烧结温度对Sr_2Bi_5FeTi_5O_(21)铁电陶瓷性能的影响

Effect of Sintering Temperature on Properties of Sr_2Bi_5FeTi_5O_(21) Ferroelectric Ceramics

用溶胶-凝胶法制备出Sr_2Bi_5FeTi_5O_(21)(简称SBFTi)铁电陶瓷,研究了烧结温度对SBFTi铁电陶瓷的相结构、微观形貌、铁电性能和介电性能的影响。结果表明,在1090℃下烧结的铁电陶瓷样品是以SBTi晶相为主的钙钛矿结构,a轴择优取向度较高;晶粒发育完全,球形晶粒与片层状晶粒融合较好;铁电性能较好,其剩余极化强度2Pr达到了20.5μC/cm^2、矫顽场2Ec为128 kV/cm;在0.02 Hz^1 MHz频率范围内,其介电常数为147~164,介电损耗为0.012~0.030,具有较好的频率稳定性。

Sr_2Bi_5FeTi_5O_(21)(SBFTi) ferroelectric ceramic samples were prepared by a Sol-gel method. Effects of different sintering temperatures on the crystal structure, microstructure, ferroelectric properties and dielectric properties of the SBFTi ferroelectric ceramics were studied. It is found that the ceramic samples sintered at 1090 ℃ exhibit perovskite structure with Sr2Bi4Ti5O18(SBTi) and present a-axis orientation. The grains develop entirely and small spherical grains are distributed in large pieces leafy grains. The samples show excellent ferroelectric properties at this sintering temperature. The highest remnant polarization 2Pr and coercive field 2Ec are 20.5 μC/cm^2 and 128 k V/cm, respectively. Its dielectric constant ranges from 147 to 164 and dielectric loss is from 0.012 to 0.030 within 0.02 Hz^1 MHz frequency, indicating good frequency stability.