Influence of crystallographic structure on polarization reversal in polycrystalline ferroelectric/ferroelastic materials

Abstract

Fabrication and simulation investigation of zigzag nanorod-structured graded-index antireflection coatings for LED applications

Multistep stochastic mechanism of polarization reversal in rhombohedral ferroelectrics

“…4(e,g,i)) followed by a slow saturation at long times. This feature is reminiscent of the switching behavior of PZT composition at the morphotropic phase boundary [32], which might occur due to the phase coexistence. The KNN material studied here is, however, a single-phase one as is evidenced by X-ray data analysis (Fig.…”

“…The KNN material studied here exhibits some dynamic polarization features different from tetragonal [8,34,[35][36][37]50,51] and rhombohedral [8,32,38] PZT compositions and a tetragonal Cu-stabilized 0.94Bi0.5Na0.5TiO3-0.06BaTiO3 (94BNT-6BT) material [36,61], which typically demonstrate a more or less smeared step-like behavior on the logarithmic time scale. Its behavior is also different from very dispersive response of (1-x)Ba(Zr0.2Ti0.8)O3-…”

“…A deeper insight into the complicated switching mechanisms in ferroelectrics/ferroelastics was gained by simultaneous measurements of the switched polarization and the macroscopic strain supported by in situ X-ray diffraction experiments performed on a polycrystalline ferroelectric lead zirconate titanate (PZT) of tetragonal symmetry [31]. Later the simultaneous polarization and the strain measurements were also performed on PZT ceramics of rhombohedral symmetry [32] and (K,Na)NbO3 (KNN)-based solid solutions [33]. An advanced quantitative analysis of the above-mentioned experimental data was performed by means of an original multistep stochastic mechanism (MSM) model developed first for the systems of tetragonal symmetry [34].…”

“…A combination of the MSM model with the inhomogeneous field mechanism (IFM) model [35,36], accounting for the distribution of the switching times due to the spatial distribution of the electric field, allowed the description of the simultaneous polarization and strain responses of tetragonal ferroelectric ceramics over a broad time range with high accuracy [37]. Further extension of the MSM model to ferroelectrics of rhombohedral crystallographic symmetry applied to the available experimental data [32] allowed extraction of fractions of 109°-, 71°-and 180°-switching events as well as their activation fields [38]. 4 No stochastic model is available yet for description of the time-dependent electromechanical response of orthorhombic ferroelectric/ferroelastic materials where possible 60°-, 90°-, 120°and 180°-switching events must be accounted for.…”

A phase-field model for ferroelectrics with general kinetics. Part I: Model formulation

“…By contrast, at higher rates bipolar curves show a strong rate dependence, a consequence of the finite kinetics of domain evolution (see, e.g., Wieder 1957;Chen et al 2011 andWieder 1957;Schmidt 1981;Yin and Cao 2002;Chen et al 2011;Kanann et al 2021 for rate-dependent hysteresis curves in single-and polycrystals, respectively). Another type of experiment, referred to as pulse experiment, determines the time evolution of the average polarization and strain in response to an applied pulse of the electric field (see, e.g., Merz 1954Merz , 1956Hubmann et al 2016for single-and Genenko et al 2012Schultheiß et al 2018Schultheiß et al , 2019. While no significant polarization reversal occurs during the short rise time of pulse loading (∼ 0.1 µs), polarization switching does occur during the subsequent constant applied electric field.…”