Abstract:
Thin films of magnetic materials with bcc lattice structure are of the increasing technological interest. Nevertheless, understanding of surface features formation at bcc surfaces is still limited. In the first part of the seminar, we will present EU-NSF project MagDot, which aims to achieve multiscale description of epitaxial growth of magnetic nanostructures at surfaces. Our Prague's group investigate several subproblems: simulation of MBE growth of islands on bcc(110) surface, interplay between chemical ordering and strain relaxation, and kinetics of pulsed laser deposition method. These topic are studied in submonolayer growth regime by Monte Carlo simulations.

In the second part, we will provide some details of Monte Carlo (MC) modeling of epitaxial growth and afterwards we will present results of study of early stages of growth on bcc(110) surface. We start with the introduction of kinetic MC method, outline its difference from Metropolis MC and its preferences for simulation of MBE growth. Next we will briefly describe algorithm for simulation of MBE growth on bcc(110) surface. This algorithm then was used to investigate initial stages of island formation. We have studied dependence of island density and island average aspect ratio (a.a.r.) - parameter that describes island shape - depending on various physical parameters. We will present island configurations obtained by our model for different substrate temperatures and compare them with the experimental results. Besides island configurations, we will present dependency of a.a.r. on the temperature. Dependency of the island density on the temperature will be presented in the form of Arrhenius plot for different model parameters. To make our model relevant for the heteroepitaxial systems, e.g. Fe/Mo(110), we have introduced effect of strain caused by the lattice mismatch into our model. Influence of strain on island density and morphology will conclude our talk.