Transition from Mn4+ to Mn3+ induced by surface reconstruction at λ-MnO2(001)

Structural and electronic properties of the λ-MnO2(001) surface are investigated applying density functional theory approach. The calculations show that all Mn ions at unreconstructed smooth surface preserve the +4 oxidation state observed in the bulk. Upon the λ-MnO2(001) reconstruction, one fourth...

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Veröffentlicht in:The Journal of chemical physics 2010-11, Vol.133 (20)
Hauptverfasser: Ouyang, C. Y., Šljivančanin, Ž., Baldereschi, A.
Format: Artikel
Sprache:eng
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Zusammenfassung:Structural and electronic properties of the λ-MnO2(001) surface are investigated applying density functional theory approach. The calculations show that all Mn ions at unreconstructed smooth surface preserve the +4 oxidation state observed in the bulk. Upon the λ-MnO2(001) reconstruction, one fourth of Mn ions at the surface undergo a change of the oxidation state from +4 to +3, although the reconstruction does not change the Mn coordination number with oxygen. This is accompanied with the filling of initially empty 3\documentclass[12pt]{minimal}\begin{document}$d_{z^2}$\end{document}dz2 states localized on cations with one electron denoted by two neighboring O atoms. Although the reconstruction leads to an energy gain of 0.04 eV per surface unit cell, it is not a spontaneous process since it proceeds with an activation energy of 0.12 eV.
ISSN:0021-9606
1089-7690
DOI:10.1063/1.3509401