Dielectric Relaxation and Internal Friction Related to the Mobility of Domain Wall in PZT Ferroelectrics

Abstract

The dielectric permittivity of Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) ceramics as a function of temperature was measured in the frequency range from 1 to 10 kHz. There exists a dielectric loss peak close to and below the Curie point, the height of which decreases as frequency increases. Although the peak moves towards higher temperatures with increasing frequency, the relaxation time disagrees with the Arrhenius description. In addition, the internal friction measurement at 1 Hz shows a mechanical loss peak that is of static hysteresis type. Therefore the viscous motion of domain walls in PZT is dominant in a certain frequency range of a few kHz. Dielectric loss as a function of temperature under frequencies from 1 to 10 kHz is modelled by using the dynamic equation for the viscous motion of domain walls. In the simulation, the dispersion of phase transition temperature inside the ceramics has been considered. The simulation results meet quite satisfactorily the experimental data. The two important parameters, viscous coefficient and pinning force constant, can be estimated.

Temperature dependence of the direct piezoelectric effect in relaxor-ferroelectric single crystals: Intrinsic and extrinsic contributions

“…9,22 Importantly, the peak in dielectric loss ͑tan ␦͒ and the minimum in mechanical quality factor Q that occurs just below the depoling temperature ͑or Curie temperature T C ͒ in ferroelectrics and ferroelastics are commonly attributed to domain wall motion. 29 Upon increasing temperature towards T C there is a decrease in order parameter, or polarization in the case of ferroelectrics. For tetragonal barium titanate and lead titanate, for example, this corresponds to a decrease in tetragonality.…”

“…30 Accordingly, the domain wall energy is reduced near T C , which leads to an increase in domain wall mobility. 29 This is manifest in a peak in loss tangent at the Curie temperature followed by a sharp decrease in the paraelectric phase; above T C , all extrinsic contributions from domain walls vanish as they do.…”

90° domain wall relaxation and frequency dependence of the coercive field in the ferroelectric switching process

“…20 Thus, when domains are moving a viscous force (F V ), which is assumed to be proportional to the domain speed, acts contrarily to the domain motion and must also be considered. The importance of the viscosity has been already considered theoretically and experimentally for explaining some polarization switching properties as switching time 5,52,53 and self-heating 20 as well as the dielectric properties 54 . By analogy with mechanical systems 55 figures 6 (a) and (b) show schematically, in a first approximation, the electrical (F E ), restoring (F R ) and viscous (F V ) forces acting on the domains during both the application and the removal of the electric field, respectively.…”

Dielectric loss study of oxygen vacancies and domain walls in Sr2Bi4−x/3Ti5−xVxO18 ceramics

“…The appearance of this peak can be explained as due to the viscous motion of domain walls, which is found in a lot of ferroelectric and ferroelastic materials. [12][13][14][15][16][17] The peak P 2 of SBTi around 230°C, which is frequency dependent, is considered related to the migration of oxygen vacancies, because the height of the peak decreases dramatically after annealing in the oxygen atmosphere. However, the activation energy, calculated from the slope of the logarithm of frequency versus reciprocal of temperature, is much larger than that of the point defects.…”