Piezoelectric and Ferroelectric Properties of Li-Doped (Bi0.5Na0.5)TiO3–(Bi0.5K0.5)TiO3–BaTiO3 Lead-Free Piezoelectric Ceramics
Abstract:The piezoelectric and ferroelectric properties of 0.852[Bi0.5(Na(1−x)Lix)0.5]TiO3–0.110(Bi0.5K0.5)TiO3–0.038BaTiO3 (x=0, 0.02, 0.05, 0.10, 0.15, and 0.30, abbreviated as BNKLBTx) lead-free piezoelectric ceramics were prepared by conventional ceramic processing. X-ray diffraction on the samples revealed that Li+ ions diffused into the Bi0.5Na0.5TiO3 lattices (A-site) and formed a solid solution with a single perovskite structure. All the samples could be sintered at 1160°–1180°C, with the density being on the order of >95% of the theoretical. The ceramics with x=0.10 exhibited the highest properties, with the piezoelectric coefficient being on the order of d33=235 pC/N, while the electromechanical coupling factors were found to be kp=0.30 and kt=0.45, respectively. The dielectric, pyroelectric, electromechanical, and ferroelectric behaviors were investigated as a function of temperature. It was found that the depolarization temperature Td showed a strong dependence on the content of Li+ addition, shifting to a lower temperature with increasing Li+ dopant.
Document Type: Research Article
Affiliations: 1: Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802 2: The State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
Publication date: April 1, 2010