Preparation and Properties of Bi0.5Na0.5TiO3-Ba (Hf,Ti)TiO3 Lead-Free Piezoelectric Ceramics
Lead-free piezoelectric ceramics based on bismuth sodium titanate (BNT) -barium hafnate titanate (BHT) were prepared by a two-step synthesis process. The final BNT-BHT ceramics sintered at 1180oC for 2 h in air showed a perovskite structure with high density. The morphotropic phase boundaries (MPB) were found in BNT based piezoelectric ceramics with 8~10 wt% BHT in composites. In the case of Bi0.5Na0.5TiO3-0.08BaHf0.05Ti0.95O3 ceramics, a maximum piezoelectric coefficient d33 of 122.6 pC/N was obtained. The remnant polarization (Pr) and coercive field (Ec) were measured and the relationship between ferroelectricity and the BHT fraction in the compounds was investigated. The BNT-BHT ceramics were expected to be a new and promising candidate for lead-free piezoelectric device applications.
J.K. Kim, D.Z. Wo, L.M. Zhou, H.T. Huang, K.T. Lau and M. Wang
H. Y. Tian et al., "Preparation and Properties of Bi0.5Na0.5TiO3-Ba (Hf,Ti)TiO3 Lead-Free Piezoelectric Ceramics", Key Engineering Materials, Vols. 334-335, pp. 957-960, 2007