HIGH TEMPERATURE PIEZOELECTRIC PROPERTIES OF SOME BISMUTH LAYER-STRUCTURED FERROELECTRIC CERAMICS

摘要

We focused on some BLSF ceramics with high Curie temperature, T_c such as Bi_4Ti_3O_(12) (BIT), Na_(0.5)Bi_(4.5)Ti_4O_(15) (NBT), CaBi_4Ti_4O_(15) (CBT4) and CaBi_2Ta_2O_9 (CBT2), and examined their piezoelectric properties at room temperature. As results, Bi_4Ti_(0.98)V_(0.02)O_(12) (BITV-0.02) indicated relatively high 7c of 678℃ and the largest piezoelectric voltage constant, g_(33), of 22×10~(-3) Vm/N among above compounds. The grain oriented BITV-0.02 indicated large g_(33) ～35×10~(-3) Vm/N at room temperature and g_(33) ～27× 10~(-3) Vm/N at 400℃ from the in-situ measurement of resonance and antiresonance method. Therefore, the BITV-0.02 ceramic seems to be good candidate for lead-free high-temperature piezoelectric materials.