High Temperature Piezoelectric Properties of Vanadium Doped Bi4Ti3O12 Ceramics with Grain Orientation

The grain orientation effects of Bi4Ti0.98V0.02O12 [HF-BITV-0.02] ceramics were investigated using the hot-forging (HF) method for their piezoelectric properties and the high temperature piezoelectric characteristics were examined. Piezoelectric properties of electromechanical coupling factor, k33, piezoelectric strain constant, d33, piezoelectric voltage constant, g33 and mechanical quality factor, Qm at room temperature were 0.39, 40.1 pC/N, 34.5 10- 3 Vm/N and 1500, respectively. The HF-BITV-0.02 indicates both high Curie temperature, Tc (= 678C) and high g33 value as compared with other high temperature piezoelectric materials. From the measurement of piezoelectric properties after the thermal annealing at 550C, the k33 and Qm are revealed to keep high values of approximately 0.37 and 1300, respectively, without a depolarized degradation up to 550C. The real time temperature dependences of piezoelectric properties indicate a good resonance and antiresonance curve and the k33 higher than 0.37 at 400C. Therefore, the HF-BITV-0.02 ceramics seem to be good candidate for lead-free high-temperature piezoelectric materials.