The structure of reconstructed chalcopyrite surfaces

Sascha Thinius, Mazharul M. Islam, Thomas Bredow

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Chalcopyrite (CuFeS2) surfaces are of major interest for copper exploitation in aqueous solution, called leaching. Since leaching is a surface process knowledge of the surface structure, bonding pattern and oxidation states is important for improving the efficiency. At present such information is not available from experimental studies. Therefore a detailed computational study of chalcopyrite surfaces is performed. The structures of low-index stoichiometric chalcopyrite surfaces {hkl} h, k, l ∈ {0, 1, 2} have been studied with density functional theory (DFT) and global optimization strategies. We have applied ab initio molecular dynamics (MD) in combination with simulated annealing (SA) in order to explore possible reconstructions via a minima hopping (MH) algorithm. In almost all cases reconstruction involving substantial rearrangement has occurred accompanied by reduction of the surface energy. The analysis of the change in the coordination sphere and migration during reconstruction reveals that S-S dimers are formed on the surface. Further it was observed that metal atoms near the surface move toward the bulk forming metal alloys passivated by sulfur. The obtained surface energies of reconstructed surfaces are in the range of 0.53–0.95 J/m2.

Original languageEnglish
Pages (from-to)1-9
Number of pages9
JournalSurface Science
Volume669
Early online date8 Nov 2017
DOIs
Publication statusPublished - 1 Mar 2018

Keywords

  • Chalcopyrite
  • Density functional theory
  • Global optimization
  • Minima hopping
  • Surface energy
  • Surface reconstruction

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

Cite this