Ab initio simulations and STM-images for Co/Pt(1 1 0) surfaces

We present results, obtained by first principles density functional calculations, simulating scanning tunneling microscopy (STM) images for 1.5 monolayer of Co deposited on a p(1×2) Pt(1 1 0) surface. Two different surface structures are investigated theoretically: a CoPt/Pt(1 1 0) film covered by a Co monolayer, and Co/Pt(1 1 0) covered by an ordered CoPt layer. The surface geometry has been fully relaxed minimizing forces on ions. Covering with a cobalt monolayer reveals a tendency to form double-rows, the CoPt covered film features surface rumpling. STM scans were simulated using perturbation theory, the influence of different tip compositions is analyzed. The results obtained are in reasonable agreement with experimental findings.