Regensburg 2013 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 1: Nano- and microstructured dielectrics

DF 1.2: Talk

Monday, March 11, 2013, 09:50–10:10, H11

Properties of ferroelectric domain boundaries investigated with scanning force microscopy — Jakob Frohnhaus, •Akos Hoffmann, and Elisabeth Soergel — Physikalisches Institut, Universität Bonn, Wegelerstrasse 8, 53115 Bonn

In lithium niobate (LiNbO₃), the ferroelectric polarization can only occur along the ± z direction resulting in the well-known 180^∘ domain boundaries (↓↑) which are generally used for applications such as periodically poled LiNbO₃ is used in nonlinear-optics. The two large faces of a z-cut crystal show the domain pattern as alternating +z, −z, +z, ... areas. Indeed, using a specific thermal treatment, also head-to-head domain boundaries (∑_↑^↓) can be generated. Obviously such a crystal exhibits only two domains, and consequently only one domain boundary, and the two large faces of a z-cut crystal are both −z-faces.

Scanning force microscopy (SFM) is known as a very versatile tool for highly resolved imaging not only of the surface itself but also of the materials’ properties. It is therefore possible to detect not only the topography but also the surface charge density, the piezoresponse, the conductivity, ... with high lateral resolution. We apply the varieties of SFM for the investigation and modification of these very different domain boundaries.