Energy barriers for diffusion on heterogeneous stepped metal surfaces: Ag/Cu(110)
Abbreviated Journal Title
Thin Solid Films
Surface diffusion; Activation energy; Step edge; Molecular dynamics; simulation; Embedded atom method; Growth; Ehrlich-Schwoebel barrier; SELF-DIFFUSION; CU SURFACES; GROWTH; AG; HOMOEPITAXY; AG(001); AG(110); COPPER; ATOMS; Materials Science, Multidisciplinary; Materials Science, Coatings &; Films; Physics, Applied; Physics, Condensed Matter
In this paper we investigated the diffusion of Ag adatom by computing the energy barriers for many elementary diffusive processes which are likely to happen near to the step edge on Cu (110). The barriers are calculated by means of molecular dynamics simulation by using embedded atom potentials. The proximity to steps alters these barriers considerably, and very different results may be expected. In fact, our numerical calculations show that the diffusion via jump process along step edge is predominant for Ag/Cu(110) and the diffusion over the step occurs sometimes, but only via exchange mechanisms. The adatom diffusion across channels is difficult due to the high value of activation energy required (around 1 eV). Furthermore, we found the Ehrlich-Schwoebel barrier for diffusion around 120 meV in order to descend via exchange process and of the order of 170 meV via hopping mode. This aspect may have a strong influence on the growth character. In general our results suggest that, for our metal system, diffusion mechanism may be important for mass transport across the steps. Implications of these findings are discussed. (C) 2013 Elsevier B. V. All rights reserved.
Thin Solid Films
"Energy barriers for diffusion on heterogeneous stepped metal surfaces: Ag/Cu(110)" (2013). Faculty Bibliography 2010s. 4651.