Growth of the Pt/Cu Dendrites on Stepped Cu(111) Surface

The formation of Pt/Cu clusters on a stepped Cu(111) surface has been theoretically investigated using the self-learning kinetic Monte Carlo method. It has been shown that by varying Pt/Cu cluster growth conditions, one can prepare different nanostructures, such as spatially extended and branching dendrites and fingers of different geometry. It has been found that the shape of clusters depends mainly on three parameters: temperature, platinum relative concentration, and the type of step on which the cluster grows. Dendrites grow under the following conditions: the temperature in the system must be no higher than 200 K, and the system must contain platinum atoms. Depending on the type of step, either dendrites extended normally to the step or branching dendrites arise. At room temperature, fingers grow on steps, the length of fingers also being dependent on the type of step. Different shapes of clusters on different steps arise from the anisotropic diffusion of atoms near the corners of clusters, which can be explained by taking into account energy barriers for atom hops over the Cu(111) surface.