Stable Piezoelectric Response Of 0-3 Type Cabi2nb2o9:Xwt%Bifeo3 Composites For High-Temperature Piezoelectric Applications

Depolarization in the ceramic materials has remained the longstanding obstacle for the materials to be utilized in high-temperature piezoelectric devices. Herein, a strategy to defer thermal depolarization is employed. To acquire the best merits of two different materials, 0-3 type CaBi2Nb2O9:xwt%BiFeO3 (CBN:xwt%BFO) composites are engineered in a unique way by embedding the isolated BiFeO3 (BFO) grains at the grain boundaries of the CaBi2Nb2O9 (CBN) matrix. The composite with 0-3 type connectivity (CaBi2Nb2O9:40wt%BiFeO3) exhibits a high density of 7.98 g/cm(3), a high saturated polarization of similar to 19 mu C/cm(2), high resistivity of similar to 10(10) omega.cm, and an enhanced piezoelectric coefficient d(33) of 29 pC/N at room temperature. Composite shows the sharp-peaked ferroelectric-paraelectric transition at high Curie temperature T-C of similar to 881 degrees C. Importantly, the composite maintains a very high resistivity of similar to 10(5) omega.cm even at 500 degrees C and the d(33) of 24 pC/N after annealing at 700 degrees C. Moreover, the poled composite has displayed strong radial and thickness dielectric resonances at 20-700 degrees C. Concluding the results, the CBN:40 wt%BFO composite with 0-3 type connectivity shows the stable high-temperature piezoelectric response much better than either CBN or BFO and is the worthier candidate to be utilized in high-temperature piezoelectric devices.