Large electric-field induced strain in BiFeO3 ceramics

TL;DR

This study demonstrates significant electric-field induced strain in BiFeO3 ceramics, comparable to lead-based materials, with strain influenced by frequency and defect dynamics, highlighting potential for actuator applications.

Contribution

It reports large bipolar strain in BiFeO3 ceramics at low frequency and high field, emphasizing domain switching and defect rearrangement as key mechanisms.

Findings

Strain up to 0.36% at 0.1 Hz and 140 kV/cm

Strain comparable to Pb-based perovskites

Domain switching and defect dynamics influence strain

Abstract

Large bipolar strain of up to 0.36% (peak-to-peak value) was measured in BiFeO3 ceramics at low frequency (0.1 Hz) and large amplitude (140 kV/cm) of the driving field. This strain is comparable to that achievable in highly efficient Pb-based perovskite ceramics, such as Pb(Zr,Ti)O3 and Pb(Mg,Nb)O3-PbTiO3. The strain showed a strong dependence on the field frequency and is likely largely associated with domain switching involving predominantly non-180{\deg} domain walls. In addition, rearrangement of charged defects by applying electric field of low frequency depins these domain walls, resulting in a more efficient switching and, consequently, an increased response.