First-principles calculation of the effects of partial alloy disorder on the static and dynamic magnetic properties ofCo2MnSi

On the basis of fully relativistic Korringa-Kohn-Rostoker calculations and in conjunction with the coherent potential approximation and the linear response formalism, we present a complete ab initio study of the influence of alloy disorder on the static and dynamic (Gilbert damping) magnetic properties and on the electronic structure of the half-metallic full-Heusler alloy ${\mathrm{Co}}_{2}\mathrm{MnSi}$. We discuss in particular partial atomic disorders intermediate between the main crystal phases $\text{L}{2}_{1}$, B2, A2, and $\text{D}{0}_{3}$ of this alloy. We compare our results with homemade experiments and measurements from the literature, and conclude that the presence of a partial $\text{D}{0}_{3}$-like disorder could explain the relatively high value of the Gilbert damping parameter and the lack of half-metallicity measured in real samples, in which alloy disorder cannot be totally avoided.