Surface diffusion measured by laser-induced desorption: Monte Carlo simulation of effects of surface defects on diffusion

Abstract

Recently, pulsed laser‐induced desorption (LID) has been used to measure surface diffusion of adsorbed species. Often, however, pulsed‐laser excitation leads to stress‐induced deformations of the surface. We have found, in the case of a Ni(100) surface, that laser excitation causes a change in the surface morphology that results in an increase in the dissociative sticking coefficient of hydrogen by a factor of more than 3. At the same time, adsorption of other species is not appreciably affected. Based on low‐energy electron diffraction (LEED) spot profile analysis, the laser‐irradiated surface has surface defects have on the measurement of diffusion by means of a Monte Carlo simulation. Surface defects are introduced into the simulation as trap sites because such defects would have the most pronounced effect on <named-content xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oasis="http://www.niso.org/standards/z39-96/ns/oasis-exchange/table" content-type="sem:AIPTh1.2" rid="kwd1.1...