Off-morphotropic-phase-boundary 74(Bi1/2Na1/2)TiO3 – 20.8(Bi1/2K1/2)TiO3 -
5.2BaTiO3 ceramics were fabricated at different sintering temperatures. It was
found out that as the sintering temperature increased, the volatilization of the A-site
elements was aggravated, thus generating the oxygen vacancies; meanwhile, the
tetragonality of the perovskite lattice was gradually reduced. Besides, the
temperature-dependent dielectric responses revealed that as the sintering
temperature was increased, the depolarization temperature Td decreased while the
Curie–Weiss point TC increased. It was suggested that the lattice distortion, other
than the oxygen vacancies, was the crucial factor in influencing the depolarization
temperature.
[Dependence of Depolarization Temperature on Cation Vacancies and Lattice
Distortion for Lead-Free 74(Bi1/2Na1/2)TiO3–20.8(Bi1/2K1/2)TiO3–5.2BaTiO3
Ferroelectric Ceramics. M.Zhu, H.Hu, N.Lei, Y.Hou, H.Yan: Applied Physics
Letters, 2009, 94[18], 182901