Commensurate-incommensurate transition and domain wall dynamics of adsorbed overlayers on a honeycomb substrate

¹ Department of Physics, Oakland University - Rochester, MI 48309-4487, USA
² Department of Applied Physics, Aalto University School of Science - P.O. Box 11000, FI-00076 Aalto, Espoo, Finland
³ Water Research Center for Agriculture and Mining (CRHIAM), University of Concepción - Concepción, Chile
⁴ Laboratório Associado de Sensores e Materiais, Instituto Nacional de Pesquisas Espaciais 12227-010 São José dos Campos, SP, Brazil
⁵ Department of Physics, Brown University - P.O. Box 1843, Providence, RI 02912-1843, USA

Received: 8 September 2016
Accepted: 22 December 2016

Abstract

We introduce an effective one-mode phase-field crystal model for studying the commensurate-incommensurate transition and domain wall dynamics of the phase found in systems such as Xe/Pt(111), or Xe and Kr on graphite. The model allows us to study large systems where the domain walls can be separated over large macroscopic distances and at the same time incorporate the microscopic details of the domain wall structures. The resulting phase diagram shows that an intermediate stripe incommensurate phase always separates the commensurate phase from the honeycomb incommensurate phases. The energy of the domain wall crossing is investigated. We also find that near a step edge, the domain walls tend to align perpendicularly to the step edge, in agreement with recent experimental observations.