Point defect engineering of high temperature piezoelectric BiScO3-PbTiO3 for enhanced voltage response

BiScO3-PbTiO3 is the most promising system among high sensitivity piezoelectric BiScO3-PbTiO3 perovsldte solid solutions with high Curie temperature, which are under extensive investigation for expanding the operation temperature of state of the art Pb(Zr,Ti)O-3 (PZT) up to 400 degrees C. The viability of these alternative materials requires the development of specific point defect engineering that allow a range of piezoelectric ceramics comparable to commercial PZTs to be obtained, optimized for the different applications. A distinctive feature of BiScO3-PbTiO3 systems is the simultaneous presence of both Bi3+ and Pb2+ at the A-site of the perovskite. This enables the possibility of introducing charged point defects without incorporating new chemical species, just by defining an A site non stoichiometry. In this work, we present a comprehensive study of the effects of Bi substitution for Pb, along with the formulation of Pb vacancies for charge compensation. Results indicate an overall lattice stiffening that yields reduced polarizability and compliance, and dominates over a limited enhancement of the ferroelectric domain wall dynamics, so as a largely enhanced voltage response is obtained. Specifically, BiScO3-PbTiO3 with the A-site non-stoichiometry is shown to be very suitable as the, piezoelectric component of magnetoelectric composites for magnetic field sensing. (C) 2016 Elsevier Ltd. All rights reserved.