Impurity-induced island pinning during electromigration
Department of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), Universität Duisburg-Essen D-47057 Duisburg, Germany
Received: 11 February 2015
Accepted: 30 March 2015
We study the electromigration-induced drift of monolayer Ag islands on Ag(111) which contain one Cu atom. For this purpose a three-dimensional self-learning kinetic Monte Carlo model was extended, and a realistic many-body potential was used. The only free parameters of the model are the effective valences of the Ag and Cu atoms. Due to the impurity, the island drift is significantly reduced, especially for small islands. This is traced back to sequential pinning and depinning events, which are analyzed in detail. Surprisingly, this phenomenon is qualitatively independent of the impurity's effective valence, as long as the impurity does not detach from the island edge. How strongly the drift velocity is reduced depends on the effective valence.
PACS: 66.30.Qa – Electromigration / 05.10.Ln – Monte Carlo methods / 02.70.Uu – Applications of Monte Carlo methods
© EPLA, 2015