Structural and Magnetic Properties of Co-Cu Film Systems

Thin films of Co on Cu are studied with respect to structural and magnetic properties by means of STM, MOKE and spin sensitive electron capture from surfaces (ECS). Sub-monolayer coverages of Co have been deposited on vicinal Cu(lll) surfaces with steps oriented along (110). STM topographies revealed that on vicinal surfaces regular arrays of steps with {100} as well as with {111} minifacets can be prepared. As Co is deposited it aggregates on both types of surfaces at the steps. On the surfaces with the {100} facets the step array is rearranged into a configuration where double steps dominate. Along the {100} facets of the double steps the Co exists as one-dimensional structures. Magnetic properties, e.g. hysteresis loops, are measured for different Co thicknesses above one monolayer on low-indexed Cu(lll). The difference between the ECS and the MOKE hysteresis loops, respectively, afford insights into relations between bulk and surface magnetic properties.