Meštrić, Hrvoje ; Eichel, Rüdiger-A. ; Koss, T. ; Dinse, Klaus-Peter ; Laubach, Sonja ; Laubach, Stefan ; Schmidt, Peter C. ; Schönau, Kristin A. ; Knapp, Michael ; Ehrenberg, Helmut (2005)
Iron-oxygen vacancy defect centers in PbTiO3 : Newman superposition model analysis and density functional calculations.
In: Physical Review B, 71 (13)
doi: 10.1103/PhysRevB.71.134109
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

The Fe3+ center in ferroelectric PbTiO3 together with an oxygen vacancy forms a charged defect associate, oriented along the crystallographic c axis. Its microscopic structure has been analyzed in detail comparing results from a semiempirical Newman superposition model analysis based on fine-structure data and from calculations using density functional theory. Both methods give evidence for a substitution of Fe3+ for Ti4+ as an acceptor center. The position of the iron ion in the ferroelectric phase is found to be similar to the B site in the paraelectric phase. Partial charge compensation is locally provided by a directly coordinated oxygen vacancy. Using high-resolution synchrotron powder diffraction, it was verified that lead titanate remains tetragonal down to 12 K, exhibiting a c∕a ratio of 1.0721.

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