Journal of the American Ceramic Society, Vol.103, No.1, 266-278, 2020
The structure and electrical properties of Ca-0.6(Li0.5Bi0.5-xPrx)(0.4)Bi2Nb2O9 high-temperature piezoelectric ceramics
Ca-0.6(Li0.5Bi0.5-xPrx)(0.4)Bi2Nb2O9 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 (rho similar to 10(6) omega cm at 600 degrees C). The replacement of Pr3+ for A-site Bi3+ enhanced the piezoelectric property, and the piezoelectric constant d(33) increased from 13.8 pC/N to 16.3 pC/N. The high depolarization temperature (up to 900 degrees C) implied that CBN-LBP100x ceramics are promising candidates for ultrahigh-temperature application.