Adatom diffusion on vicinal surfaces with permeable steps

摘要

We study the behavior of single atoms on an infinite vicinal surface assumingcertain degree of step permeability. Assuming complete lack of re-evaporationan ruling out nucleation the atoms will inevitably join kink sites at the stepsbut can do many attempts before that. Increasing the probability of steppermeability or the kink spacing lead to increase of the number of stepscrossed before incorporation of the atoms into kink sites. The asymmetry of theattachment-detachment kinetics (Ehrlich-Schwoebel effect) suppresses the steppermeability and completely eliminates it in the extreme case of infiniteEhrlich-Schwoebel barrier. The average number of permeability events per atomscales with the average kink spacing. A negligibly small drift of the adatomsin a direction perpendicular to the steps leads to a significant asymmetry ofthe distribution of the permeability events the atoms thus visiting moredistant steps in the direction of the drift.