Enhanced electrical properties in Ce/Mo co-substituted CaBi2Nb2O9 high-temperature piezoelectric ceramic.

In this paper, the synergistic effects of Ce⁴⁺ ions incorporation into the (Bi₂O₂)²⁺ layer and Mo⁶⁺ ions at the Nb site on the electrical properties of CaBi_2−xCe_xNb_2−xMo_xO₉ high-temperature piezoelectric ceramics were studied. The appearance of pseudo-tetragonal phase owing to the introduction of Ce⁴⁺ ions is beneficial to the polarization switching, and thus, an enhanced piezoelectric response (d₃₃ = 19 pC/N) was obtained in the x = 0.03 sample. Both the ferroelectric and dielectric properties of the doped samples are enhanced. Moreover, the reduction of the oxygen vacancies of the samples resulting from Mo⁶⁺ cations could also facilitate the improvement of electrical properties. As a result, a high Curie temperature (T_C = 941 °C) and good electrical properties (P_r =14.3 µC/cm², ρ = 1.1 × 10⁵ Ω cm at 600 °C) were obtained in Ce/Mo-co-substituted CaBi₂Nb₂O₉ ceramics. The results are rather important to explore the piezoelectric ceramics used in high-temperature environment. [ABSTRACT FROM AUTHOR]