Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Many competing ceria (110) oxygen vacancy structures: From small to large supercells
KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
2012 (engelsk)Inngår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 137, nr 4, s. 044705-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

We present periodic "DFT+U" studies of single oxygen vacancies on the CeO2(110) surface using a number of different supercells, finding a range of different local minimum structures for the vacancy and its two accompanying Ce(III) ions. We find three different geometrical structures in combination with a variety of different Ce(III) localization patterns, several of which have not been studied before. The desired trapping of electrons was achieved in a two-stage optimization procedure. We find that the surface oxygen nearest to the vacancy either moves within the plane towards the vacancy, or rises out of the surface into either a symmetric or an unsymmetric bridge structure. Results are shown in seven slab geometry supercells, p(2 x 1), p(2 x 2), p(2 x 3), p(3 x 2), p(2 x 4), p(4 x 2), and p(3 x 3), and indicate that the choice of supercell can affect the results qualitatively and quantitatively. An unsymmetric bridge structure with one nearest and one next-nearest neighbour Ce(III) ion (a combination of localizations not previously found) is the ground state in all (but one) of the supercells studied here, and the relative stability of other structures depends strongly on supercell size. Within any one supercell the formation energies of the different vacancy structures differ by up to 0.5 eV, but the same structure can vary by up to similar to 1 eV between supercells. Furthermore, finite size scaling suggests that the remaining errors (compared to still larger supercells) can also be similar to 1 eV for some vacancy structures.

sted, utgiver, år, opplag, sider
2012. Vol. 137, nr 4, s. 044705-
Emneord [en]
Low-Index Surfaces, Electronic-Structure, Ceo2(111) Surfaces, Polaron Motion, Microscopic Observations, 1st Principles, Ceo2 Surfaces, Reduced Ceo2, Dynamics, Metal
HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-102633DOI: 10.1063/1.4723867ISI: 000307611500053Scopus ID: 2-s2.0-84961295303OAI: oai:DiVA.org:kth-102633DiVA, id: diva2:555834
Forskningsfinansiär
Swedish Research Council
Merknad

QC 20120921

Tilgjengelig fra: 2012-09-21 Laget: 2012-09-21 Sist oppdatert: 2020-03-10bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Andre lenker

Forlagets fulltekstScopus

Søk i DiVA

Av forfatter/redaktør
Hermansson, Kersti
Av organisasjonen
I samme tidsskrift
Journal of Chemical Physics

Søk utenfor DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric

doi
urn-nbn
Totalt: 51 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf