Atomic scale investigations of the Co/Pt(111) interface structure and magnetic properties

Abstract

The interface structure of an ultrathin Co overlayer on a Pt(111) crystal was investigated with atomic-layer resolution medium-energy ion scattering spectroscopy and surface magneto-optical Kerr effect (SMOKE). For a 7 ML Co, interdiffusion begins at 673 K to form a heavily distorted Co-Pt surface alloy layer with little change in SMOKE intensity. However, annealing at 773 K formed a 30 atomic-layer-thick Co-Pt substitutional alloy with 3.7% maximum tensile strain, at which the SMOKE intensity increased more than 200%. The enhancement of the Kerr intensity is discussed with the interface alloy formation. (C) 2001 American Institute of Physics.