Origin of high piezoelectric activity in perovskite ferroelectric ceramics

Abstract

Dense (1-x)(Bi0.5Na0.5)TiO3-xBaTiO3 (BNT-BTx%, x = 3, 5, 6, and 7) ceramics exhibit large piezoelectricity for electrical poling below coercive fields. In particular, the piezoelectric activity and permittivity frequency dispersion have been found to be closely related. The significantly increased piezoelectric constant and sharply decreased permittivity frequency dispersion are observed to occur for poled ceramics under the critical poling electrical fields. These results suggest that the high piezoelectric response stems from poling electrical fields-induced-ordered nanodomains.

Unique high temperature polarization stability state in Bi0.5Na0.5TiO3-BaTiO3system at the morphotropic phase boundary

“…The composition dependence of domain morphology observed by TEM in BNT–BT ceramics was reported by Ma et al . The results illustrated that the nanodomains were common feather at MPB composition and microdomains were observed to occur far from MPB composition . In the recently reported phase transition for unpoled and poled BNT– x BT ceramics by electric‐field in situ TEM, a large poling electric field can force the nanodomains to merge into thin lamellar domain for x = 0.06 BNT– x BT ceramics .…”

Inverted electro-mechanical behaviour induced by the irreversible domain configuration transformation in (K,Na)NbO3-based ceramics

“…In many lead-free and lead-based piezoelectric ceramics, it is verified that regular ferroelectric domains correspond to minimum frequency dispersions in dielectric permittivity while nanodomains lead to strong frequency dispersions13373839. No significant frequency dispersion is found for x = 0.05 and x = 0.10 samples before and after poling process.…”

Electric-Field-Dependent Surface Potentials and Vibrational Energy-Harvesting Characteristics of Bi(Na0.5Ti0.5)O3-Based Pb-Free Piezoelectric Thin Films

“…Figure d shows the frequency dependence of the dielectric constant of the 0.94BNT–0.06BT thin films in the range of 10 2 –10 6 Hz after poling at a given electric field from 0 to 900 kV/cm. The dielectric constant of all of the samples decreased linearly with increasing frequency in the frequency range, which is typical in this film, as has been previously reported . It is postulated that the dipoles are more susceptible to electric displacement at lower frequencies.…”

“…The dielectric constant of all of the samples decreased linearly with increasing frequency in the frequency range, which is typical in this film, as has been previously reported. 33 It is postulated that the dipoles are more susceptible to electric displacement at lower frequencies. The decreasing tendency of the dielectric constant was reduced with an increasing applied field, as can be seen in the slope change with the electric field in the inset plot of Figure 2d.…”