Title

Self-diffusion of small Ni clusters on the Ni(111) surface: A self-learning kinetic Monte Carlo study

Authors

Authors

S. I. Shah; G. Nandipati; A. Kara;T. S. Rahman

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

Phys. Rev. B

Keywords

HOMOEPITAXIAL GROWTH; IR-X; MIGRATION; BEHAVIOR; CU(111); IR(111); AG; REPTATION; ADATOMS; MOTION; Physics, Condensed Matter

Abstract

We have examined the self-diffusion of small 2D Ni islands (consisting of up to 10 atoms) on the Ni(111) surface using a self-learning kinetic Monte Carlo (SLKMC-II) method with an improved pattern-recognition scheme that allows inclusion of both fcc and hcp sites in the simulations. Activation energy barriers for the identified diffusion processes were calculated on the fly using a semiempirical interaction potential based on the embedded-atom method. Although a variety of concerted, multiatom, and single-atom processes were automatically revealed in our simulations, we found that, in the temperature range of 300 K-700 K, these small islands diffuse primarily via concerted motion. Single-atom processes play an important role in ensuring that diffusion is random for islands containing 5 or more atoms, while multiatom processes (shearing and reptation) come into play for noncompact islands. The effective activation energy barriers obtained from the Arrhenius plot of the diffusion coefficients showed an increase with the size of the island, although there were interesting deviations from linear dependence. Several other processes also contributing to diffusion of islands were identified.

Journal Title

Physical Review B

Volume

88

Issue/Number

3

Publication Date

1-1-2013

Document Type

Article

Language

English

First Page

14

WOS Identifier

WOS:000321669800011

ISSN

1098-0121

Share

COinS