Strain Evolution of Highly Asymmetric Polycrystalline Ferroelectric Ceramics via a Self‐Consistent Model and In Situ X‐Ray Diffraction

Abstract

Strain and texture evolution (domain switching) of polycrystalline, ferroelectric BaTiO 3 was investigated in four-point bending geometry. Lattice strains were measured by in situ synchrotron X-ray diffraction to address problems related to modeling the constitutive behavior of highly asymmetric ferroelectrics. The hkl-dependent strain measured by X-ray diffraction was found to be smaller relative to both bulk strain measured by conventional, contact-based techniques and elastically computed strain, and reasons for this inconsistency are discussed. A self-consistent model with capabilities of quantifying domain switching and estimating hkl-dependent strain is applied to allow a direct comparison with diffraction data.

In situ characterization of polycrystalline ferroelectrics using x-ray and neutron diffraction

“…Three examples of stress-induced structural changes include phase transitions, domain wall motion (through the ferroelastic effect, predominantly during application of high stresses), and charge displacement (through the piezoelectric effect, during application of weak stresses). Some conditions under which such experiments can be conducted include the application of uniaxial or biaxial compression, [85][86][87][88] bending, 87 stresses near crack tips, 89 and conditions that induce domain wall creep. 90 In the case of applied stress, the analysis of diffraction data proceeds along similar lines to that undertaken for the in situ electric field experiments and the values calculated can include f 002 and volume of domains switched (g), lattice strains, and intensity ratios of specific peaks.…”

Quantitative analysis of domain textures in ferroelectric ceramics from single high-energy synchrotron X-ray diffraction images

“…In contrast, no 111 T domain texture is observed, as indicated by the almost invariant pole densities of $1 MRD, which is consistent with the fact that the 111 T lattice planes are not affected by domain switching in tetragonal ferroelectrics. 26 Furthermore, Figure 2(c) shows the 002 T , 200 T , and 111 T pole density distributions as a function of the angle a with respect to the poling axis. Some quantitative details of the texture including the pole figure maximum, ODF maximum and texture index are also summarized in Table II.…”