SYMMETRY-INDUCED MAGNETIC-ANISOTROPY IN FE FILMS GROWN ON STEPPED AG(001)

Symmetry breaking at atomic steps of ultrathin Fe films grown on stepp ed Ag(001) substrates creates a uniaxial magnetic anisotropy with the easy axis parallel to the step edges. The relation between this induce d anisotropy and the step density is systematically investigated by ma gneto-optically scanning films grown on a curved substrate with a vici nal angle range between 0 degrees and 10 degrees. We find that (a) the uniaxial anisotropy depends quadratically on thr step density, and (b ) the spin-reorientation transition occurs at a larger thickness for t he stepped than for the hat film.