Effects of Bi~(3+) doping of the dielectric and piezoelectric properties of Ba_(0.9)Ca_(0.1)Ti_(0.9)Zr_(0.1)O_3 ceramics prepared by hydrothermal method

摘要

Ceramics in the solid solution system, Ba_(0.9)Ca_(0.1)Ti_(0.9)Zr_(0.1)O_(3-x)Bi~(3+) (x = 0.000-0.030) were prepared by hydrothermal and were assisted by microwave sintering. Effects of Bi~(3+) content on the phase transition, micro-structure, and electrical properties of ceramics were investigated. The single phase perovskite-type ceramics showed different polymorphs and the grain size was significantly influenced with the doping of Bi~(3+). Dielectric measurements indicated excellent dielectric relaxation behavior for x = 0.005 and x = 0.030. At x = 0.015 and x = 0.020, samples show giant dielectric constant (near 200,000) and lower dielectric loss (lower than 1.2), compared with other giant permittivity materials such as CCTO. The relationship between T_C and 2E_C was investigated and a novel conclusion of the 2E_C was increased with increasing T_C was reached. A maximum value of d_(33) = 265 pC/N was observed at x = 0.025 for the emergence of T_(O-T). That is because piezoelectrics always possessed high d_(33) near morphotropic phase boundary.