Curie Temperature Enhancement and Induced Pd Magnetic Moments for Ultrathin Fe Films Grown on Stepped Pd(001)

Abstract

Fe films grown in ultrahigh vacuum onto a curved Pd(001) substrate with a continuous gradient in atomic step density were studied in situ via the surface magneto-optic Kerr effect (SMOKE). The steps induce an in-plane, uniaxial magnetic anisotropy with the easy axis perpendicular to the step edges, and whose strength scales linearly with step density. The Curie temperature of 1--2 monolayers of Fe is enhanced by the steps relative to that on a flat substrate. The enhancement is attributed to a step-induced Pd moment at step edges, as inferred from the enhancement of the SMOKE signal with step density.