Synergy of lead vacancies and morphotropic phase boundary to promote high piezoelectricity and temperature stability of PBZTN ceramics

Abstract

• A synergetic strategy including introducing lead vacancies by niobium doping and constructing an morphotropic phase boundary (MPB) was designed to improve the piezoelectricity and temperature stability. • Excellent piezoelectric properties ( d 33 =864 pC/N, k p =84%, T C =201 °C) and high temperature stability (less than 10% variations for electrical properties from 20 °C to 160 °C) are obtained simultaneously in PBZTN-0.540 ceramics. The flourishing development of emerging electromechanical applications has stimulated an urgent demand for ferroelectric ceramics with high piezoelectric properties and broad temperature usage range. However, it remains a challenge to simultaneously obtain good piezoelectricity and reliable temperature stability in lead zirconate titanate (PZT)-based piezoelectric ceramics. To solve this issue, a synergetic strategy was proposed to introduce lead vacancies through niobium doping and construct morphotropic phase boundary (MPB). In this work, Pb 0.905 Ba 0.085 (V Pb″ ) 0.01 [(Zr x Ti 1 -x ) 0.98 Nb 0.02 ]O 3 (PBZTN- x ) material system was designed. Good comprehensive properties ( d 33 = 864 pC/N, k p = 84%, T C = 201°C) and excellent temperature stability (less than 10% variation of electrical properties from 20°C to 160°C) were obtained in PBZTN-0.540 ceramics. Good piezoelectricity can be attributed to high extrinsic contribution (domain wall motion) induced by Pb 2+ vacancies and the existence of nano-domains emerged at MPB, while excellent temperature stability is mainly attributed to the minimized local stress in the lattice and the stable domain structure.