Domain wall formation in NixFe1-x.

In terms of a multiscale approach based on the Landau-Ginzburg expansion and on ab initio parameters evaluated by means of the fully relativistic screened Korringa-Kohn-Rostoker method, the width of domain walls is evaluated for the whole range of concentration in NixFe1-x. It is found that domain-wall formation occurs only for x<20% and x>55%; i.e., in the neighborhood of the structural phase transition from bcc to fcc, NixFe1-x first tends to form single domains before the actual range of concentrations of this phase transition is reached. The calculated domain-wall widths are found to be in reasonably good agreement with available experimental data.