Regensburg 2022 – wissenschaftliches Programm
KFM 10.3: Topical Talk
Dienstag, 6. September 2022, 10:30–11:00, H5
Advanced Phase-field Simulation of Ferroelectrics and Antiferroelectrics — •Bai-Xiang Xu — Division Mechanics of Functional Materials, Institute of Materials Science, TU Darmstadt
Featured by high power density and high cyclic stability, ferroelectric (FE) and antiferroelectric (AFE) perovskites are distinct type of materials for energy storage and conversion particularly in pulse power equipment, miniaturized electronic devices and electronic control system in electric vehicles. The key issue is to increase the energy storage density, which is strongly related to ferroelectric domain structure in the materials and its interaction with defects.
In this talk I will present advanced phase-field simulations on the domain scale of such energy materials. In the first part, by combining phase-field simulations with dislocation mechanics and driving force theory (Zhou et al. IJSS 2021; Höfling et al. Science, 2021), I will show simulation results and mechanistic understanding on domain wall-dislocation interaction in mechanically hardened ferroelectrics and its impact on properties. In the second part, a high order gradient phase-field model for antiferroelectrics will be presented (Liu and Xu, Script Mat. 2020). It enables simulations of the newly observed incommensurate modulations of (anti-)ferroelectric polarization configuration, which goes beyond the capability of the established models like the Kittel sublattice model. Simulations on the domain structure, hysteresis, and temperature induced FE-AFE phase transition will be shown, along with the comparison to experimental results.