Dresden 2017 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 2: Various Topics I
DF 2.3: Vortrag
Montag, 20. März 2017, 10:10–10:30, GER 37
Flexoelectric Impact on the Formation of Domain Structures and the Polarization Switching in Thin Ferroelectric Films — •Ivan Vorotiahin1,2, Anna Morozovska2, Eugene Eliseev3, and Yuri Genenko1 — 1Institut für Materialwissenschaft, Technische Universität Darmstadt, Jovanka-Bontschits-Str. 2, 64287 Darmstadt, Deutschland — 2Institute of Physics, National Academy of Sciences of Ukraine, 46, pr. Nauky, 03028 Kyiv, Ukraine — 3Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, Krjijanovskogo 3, 03142 Kyiv, Ukraine
Flexoelectric effect (or flexocoupling) is one of the properties of solid state materials that couples the gradient of electric polarization with the gradient of mechanical strain. It exists virtually in all solids, but has so small magnitude that it cannot be effectively observed in most of them. However, with the reduction of dielectric film thickness, it might obtain a significant influence on the properties of dielectrics.
A process of 180∘ polarization switching and properties of domain structures in ferroelectric materials have been modelled,, using relations of Landau-Ginzburg mean-field theory. Static distributions of electric polarization and relevant quantities, including electric potential and mechanical stress, as well as dynamics of polarization switching are obtained and analysed. A role of the flexocoupling is estimated for both statics and dynamics. It appeared, that whilst having a small influence on the domain structure, flexocoupling can remarkably affect polarization switching times and the values of critical fields under which the switching occurs.