Influence of deposition rate and time on nucleation of Er on a-C

Nucleation kinetics of UHV deposited erbium on amorphous carbon at room temperature and for atom arrival rates of - is studied. For all deposition rates, the density of nuclei increased with time to a saturation value and remained stationary. It was found that the nucleation rate is linearly dependent on the deposition rate, indicating that a single-adatom constitutes a stable nucleus. At lower deposition rates (up to ), the saturation density is constant and independent of R but at higher rates it increases with R according to the mathematical function . It is shown that the nucleation theory usually used to explain the experimental work needs some revision.