Employing density functional theory calculations we explore initial stage of
competitive alloying of co-deposited silver and indium atoms into a silicon
surface. Particularly, we identify respective adsorption positions and
activation barriers governing their diffusion on the dimer-reconstructed
silicon surface. Further, we develop a growth model that properly describes
diffusion mechanisms and silicon morphology with the account of silicon
dimerization and the presence of C-type defects. Based on the surface kinetic
Monte Carlo simulations we examine dynamics of bimetallic adsorption and
elaborate on the temperature effects on the submonolayer growth of Ag-In alloy.
A close inspection of adatom migration clearly indicates effective nucleation
of Ag and In atoms, followed by the formation of orthogonal atomic chains. We
show that the epitaxial bimetal growth might potentially lead to exotic
ordering of adatoms in the form of anisotropic two-dimensional lattices via
orthogonal oriented single-metal rows. We argue that this scenario becomes
favorable provided above room temperature, while our numerical results are
shown to be in agreement with experimental findings.Comment: 8 pages, 5 figure