用固相合成方法制备了Sr2Bi4Ti5O18铁电陶瓷,研究了烧结温度对Sr2Bi4Ti5O18铁电陶瓷相结构、显微结构、铁电性能和介电性能的影响,分析了相关机理。结果表明,在1150℃进行烧结,样品晶粒发育完全,晶粒a轴择优取向,铁电性能优良,剩余极化强度2Pr达到15.3μC/cm2、矫顽场强2Ec为103kV/cm;在100kHz-1MHz频率范围内,介电常数为176-168,介电损耗为0.027-0.025,具有较好的频率稳定性。
Bismuth-layered compound Sr2Bi4Ti5O18(SBTi) ferroelectric ceramic samples were prepared by solid-state reaction method.Effect of sintering temperature on crystal structure,microstructure and ferroelectric properties of the SBTi ferroelectric ceramics were studied.It is found that crystals developed entirely and a-axis orientation is enhanced for Sr2Bi4Ti5O(18) ferroelectric ceramics sintered at 1150℃.At this sintering temperature,the highest remnant polarization 2Pr and coercive field 2Ec of the ceramics are 15.3μC/cm~2 and 103kV/cm,respectively.These results can be explained as follows: Bismuth in the pseudo-perovskite blocks evaporates easily at high sintering temperatures that leads to oxygen vacancies.The dielectric constant and dielectric loss of SBTi is 176~168 and 0.027~0.025 measured at 100kHz~1MHz,respectively.