Magnetic and structural properties of quaternary (Fe-Co-Ni)50Pt50 alloy thin films

The intrinsic perpendicular magnetic anisotropy constant K. for (Fe-Co-Ni)(50)Pt-50 quaternary alloy and (Fe-Cr)(50)Pt-50 alloy thin films is discussed as a function of structure and composition. Both M-s, and the estimated K-u values obtained by the extrapolation to order parameter S = I using the dependence of K-u on S become maximum at the valence electron number eta(elect) = 8, being independent of alloy system. The magnetic anisotropy is determined to the first approximation by the Fermi energy, which changes with the number of electrons, but not by the band structure itself.