Evolution of the morphology of small Co clusters grown on Au(1 1 1)

Abstract

The evolution of the morphology of small clusters grown on a complex surface containing a regular network of defects is investigated in the case of Co on Au(111). On the basis of molecular dynamics calculations the existence of a critical size for the transition from mono- to bi-layer islands is inferred. Rather than strain effects, the final bilayer morphology of the deposit is conditionned by the demixtion tendency in the bulk (Co, Au) alloy, favoring Co–Co bonds against heteroatomic ones, and surface tension effects both going towards a prefered three-dimensional growth.