the substitution energy difference between Si and Mo sites reflects the nature of site occupancy. At 0 K, these elements prefer Si sites in Mo-rich and Mo sites in Si-rich, and show no site preference in stoichiometric MoSi₂. At elevated temperature, the site occupation behaviors show strong dependence on both composition and temperature. Some calculated results have been certified in previous experiments.