STEP BARRIER FOR INTERLAYER-DIFFUSION IN FE FE(100) EPITAXIAL-GROWTH/

The interlayer diffusion barrier for Fe/Fe(100) deposition is estimate d by comparing the results of kinetic Monte Carlo simulations with exp erimental results in the first few monolayers of growth. We find that, in contrast to previous theoretical estimates for other systems, the step barrier for Fe/Fe(100) is small in comparison with the activation energy for diffusion on a hat terrace (0.454 eV). Our results resolve a long-standing controversy and provide quantitative support for the conjecture that the existence of mounds in this system is due to a fin ite positive step barrier.