The structure and electrical properties of Ca0.6(Li0.5Bi0.5-xPrx)0.4Bi2Nb2O9 high-temperature piezoelectric ceramics

Abstract

Ca0.6(Li0.5Bi0.5-xPrx)0.4Bi2Nb2O9 ceramics were prepared via a solid-state reaction method. The effect of the Pr content on the structural and electrical properties was systematically investigated. X-ray diffraction (XRD) combined with Rietveld refinement and X-ray photoelectron spectroscopy (XPS) demonstrated that a moderate amount of Pr3+ can be incorporated into the NbO6 octahedra, while excess Pr3+ ions probably enter into the (Bi2O2)2+ layers, thus resulting in an increase in the tetragonality of the crystal structure. The introduction of Pr suppressed the generation of oxygen vacancies and improved the preferential grain growth along the c-axis, which might be responsible for enhancing the resistivity (ρ ~ 106 Ω cm at 600°C). The replacement of Pr3+ for A-site Bi3+ enhanced the piezoelectric property, and the piezoelectric constant d33 increased from 13.8 pC/N to 16.3 pC/N. The high depolarization temperature (up to 900°C) implied that CBN-LBP100x ceramics are promising candidates for ultrahigh-temperature application.