Pinning and depinning mechanism of defect dipoles in PMnN–PZT ceramics

Abstract

The frequency and temperature dependences of the hysteresis loops in Pb[(Zr 0.52 Ti 0.48 ) 0.95 (Mn 1/3 Nb 2/3 ) 0.05 ]O 3 ceramics have been investigated. The polarization-field hysteresis curves show 'pinched' shapes at room temperature and higher frequencies, whereas they display normal square-like loops at 200˚C and frequencies lower than 10 mHz. Critical ferroelectric features such as the coercive field, polarization and internal bias field show a strong frequency or temperature dependence. The close relations between the P -E loops and the applied frequency and temperature indicate that the defect dipolar moment may change its magnitude with variation of the frequency or temperature. Comparing with the intrinsic depinning procedure induced by the changes in the distribution of defect dipoles, we provide new evidence for an extrinsic depinning mechanism of the defect dipoles in the bulk ceramics.

Poling of hard ferroelectric PZT ceramics

“…1 Electrically, by repeated cycling (hundred or even thousands of times) of the hysteresis loop, the pinching will disappear and the internal bias will be reduced. 1,[20][21][22]32,34,35 This process is normally done above the Curie temperature 20,21 and is called hysteresis relaxation. 20,22 The relaxation of the internal bias E i obeys, according to Carl and Härdtl 22 :…”

Microstructural characteristics and electrical properties of xPb(Mg1/3Ta2/3)O3–(0.1−x)Pb(Mn1/3Sb2/3)O3–0.9Pb(Zr0.52Ti0.48)O3 high power piezoelectric ceramics

“…However, as discussed before the domain switching is pinned by defect dipoles due to the volume effect, which causes constricted loops even at a high field. It is presumed that a lower frequency than 1 Hz is helpful to observe more relaxed loops [19]. Here we compare only the results at 1 Hz and ∼45 kV/cm due to experimental limitations, and consider that the E c values measured under the same condition can reflect the intensity of internal defect diploes in the ceramics.…”

Processing and properties of ferroelectric relaxor lead scandium tantalate Pb(Sc1/2Ta1/2)O3 thin films

“…[12][13][14] Polycrystalline materials, such as those fabricated using a chemical solution deposition technique have large grain boundary areas that also serve to increase defect concentrations. It has been proposed that defects may impact polarization reversal and act as pinning centers, 15,16 and recently there has been direct observation of this phenomenon. 17 In addition, in chemical solution derived films, the pathway from an amorphous to a final crystalline state passes through an intermediate phase whose structure and stoichiometry is often different than the desired final phase.…”