Lead-free piezoelectric ceramics based on (Bi_1/2Na_1/2)TiO₃-NaNbO₃

Abstract

Abstract Dielectric, ferroelectric and piezoelectric pŕoperties of a BNT-based solid solution, (1-x)(Bi1/2Na1/2)TiO3-xNaNbO3, that is, Bi(1-x)/2Na(1+x)/2 Ti1-x Nb x O3 (BNTN-100x), are studied from the viewpoint of a new group of lead-free piezoelectric ceramics. The conventional ceramic fabricating technique was used to prepare BNTN ceramics. D-E hysteresis loops could be easily observed with a relatively large remanent polarization, P r, of about 25∼33 μC/cm2 and a high coercive field of about 50 kV/cm near the composition of BNT side. The electromechanical coupling factors, k p, k t, and k 33 were about 0.108, 0.424 and 0.433 for BNTN-3. BNTN ceramics seem to be a candidate for lead-free piezoelectric ceramics.