Berlin 2018 – wissenschaftliches Programm

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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 11: Dielectric, Elastic and Electromechanical Properties

KFM 11.3: Vortrag

Dienstag, 13. März 2018, 10:40–11:00, EMH 025

Sequential polarization switching in ferroelectrics* — •Ruben Khachaturyan — Technische Universität Darmstadt, Darmstadt, Germany

The classical Kolmogorov-Avrami-Ishibashi (KAI) statistical theory of polarization reversal in a uniform ferroelectric medium proved to be a widely used tool in polarization kinetics description. However, based on independent nucleation mechanism the model is not able to describe subsequent events such as 90°-switchings which follow each other. Such 90°-switchings were established experimentally by in situ x-ray diffraction measurements and ultrasonic investigations.

In this work, we expand the KAI model to describe also sequential 90°-switchings. The model explains well recent experimental results of simultaneous time-resolved macroscopic measurements of polarization and strain, performed on a tetragonal Pb(Zr,Ti)O3 ceramic.

Results of simulation allow us to distinguish between 90°- and 180° switchings, estimate their shares as well as to determine characteristic switching times of these processes, and their activation fields.