ATOMIC VIEW OF SURFACTANT ACTION IN EPITAXIAL GROWTH: FROM STM TO COMPUTER SIMULATION

摘要

We have combined experiments and computer simulations to visualize the atomic mechanisms behind the surfactant role of Pb, Co, or Cu atoms deposited on Cu(111) covered with a Pb monolayer quickly getting buried beneath the latter. The presence of the surfactant induces a strong buckling in several substrate layers, which, in turn, modifies many of the system's properties. Atomic diffusion takes place below the surfactant by atomic exchange, while on the clean surface hopping dominates. The activation energy for surface diffusion or the adsorption energies are also significantly altered. These findings have important implications for the synthesis of novel heterostructures such as magnetic superlattices.