The structure and electrical properties of Ca _0.6 (Li _0.5 Bi _0.5‐ <i> _x </i> Pr <i> _x </i> ) _0.4 Bi ₂ Nb ₂ O ₉ high‐temperature piezoelectric ceramics

Abstract

Abstract Ca 0.6 (Li 0.5 Bi 0.5‐ x Pr x ) 0.4 Bi 2 Nb 2 O 9 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 Pr 3+ can be incorporated into the NbO 6 octahedra, while excess Pr 3+ ions probably enter into the (Bi 2 O 2 ) 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 ~ 10 6 Ω cm at 600°C). The replacement of Pr 3+ for A‐site Bi 3+ 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°C) implied that CBN‐LBP100 x ceramics are promising candidates for ultrahigh‐temperature application.