0.7BiFeO_(3)-0.3BaTiO_(3)压电陶瓷的工艺优化及其电学性能

Preparation Process Optimization and Electrical Properties of 0.7BiFeO_(3)-0.3BaTiO_(3)Piezoelectric Ceramics

基于铁酸铋基陶瓷在压应力作用下产生感应电荷的压电转换特性,通过调控预烧温度、预烧次数和烧结温度3个影响因素,优化陶瓷制备工艺对陶瓷介电损耗和剩余极化强度等的影响,从而改善其压电性能,确定0.7BiFeO_(3)-0.3BaTiO_(3)陶瓷制备工艺的最佳条件:预烧温度730℃,预烧次数2次,预烧时间5 h,烧结温度984℃,制得陶瓷的压电常数为152 pC/N,比优化前提高了15.4%;剩余极化强度为29.16μC/cm 2,比优化前提升了42.3%;优化后的陶瓷样品为三方-四方(R-T)共存的纯钙钛矿相结构,成瓷性好,晶粒大小分布均匀且晶粒尺寸有所增大,介电损耗较优化前降低了14.3%。陶瓷制备工艺的改进显著优化了陶瓷的高温漏导和极化特性,从而提升了其压电性能。

In this work,since bismuth ferrite-based ceramics generated induced charge at their surfaces under pressure,the optimum process of 0.7BiFeO_(3)-0.3BaTiO_(3) ceramic was studied.Though regulating the three influencing factors of calcination temperature,calcination times and sintering temperature,the effects of process on dielectric loss and remanent polarization of ceramics were explored to improve the piezoelectric properties.The optimum process conditions of 0.7BiFeO_(3)-0.3BaTiO_(3) ceramic were determined as follows:the calcination temperature was 730℃,the calcination frequency was twice,the calcination time was 5 h,and the sintering temperature was 984℃.The piezoelectric constant of the prepared ceramics was 152 pC/N,which was 15.4%higher than that before optimization.The remanent polarization was 29.16μC/cm 2,which was 42.3%higher than that before optimization.After the optimization,the ceramic sample performed coexistences of R and T phases,good characteristics of porcelain,the grain size was evenly distributed and increased,while the dielectric loss was reduced by 14.3%compared with that before optimization.The improvement of the process significantly optimized the characteristics of high temperature leakage conductance and polarization,thus improving the piezoelectric properties.