Density functional theory study of influence of oxide thickness and surface alloying on Cl migration within α-Al2O3

Min Liu, Ying Jin, Bao Chen, Christofer Leygraf, Liping Wang, Jinshan Pan

Research output: Journal PublicationArticlepeer-review

10 Citations (Scopus)


Insertion and migration of chlorine atoms (Cl) in α-Al2O3 were studied by density functional theory calculations focusing on the influence of oxide thickness and doping by Mg, Cu and Si. Work function, electronic band gap, and insertion energy were calculated to explore thermodynamics of Cl migration. Partial density of state (PDOS) calculations revealed the role of dopants in the electronic character of metal–O and Al–Cl bonds. Work function data showed the effect of Cl insertion into the oxide film on the corrosion resistance. Cl can locate at an O vacancy (VO) with a large exothermic insertion energy, independent of oxide thickness, but can only locate at superficial Al vacancy (VAl) exothermically. The energy barrier for Cl migration via neighboring VO increases with oxide thickness, and is 2 ∼2.5 eV for thicker oxides. Cl insertion causes a work function reduction exceeding 2 eV, implying a decreased corrosion resistance. The inhibition of Cl migration by Si-doping can be explained by a more intense hybridization peak of Si–O over Al–O in the PDOS profile, while the reduction of energy barrier by Mg–/Cu-doping probably is due to the deviation of metal-s state from the Fermi energy, thus facilitating Cl movement within the oxide.

Original languageEnglish
Article number081508
JournalJournal of the Electrochemical Society
Issue number8
Publication statusPublished - Aug 2021
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films
  • Electrochemistry
  • Materials Chemistry


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