Spin anisotropy of ferromagnetic slabs and overlayers (invited)

Abstract

We calculate the spin anisotropy of ferromagnetic monolayers of Fe, Ni, V, and Co. We find the easy direction of magnetization is perpendicular to the plane of the monolayer for Fe and V, but in the plane for Ni and Co. The result for Fe explains why spin splitting but no spin polarization is observed in recent photoemission experiments on Fe monolayers. For thicker ferromagnetic slabs, the depolarization energy will quickly overwhelm the spin anisotropy and force the moment into the plane of the slab. This is illustrated by calculations for thicker slabs of Fe. Preliminary calculations of the anisotropy of a monolayer of Fe on Ag indicate that the Ag must be treated fully relativistically.