Magnetic properties of ultrathin Fe films grown on stepped W(001) and Pd(001) substrates

In both Fe/W(001) and Fe/Pd(001) systems, the atomic steps induce an in-plane uniaxial magnetic anisotropy with the easy magnetization axis perpendicular to the step edges. The strength of the step-induced anisotropy was found to have a power law dependence on the step density: a quadratic dependence in the Fe/W system but a linear dependence in the Fe/Pd system. In addition, the Curie temperature is found to be higher on the stepped surface in the Fe/Pd system as compared to the flat surface. The enhancement of the Curie temperature is attributed to the step-induced Pd moments which is supported by the increased surface magneto-optic Kerr effect signal on the stepped surface. No such enhancement of either Curie temperature or magnetic moment was observed in the Fe/W system. (C) 1999 American Institute of Physics. [S0021-8979(99)27608-6].