Improved piezoelectric properties and thermal stability in ZnO-modified 0.39BiScO3-0.61PbTiO3 ceramics by structure regulation

Abstract

Listen

Translate article

In this work, ZnO was introduced into 0.39BiScO3-0.61PbTiO3 (xZn-BS-61PT), and the phase structure and local structure of ceramics were controlled by a combination of cation substitution and ceramic/semiconductor composite, so as to improve the piezoelectric properties and temperature stability of ceramics. Zn2+ substitute B-site Ti4+ of BS-61PT, resulting in a stable coexistence of rhombohedral (R)-tetragonal (T)-monoclinic (M) phases dominated by T phase. Excessive Zn ions displace the Sc ions, making Sc ions spontaneously crystallize at grain boundaries in the form of an oxide at x ≥ 0.015. The piezoelectric coefficient and Curie temperature (d33, Tc) are increased from (326 pC/N, 416 °C) for x = 0 to (431 pC/N, 433 °C) for x= 0.015. After annealing at 200 °C, the ZnO-modified samples still retrain high d33 value (d33 > 330 pC/N). For x=0.015 sample, after aged 12 months, the retrained d33 is 395 pC/N, only down 8%. The improved properties are attributed to the synergistic effects of phase structure, point defects and local electric fields. Our results provide a design strategy to simultaneously improve the piezoelectric properties and temperature stability. Meanwhile, it is beneficial to broaden the phase.boundary (MPB) composition range of BS-xPT ceramics, and reduce the dependence of performance on components.