Deaging and Asymmetric Energy Landscapes in Electrically Biased Ferroelectrics

Abstract

In ferroic materials, the dielectric, piezoelectric, magnetic, and elastic coefficients are significantly affected by the motion of domain walls. This motion can be described as the propagation of a wall across various types and strengths of pinning centers that collectively constitute a force profile or energetic landscape. Biased domain structures and asymmetric energy landscapes can be created through application of high fields (such as during electrical poling), and the material behavior in such states is often highly asymmetric. In some cases, this behavior can be considered as the electric analogue to the Bauschinger effect. The present Letter uses time-resolved, high-energy x-ray Bragg scattering to probe this asymmetry and the associated deaging effect in the ferroelectric morphotropic phase boundary composition 0:36BiScO 3 À 0:64PbTiO 3 .

Domain wall and interphase boundary motion in a two-phase morphotropic phase boundary ferroelectric: Frequency dispersion and contribution to piezoelectric and dielectric properties

“…Some of the field-amplitude-dependent results are reported in Ref. 43. Similar measurements in the present work are completed using field amplitudes less than half of the coercive field (< 0.5E c ).…”

Domain Wall Displacement is the Origin of Superior Permittivity and Piezoelectricity in BaTiO3 at Intermediate Grain Sizes

“…Additionally, for each grain size, the d 50 value during negative polarity is observed to be higher than that during positive polarity. The origin of this asymmetry is unknown, though asymmetries in strain behavior are often observed in ferroelectrics due to extrinsic effects [45]. Most importantly, Figure 6(d) indicates that change in d 50 due to the electric field application is maximum at the grain size of ~2 μm.…”

“…Such measurements provide a direct assessment of domain wall vibration (reversible) and small irreversible domain wall displacements at weak electric field strengths. Diffraction measurements at such weak fields can reveal the extrinsic contribution of domain wall motion to the property coefficients at conditions comparable to those used in the determination of macroscopic properties including relative permittivity and the piezoelectric coefficients [27,45,51,52]. Direct measurement of domain wall motion at weak field amplitudes can thereby provide further insight into the grain size dependence of 90 domain wall displacements and its relation to the relative permittivity and piezoelectric coefficient of BaTiO 3 .…”

“…Since the high-energy X-rays can penetrate a large volume of material, high-energy XRD effectively measures the collective effect of the microscopic displacements of domain walls. These measurements are therefore utilized to interpret the effect of domain wall motion on the macroscopic property coefficients [26,30,45].…”

“…While application of electric fields above E c results in large-scale domain wall motion (and, in certain grain sizes, a field-induced phase transition), small displacements of non-180 domain walls over local energy barriers at subcoercive field amplitudes (those below E c ) can be also measured using these X-ray approaches [30, 45,51,52]. Such measurements provide a direct assessment of domain wall vibration (reversible) and small irreversible domain wall displacements at weak electric field strengths.…”