Nucleation, growth and morphology of Co thin films on Ag(110)

摘要

Scanning tunneling microscopy (STM) experiments reveal that Co growth on Ag(110), at coverages of Co < 1 ML and low substrate temperatures (～150 K), involves a concomitant insertion of Co into the top Ag layer and exchange of Ag out onto the surface. At 300 K, coverages of Co > 1 ML gives rise to a 3D nanocluster growth on the surface, with the clusters covered by Ag. Depending slightly on coverage, the clusters have a typical diameter of ～3 nm and a height of ～0.4 nm. Upon annealing to ～500 K, major changes are observed in the morphology of the surface. STM and AES show that there is a reduction of the number of Co islands on the surface, partly due to subsurface Co cluster migration and partly due to sintering into larger clusters.