The kinetics of spontaneous composition pattern formation in a quenched alloys under irradiation is numerically studied by means of phenomenological Enrique-Bellon equation for the local concentration field. In the present model the irradiation effect is modeled as a ballistic mixing with an average distance of atomic relocation R and its frequency Γ . Several two-dimensional computer simulations show that the competitive mechanism between phase separation and irradiation-induced mixing might provide a novel way to stabilize and tune the steadystate nanostructures of phase separating materials in some region on (R, Γ ) space.

No abstract

No abstract

No abstract

We present the kinetic equations that describe the coarsening of coherently strained two-dimensional circular islands on a substrate with a conserved small area fraction of islands. In this model, formulated in terms of a set of equations of motion for the island size and position, both Ostwald ripening mechanism and coherent misfit strain-induced elastic effects are taken into account. Large scale computer simulations demonstrate that the inter-island elastic interaction generates a repulsive force and results in the island migration, leading to a self-organized formation of a regular array of islands with both uniform size and spacing.1 Introduction Since the first achievement of self-organized growth of quantum dots (QDs) in the InGaAs/GaAs system [1], the investigation on strained two-and three-dimensional QDs has attracted a great deal of attention in semiconductor science and technology both from the viewpoint of basic physics and from the potentia applications. Thus, the QD formation is well established in various types of semiconductors, both by molecular beam epitaxy and by metal-organic chemical vapor deposition growth methods [2]. It is now widely recognized [3] that there exist two important factors regarding the mechanism of the QD formation in heteroexpitaxy growth, that is, the Ostwald ripening mechanism and the coherent misfit strain induced elastic effects. Although these two effects have been studied independently, much less is known about combined effects between them.In this work, to overcome their defects, we rigorously derive the kinetic equations of motion for the 2D island coarsening involving both Ostwald ripening mechanism and coherent strain induced elastic effects, and then carry out large scale computer simulations.