Eur. Phys. J. B 68, 479-485 (2009)
https://doi.org/10.1140/epjb/e2009-00100-1

Diffusion of tungsten clusters on tungsten (110) surface

¹ Department of Applied Physics, Hunan University, Changsha, 410082, P.R. China
² Department of Maths and Physics, Hunan Institute of Engineering, Xiangtan, 411104, P.R. China
³ Materials and Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China
⁴ Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99352, USA

Corresponding author: ^a wangyuhu2001cn@yahoo.com.cn

Received: 15 August 2008
Revised: 5 February 2009
Published online: 1 April 2009

Abstract

Using molecular dynamics simulation and modified analytic embedded-atom method, we have investigated the self-diffusion of clusters on a tungsten (110) surface. As compared to the linear-chain configuration, the close-packed islands for tungsten clusters containing more than nine adatoms have been predicted to be more stable with the relatively lower binding energies. The migration energies show an interesting and oscillating behavior with increasing cluster size. The tetramer, hexamer and octamer have obviously higher migration energies than the others. The different atomic configurations and diffusion mechanisms have been determined during the diffusion processes. It is clear that the dimer-shearing mechanism occurs inside the hexamer, while it occurs at the periphery of heptamer. The successive hopping mechanism of individual atom is of critical importance in the migration of the clusters containing five or fewer adatoms. In addition, the diffusion of a cluster with nine adatoms is achieved through the changes of the cluster shape.