Mechanism of acoustically induced diffusional structuring of surface adatoms

摘要

Physical mechanisms of time-averaged structuring of adatoms induced by a standing surface acoustic wave (SAW) on a solid substrate are studied. Despite some similarity with conventional mechanisms based on averaging of fast oscillation-type motion or radiation-pressure effects, we demonstrate that, for diffusional (i.e., strongly damped) adatom motion, the origin of time-averaged structuring is essentially different. The proposed analytical model and kinetic Monte-Carlo (kMC) simulations reveal several distinct structuring regimes and directly relate them to the transient modification of diffusion barriers and adiabatic temperature variations induced by SAW strains.