Low-temperature preparation and electrical properties of CaBi2Nb2O9 piezoelectric ceramic by addition of B2O3.

CaBi₂Nb₂O₉ ceramics were fabricated via the solid-state reaction method by the addition of B₂O₃ as a sintering aid at lower sintering temperatures than that prepared without B₂O₃. Ferroelectricity, piezoelectricity, and resistivity can be still greatly enhanced when the sintering temperature is decreased from 1075 °C for CaBi₂Nb₂O₉ to 975 °C for CaBi₂Nb₂O₉–0.25 wt. % B₂O₃. The high resistivity and weak c-axis texture ensure that the ceramics can be fully polarized in a high enough electric field. The increased spontaneous ferroelectric and remanent polarization result in a significant enhancement in the piezoelectric properties of CaBi₂Nb₂O₉–0.25 wt. % B₂O₃. The sample sintered at 975 °C possesses a high piezoelectric coefficient d₃₃ of ∼15.0 pC/N and resistivity of 1.4 × 10⁶ Ω cm (at 600 °C) along with a high ferroelectric Curie temperature T_C of ∼954 °C. This work is beneficial for the preparation of high-temperature piezoelectric ceramics with excellent electrical properties at a low sintering temperature. [ABSTRACT FROM AUTHOR]