Electrical Properties of Grain Oriented Bi_4Ti_3O_(12)-based Ceramics for High Temperature Sensors

摘要

Grain-oriented Bi_4Ti_(2.92)Nb_(0.08)O_(12) (BITN) ceramics were prepared by hot-forging (HF) method. The grain orientation factor, F, of BITN ceramic determined by the Lotgering method were approximately 0.96. The resistivity, ρ, along the c-axis of HF-BITN ceramic is higher than that of the a,b-axis of HF-BITN and OF-BITN ceramics for the temperature range from 100 to 400°C. The p along the direction parallel to the c-axis is found to be about 10~9 Ω-cmat 400°C, which is about ten times larger than that of OF-BITN ceramics. From resonance and anti-resonance characteristics, electromechanical coupling factor, k_(24), was 0.026 at room temperature.