Direct evaluation of domain-wall and intrinsic contributions to the dielectric and piezoelectric response and their temperature dependence on lead zirconate-titanate ceramics

Abstract

By making use of the fact that domain-wall motions do not produce volumetric changes, an experimental method is introduced to directly and quantitatively determine the domain-wall and intrinsic contributions to the piezoelectric and dielectric responses of a ferroelectric material. Utilizing this method, the contributions from the domain walls and intrinsic part as well as their temperature dependence for lead zirconate-titanate (PZT) 52/48 and PZT-500 ceramics are evaluated. The data show that at temperatures below 300 K, the large change in the dielectric and piezoelectric constants with temperature is due to the change in the domain-wall activities in the materials. The results confirm that most of the dielectric and piezoelectric responses at room temperature for the materials studied is from the domain-wall contributions. The data also indicate that in PZT-500, both 180° wall and non-180° walls are possibly active under a weak external driving field.

Influence of extrinsic contribution on the macroscopic properties of hard and soft lead zirconate titanate ceramics

“…on the other hand, in PFZT an anomalous behavior is observed on ε´/ε 0 in the range between 200 K and room temperature such that the dielectric constant has a relative thermal stability around room temperature, and its dielectric constant value is significantly lower than PnZT at room temperature. note that both the behavior and the value of the dielectric constant are very similar, under 200 K, independently of the type of doping, as has already been observed by other authors [3]. by extrapolating the curves of ε´/ε 0 , the value of the intrinsic dielectric constant of PZT at rhombohedral phase is 210.…”

“…by extrapolating the curves of ε´/ε 0 , the value of the intrinsic dielectric constant of PZT at rhombohedral phase is 210. Values of 350 have been reported for PZT at the morphotropic phase boundary [3], [9].…”

“…Zhang et al have shown that the intrinsic contribution to the material response can be considered nearly constant with the temperature. moreover, these authors make it clear that the extrinsic effect depends strongly on temperature [3]. The extrinsic effect consists in the motion of some elements (i.e., the domain walls) whose mobility tends to be null at absolute temperature (T = 0 K).…”

“…The first, called the intrinsic effect, is related to the polarization of the elemental cell and would be the sole response if the material was in a single domain state. The second, known as the extrinsic effect, includes all the phenomena different from the intrinsic effect, although it is commonly accepted in the literature that the major contribution to the extrinsic effect comes from the motion of the domain walls and their interaction with the lattice defects [3]- [5]. Zhang et al have shown that the intrinsic contribution to the material response can be considered nearly constant with the temperature.…”

“…Therefore, at very low temperature the response of the material can be due exclusively to the intrinsic effect. nevertheless, the extrinsic effect provides a major contribution to dielectric and piezoelectric response at room temperature and is therefore responsible for the excellent properties of PZT [3].…”