Switching Ti Valence in SrTiO3 by a dc Electric Field

Institut für Strukturphysik, Technische Universität Dresden, 01062 Dresden, Germany.
Physical Review Letters (Impact Factor: 7.73). 03/2009; 102(8):087601. DOI: 10.1103/PhysRevLett.102.087601
Source: PubMed

ABSTRACT A (001) SrTiO3 wafer has been investigated in situ at room temperature under application of a static electric field of varying polarity by fluorescence x-ray absorption near edge structure (XANES) analysis at the Sr-K and Ti-K absorption edges. The XANES spectra show a clear shift of the Ti-K absorption edge energy. The shift is attributed to a change of the Ti valence state in a volume invoked by diffusion of the oxygen ions and vacancies. No shift was observed for the Sr-K absorption edge energy. Theoretical calculations support these findings.

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