The effects of magnetic annealing of transition metal alloys deduced from ab initio electronic structure calculations

A theory is presented for describing the effects of annealing magnetic allo ys in magnetic fields. It has an ab initio spin-polarized relativistic Korr inga-Kohn-Rostoker coherent potential approximation (KKR-CPA) electronic st ructure basis and uses the framework of concentration waves. Alloys which w ould otherwise be soft magnets are found experimentally to develop directio nal chemical order and significant uniaxial anisotropy when annealed in mag netic fields. Our approach is able to provide a quantitative description of these effects together with the underlying electronic mechanisms. We descr ibe applications to the soft magnetic alloys permalloy and FeCo.