Dresden 2006 – wissenschaftliches Programm

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DF: Dielektrische Festkörper

DF 3: Poster Session

DF 3.3: Poster

Montag, 27. März 2006, 09:30–17:00, P1

Ferroelectric Polarization as the Gradient of Phase Shift in Electron Holography at Atomic Resolution — •Christopher Matzeck, Hannes Lichte, and Marianne Reibold — Dresden University, Inst. of Structure Physics, Zellescher Weg 16, 01069 Dresden, Germany

The transferred electron wave in Transmission Electron Microscopy is strongly influenced in phase by ferroelectric specimen. This gradient of the phase shift is directly proportional to the projected electric polarization within the sample [1]. Since Electron Holography allows measuring the phase modulation of an object wave, it is also capable of deducing the projected polarization in principle.Discovering ferroelectric dipoles in the phase images of Barium Titanate by means of Electron Holography [2] has opened quantitative characterization of single dipoles and nanodomains directly from phase images. The gradient can be determined numerically by the calculation of the differential quotient of the image data and displayed as a vector plot. This technique shows ferroelectric nanodomains in the range of only a few unit cells.

References:

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

[2] H. Lichte, M. Reibold, K. Vogel, M. Lehmann, D. Geiger, R. Goldberg, Proc. EMC 2004 (Vol. II), Antwerp, Belgium, 491-492

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