Regensburg 2019 – wissenschaftliches Programm
KFM 14.35: Poster
Mittwoch, 3. April 2019, 16:00–18:30, Poster C
Plastic deformation in polycrystalline BaTiO3 — •Marion Höfling1, Pengrong Ren2, Stefan Lauterbach1, Xijie Jiang1, Jurij Koruza1, Till Frömling1, and Jürgen Rödel1 — 1Department of Earth and Materials Science, Technische Universität Darmstadt, 64287 Darmstadt — 2School of Materials Science and Engineering, Xi’an University of Technology, Xi’an, P.R. China
Oxides can exhibit dislocations with charged cores and charge-compensating surrounding layers. These dislocations are in general considerably more temperature stable than point defects and have been described as one-dimensional dopants. Some recent publications have demonstrated that changing the dislocation density can be used to tune individual material’s properties, for example the ionic conductivity in TiO2 . In this study we investigated the plastic deformation of polycrystalline BaTiO3 as a possible means to introduce dislocations into ceramics. The creep mechanisms of BaTiO3 were determined at different temperatures and stresses based on the power law exponents obtained from high-temperature uniaxial compression experiments and a first approximation for a deformation mechanism map was created. Several samples were successfully plastically deformed on the border of the diffusion-dislocation creep regime and the resulting effects on the ferroelectric and dielectric properties were examined. Transmission electron microscopy (TEM) and piezo force microscopy (PFM) were carried out to identify the influence of the creep experiments on the microstructure and the domain evolution.
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