Statistical theory of hysteresis in ferroelectric materials

Abstract

A theory is developed based on the model of random interactions between a large number of lattice defects and domain walls in ferroelectric materials. The theory gives the characteristic parameters of the hysteresis loop such as initial dielectric constant εi, Rayleigh constant ν, and coercive field Ec in terms of the microstructure of the domain walls and the number and interaction strength of the lattice defects. Results from large amplitude measurements on BaTiO3 doped with Fe show that a linear relationship exists between the dielectric constant and the ac field as required by Rayleigh’s law. In addition, the Rayleigh constant itself is inversely proportional to the Fe concentration as predicted by the model. Therefore, it is concluded that Fe as a dopant in BaTiO3 can act as obstacles to domain wall motion and control the characteristics of the hysteresis loop.

Hardening-softening transition in Fe-doped Pb(Zr,Ti)O3 ceramics and evolution of the third harmonic of the polarization response

“…21,30,36,37 This law is valid for systems in which interfaces, such as domain walls, move in a spatially random energy landscape. Clearly, the Rayleigh law cannot be applied to well aged or poled hard materials were domain structure is configured by alignment (or ordering) of micro-or macro-dipoles with polarization within domains.…”

Improvement of ferroelectric fatigue endurance in multiferroic (Ba0.5Sr0.5)TiO3∕(Bi1.05La0.05)FeO3∕(Ba0.5Sr0.5)TiO3 sandwich structures

“…By fitting the experimental data, the values for init and ␣ of the BST/BLF/BST trilayer and of the BLF film are 177 and 165 cm/ kV, and 5.3 and 2.7 cm/ kV, respectively. According to Boser's discussion, 21 the value of 1 / ␣ is proportional to the concentration of defects that affect the motion of ferroelectric domain wall. Compared with the single BLF film, the Raleigh coefficient of BST/BLF/BST trilayer reflects the total contribution from BLF and BST layers.…”

Deaging and Asymmetric Energy Landscapes in Electrically Biased Ferroelectrics

“…The motion of a domain wall through the lattice can be described by a force profile which represents the distribution and strength of various pinning centers [6]. While the lattice itself contains periodic pinning centers (i.e., the Peierls potential [7][8][9][10]), most ferroelastic domain wall widths span several unit cells and these intrinsic effects are typically negligible [11].…”

“…For example, the field amplitude or frequency dependence of the electric-field-induced polarization [6,14] and strain [4] can be used to assess the total influence of all extrinsic (nonlattice) effects, including, e.g., domain wall and interphase boundary motion. This is done by determining the relative nonlinear contributions in a property coefficient that is intrinsically only weakly nonlinear within certain field (E) ranges.…”