Dielectric relaxation in (Ba_(0.7)Ca_(0.3))TiO_3-Ba(Zr_(0.2)Ti_(0.8))O_3 ceramics

摘要

In this work, effect of low sintering temperature and time on the new lead-free perovskite (Ba_(0.7)Ca_(0.3))TiO_3-Ba(Zr_(0.2)Ti_(0.8))O_3 (BCZT) solid solution ceramics have been investigated. X-ray diffraction (XRD) was used to understand the phase transition of the BCZT during heating. The Curie temperature decreased nonlinearly 43 K in BCZT ceramics. Diffuse phase transitions were observed in BCZT ceramics and the Curie-Weiss exponent (CWE) was nearly 2. The dielectric permittivity versus temperature characteristics and the γ in the modified Curie-Weiss law, as a function of the dc bias field was obtained for BCZT ceramics. The fitting of parameters (T_m vs. f) have close agreement with the data of Vogel-Fulcher's relationship.