Large Piezoelectric Response and Polarization in Relaxor Ferroelectric PbTiO ₃ – Bi ( Ni _1/2 Zr _1/2 ) O ₃

Abstract

New binary system (1− x ) PbTiO 3 − x Bi ( Ni 1/2 Zr 1/2 ) O 3 ( PT –100 x BNZ ) with x ≤ 0.45 were synthesized via solid‐state reaction route. A morphotropic phase boundary ( MPB ) was identified around x = 0.40 by X‐ray diffraction ( XRD ) method. The ceramics with MPB composition exhibit enhanced ferroelectric properties. A large piezoelectric coefficient ( d 33 ) up to 400 pC/N was obtained for the PT –40 BNZ , which is comparable with the PbTiO 3 – BiScO 3 ( PT – BS , 450 pC/N).The frequency dependence of dielectric permittivity of PT –40 BNZ shows characteristic of a strong relaxor feature and a transition temperature around 290°C (1 MHz). Temperature effect on the unipolar strain was also investigated. The present system with high d 33 is a competitive piezoelectric material, as no expensive oxide is used here compared with the PT – BS .