Strain-gradient-induced electric polarization in lead zirconate titanate ceramics

Wenhui Ma, L. Eric Cross
2003 Applied Physics Letters  
Strain-gradient-induced polarization or flexoelectricity was investigated in unpoled soft lead zirconate titanate ͑PZT͒ ceramic where the texture symmetry ϱϱ m forbids macropiezoelectricity. Even under high strain gradient (1 m Ϫ1 ) the induced polarization is small (1.6 C/m 2 ) at 20°C. Higher strain gradients induce ferroelastic poling and an additional extrinsic contribution to the flexoelectric coefficient 12 raising the value from 0.5 to 2.0 C/m. Cooling through the Curie point (T C )
more » ... maximum stress ͑80 MPa͒ where the peak permittivity (ϳ20 000) could raise 12 to 20 C/m, the equivalent electric field is still only ϳ1 kV/m, inadequate to achieve significant ferroelectric poling. The situation may be different in thin PZT films where much larger strain gradients can occur.
doi:10.1063/1.1570517 fatcat:nynq6sxrwnew7os3nfwaoqwfse