Structure, dielectric, and ferroelectric properties of Ba_(0.85)Ca_(0.15)Zr_(0.1)Ti_(0.9) O_3 ceramics sintered at various temperatures

摘要

The Ba_(0.85)Ca_(0.15)Zr_(0.1)Ti_(0.9) O_3 (referred to as BCZT) ceramic powders were synthesized by the sol-gel method followed by calcining, and then the ceramics were obtained by sintering at different temperatures varied from 1200 to 1350 °C. The effects of sintering temperature on the microstructure, impedance spectroscopy, dielectric, and ferroelectric properties for BCZT ceramics have been thoroughly investigated. The pure perovskite structure and homogenous microstructure with high relative density (＞ 90%) for all BCZT ceramics are identified by XRD analysis and SEM measurement, and the stability is identified by the variable-temperature dielectric characterization. The impedance spectroscopy and well-defined polarization-electric field hysteresis loops for BCZT samples were detected at room temperature. In particular, the BCZT ceramic sintered at 1300 °C resulted the highest dielectric constant (ε_r～2170), the lowest dielectric loss (tan δ～ 0.027), and the highest grain boundary resistance (R_(gb)～ 8.9× 10~7 Ω cm).