Regensburg 2007 – wissenschaftliches Programm

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DF: Fachverband Dielektrische Festkörper

DF 11: Poster Session

DF 11.5: Poster

Donnerstag, 29. März 2007, 14:30–18:00, Poster C

Electron Holography on Ferroelectric 180°-Domains coupled "head-to-head" — •Christopher Matzeck, Hannes Lichte, and Marianne Reibold — TU Dresden, Triebenberg-Labor

Ferroelectric polarization modulates both amplitude and phase of the electron wave in an electron microscope, which can be measured by electron holography. In [1] is described that the gradient, respective the increase of the phase of the modulated object wave, is proportional to the projected ferroelectric polarization. Hence, the analysis of the gradient of the phase gives information about the domain coupling.

Ferroelectric domains are assumed to be not capable of arranging a stable configuration in head-to-head or tail-to-tail coupling, because, in that case, a charge would be found within the domain wall. This is not possible in an energetically stable state. However, several reconstructed phase images show a-domains that seem to be coupled head-to-head.

But a closer look discovers several hints that there could be a c-domain in between the others. Comparisons with simulations of a possible configuration match very well to the experimental data.

References:

[1] H. Lichte, M. Reibold, K. Vogel, M. Lehmann, Ultramicroscopy 93 (2002) 1999

[2] The financial support from the Deutsche Forschungsgemeinschaft for the Research Group on Ferroic Functional Components FOR520 is gratefully acknowledged