Influence of control and material parameters on island density in early stage of pulsed laser deposition

Abstract

We investigated how pulse frequency and pulse length influence the dependence of island densities on temperature in the early stage of pulsed laser deposition on bcc(110) surface. We compared two regimes of pulse frequency variation: one with constant average flux and the other with constant pulse intensity. We found that the effects on the values of island density and positions of plateaus corresponding to stable dimers and small island are opposite in the two regimes. In the former case, we found that the decreasing pulse frequency results in an enhancement of the island density without a shift of intervals of plateaus. In the latter case, we observed that a higher frequency leads to a higher island density, the levels of plateaus are conserved, but the corresponding temperature intervals are shifted towards a higher temperature. An increase in the pulse length for a given pulse frequency causes a decrease in the island density; the curve shift towards molecular beam epitaxy results for the pulse length comparable with the interval between pulses. The increase of the diffusion barrier for non-interacting monomers shifts the whole Arrhenius curve to higher temperatures and the increase of binding energy moves the position of plateaus to higher temperatures.