Magnetic properties of bulk NicFe1-c alloys, their free surfaces, and related spin-valve systems - art. no. 094417

Using the fully relativistic spin-polarized screened Korringa-Kohn-Rostoker method the magnetic properties of bulk NicFe1-c alloys, their free surface s, and (free surfaces) of related spin valves of the type NicFe1-c/Co4Cu5Co 4/NicFe1-c are calculated. It is found, that in the bulk systems the phase transition between fee and bce can be described very well in terms of spin and orbital magnetic moments, but also in terms of the magnetic anisotropy energy. The free surfaces and the spin-valve systems differ considerably fr om the corresponding bulk systems: free surfaces show a reorientation trans ition from a perpendicular orientation of the magnetization to in-plane at about 60% Ni, whereas the overall in-plane magnetization found in permalloy related spin valves can be mainly related to the contributions of the Co s labs to the band energy part of the magnetic anisotropy energy. In all case s investigated the (spin and orbital) magnetic moments for the free surface s are considerably enhanced at the surface with similar effects pertaining at the interfaces and the surface of the spin valves.