SELF-ASSEMBLY OF FEW-ATOM CLUSTERS IN A MODEL OF A STRAINED SUBMONOLAYER

摘要

We consider an atomistic model of a coherent epitaxial sub-monolayer which is strained due to the lattice mismatch with the substrate. We argue that the same interactions which lead to the size calibration of two-dimensional islands according to the mechanism proposed by Priester and Lannoo may lead to a considerable slowing down of atomistic kinetics similar to that observed in glassy materials. To show this, we develop a formalism that is suitable for large-scale numerical simulations. Assuming pair-wise interatomic interactions and treating the lattice-mismatch-induced atomic displacements in the harmonic approximation, we map the system onto a lattice-gas model with multi-atom cluster interactions. In the simplest case, the cluster interactions reduce to a repulsion between linear atomic triplets. In the presence of competing attractive pair interactions of comparable magnitude this leads to frustration and kinetic glassy phenomena such as aging.