Berlin 2005 – wissenschaftliches Programm

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DF: Dielektrische Festkörper

DF 5: Dielektrische und ferroelektrische dünne Schichten und Nanostrukturen I

DF 5.7: Vortrag

Montag, 7. März 2005, 12:20–12:40, TU TC6

Collecting the nanoscale optical hysteresis in ferroelectrics — •Tobias Otto, Frank Schlaphof, Hassan Chaib, Stefan Grafström, and Lukas Eng — Instititut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden

Ferroelectric switching is of clue interest for determining temporal and dynamic stability, but equally for the quantitative deduction of electronic and dielectric properties of ferroelectric domain structures. The methods reported so far, such as monitoring the switching current with macroscopic surface electrodes or collecting the nanoscale ferroelectric hysteresis by means of scanning probe techniques such as piezoresponse force microscopy (PFM), are all based on electrical or electro-mechanical effects.

In this paper we present for the first time nanoscale optical hysteresis measurements in barium titanate (BaTiO₃) single crystals using the electro-optical response [1] to monitor the polarization reversal. Nanoscale optical hysteresis loops obtained for several tip-sample separations are compared with nanoscale electrical switching recorded by PFM at the same surface spot. Finally, our experiments are discussed with respect to the effective electric field distribution under the probing tip as calculated by finite-element modelling [2].

[1] T. Otto et al., Appl. Phys. Lett. 84, 1168 (2004)

[2] T. Otto et al., Ferroelectrics 303, 149 (2004)