两步烧结法制备BiFeO_(3)-(Ba_(0.85)Ca_(0.15))(Zr_(0.10)Ti_(0.9)0)O_(3)陶瓷的性能研究

Properties of BiFeO_(3)-(Ba_(0.85)Ca_(0.15))(Zr_(0.10)Ti_(0.90))O_(3)Ceramics Prepared by Two-Step Sintering Method

在BiFeO 3中引入钙钛矿氧化物(Ba_(0.85)Ca_(0.15))(Zr_(0.10)Ti_(0.9)0)O_(3)可有效改善陶瓷的铁电性能,但采用传统固相法制备陶瓷时烧结温度高,导致材料内部缺陷较多。本文利用高温(T_(1))短时烧结和低温(T_(2))长时保温的两步烧结法,研究T 1对0.7BiFeO_(3)-0.3(Ba_(0.85)Ca_(0.15))(Zr_(0.10)Ti_(0.9)0)O_(3)-0.15%(质量分数)MnCO_(3)(简写为0.7BF-0.3BCZT)陶瓷相组成、微观结构、铁电和介电性能的影响。结果表明:所制备的陶瓷为纯相,其相结构为菱方和赝立方相共存。随着T 1的升高,陶瓷的密度、介电常数和剩余极化强度呈先增加后降低趋势。在T 1=1040℃时,陶瓷具有最优的介电和铁电性能,此时最大介电常数和剩余极化强度分别为6706.10和8.53μC/cm^(2)。

The ferroelectric property of ceramics can be significantly improved by adding(Ba_(0.85)Ca_(0.15))(Zr_(0.10)Ti_(0.9)0)O_(3)into BiFeO 3.However,the sintering temperature of ceramics prepared by traditional solid-state method is high,resulting in increasing internal defects of ceramic materials.In this study,0.7BiFeO_(3)-0.3(Ba_(0.85)Ca_(0.15))(Zr_(0.10)Ti_(0.9)0)O_(3)-0.15%(mass fraction)MnCO_(3)(abbreviated as 0.7BF-0.3BCZT)ceramics were sintered using the two-step sintering method based on the short-term sintering at high temperature(T_(1))and long-term holding at low temperature(T_(2)).The effect of T_(1)temperature on the phase composition,microstructure,ferroelectric and dielectric properties of as-prepared ceramics was investigated.The results reveal that the phase structures of as-prepared ceramics are coexistence of rhombohedral and pseudo-cubic phases with no evidence of secondary phase.With the increase of T_(1)sintering temperature,the bulk density,dielectric constant and remanent polarization of ceramics increase first and then decrease.Consequently,the ceramics prepared at T_(1)=1040℃demonstrate excellent dielectric and ferroelectric properties.The maximum dielectric constant and remanent polarization are 6706.10 and 8.53μC/cm^(2),respectively.