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DF: Fachverband Dielektrische Festkörper

DF 2: Nonlinear dielectrics, phase transitions, relaxors

DF 2.4: Talk

Monday, March 14, 2011, 12:00–12:20, KÖN Farb

(contribution withdrawn) Origin of polar nano regions (PNR) in relaxor ferroelectrics: nonlinearity, polaron formation and charge transfer — •Annette Bussmann-Holder — Max-Planck-Institut für Festkörperforschung, Heisenbersgtr. 1, D-70569 Stuttgart, Germany

A central issue in the physics of relaxor ferroelectrics is the origin of the formation of PNRs below some characteristic temperature scale. While it is often attributed to chemical disorder, random bond * random field appearance, local symmetry lowering, it is shown here that the huge intrinsic nonlinearity of ferroelectrics gives rise to spatially limited solutions of discrete breather type, which interact strongly with the remaining lattice. This scenario corresponds to a two-component approach to relaxor physics with decisive signatures in the dielectric spectra and strong charge transfer.