Magnetic anisotropy of ferromagnetic Fe and Co thin films (invited) (abstract)

The observation of transition metal (TM) magnetic moments in thin films aligned perpendicular to the surface has focused theoretical and experimental attention on the origin of magnetic anisotropy in these exciting low dimensional materials. In this paper we report on a study of the magnetic anisotropy of Fe and Co thin films originating from the spin orbit interaction term of the fully relativistic Dirac equation. We employ a total energy second variation FLAPW method in which: (i) the electronic charge density is determined with the semirelativistic (no spin orbit) FLAPW method; (ii) relativistic eigenvalues are calculated via a variational procedure using the semirelativistic wave functions as basis. The magnetic anisotropy energy of free standing Fe(001) and Co(001) monolayers yields in plane orientation of the spin moment. Semirelativistic calculations determined the magnetic moments of 1Fe/1Au, 1Fe/1Ag, or 1Fe/1Pd-all (001) slabs; the results agree well with those of monolayer Fe on thicker substrates. Magnetic anisotropy results¹ for Fe monolayers on Au, Ag, and Pd(001) substrates give perpendicular anisotropy for these films, in agreement with experiment. Magnetic anisotropy calculations of Co thin films on CuPd and (001) and (111) substrates will also be presented. The origin of the magnetic anisotropy is discussed from a detailed analysis of the electronic structure (electronic bands, Fermi surface). Comparisons are given to the work of Gay and Richter and Fritsche et al.