YSZ-SrTi0.6Fe0.4O3-δ复相陶瓷材料的交流阻抗

摘要

采用溶胶-凝胶法制备SrTi0.6Fe0.4O3-δ,通过掺杂少量YSZ制备YSZ-SrTi0.6Fe0.4O3-δ复相陶瓷.采用电化学工作站测试样品电子-离子混合传导及离子传导的阻抗谱和频谱特性,结果表明,YSZ-SrTi0.6Fe0.4O3-δ在电子-离子混合传导过程中存在三种不同的极化过程,分别来自于晶粒,晶界和电极/样品,通过等效电路对阻抗谱的拟合,活化能分别为0.16 eV,0.62 eV和0.42 eV,随温度的升高,晶粒弛豫不明显,样品电阻主要由晶界的极化过程控制;在离子传导过程中,只存在一个晶界弛豫过程,晶界弛豫随温度的升高而减小,试样的弛豫时间为～0.13-0.29 s.%YSZ-SrTi0.6Fe0.4O3-δ ceramic composite was synthetized by sol-gel method. Complex impedance and frequency spectra were investigated using an impedance analyzer. The result indicates that three polarization processes correspond to grain, grain boundary and sample/electrode, and the activation energies are 0.16, 0.62 and 0.42 eV respectively during the ion-electron mix-conduction. The resistances of mix-conduction and ion conduction are also predominantly influenced by grain boundary. The relaxation time of space charge polarization at grain boundary decreases with the rise in temperature and lies in the range～0.13-0.29 s during ion conduction process.