Phase diagram and commensurate-incommensurate transitions in the phase field crystal model with an external pinning potential

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • Western University
  • Oakland University
  • National Institute for Space Research
  • Brown University

Abstract

We study the phase diagram and the commensurate-incommensurate transitions in a phase field model of a two-dimensional crystal lattice in the presence of an external pinning potential. The model allows for both elastic and plastic deformations and provides a continuum description of lattice systems, such as for adsorbed atomic layers or two-dimensional vortex lattices. Analytically, a mode expansion analysis is used to determine the ground states and the commensurate-incommensurate transitions in the model as a function of the strength of the pinning potential and the lattice mismatch parameter. Numerical minimization of the corresponding free energy shows reasonable agreement with the analytical predictions and provides details on the topological defects in the transition region. We find that for small mismatch the transition is of first order, and it remains so for the largest values of mismatch studied here. Our results are consistent with results of simulations for atomistic models of adsorbed overlayers.

Details

Original languageEnglish
Article number021104
Pages (from-to)1-8
JournalPhysical Review E
Volume74
Issue number2
Publication statusPublished - 2006
MoE publication typeA1 Journal article-refereed

ID: 13369060