SHAN Ke^1,2, ZHAI Fengrui^1,2, LI Nan^1,2, SUN Lida^1,2, ZHOU Pengfei ¹, YI Zhongzhou^1,2, XIE Zhipeng³
((1. College of Science, Honghe University, Mengzi 661199, Yunnan, China; 2. Local Characteristic Resource Utilization and New
Materials Key Laboratory of Universities in Yunnan, Honghe University, Mengzi 661199, Yunnan, China; 3. State Key Laboratory of
New Ceramics and Fine Processing, Tsinghua University, Beijing 100084, China)

Abstract: YSZ-SrTi_0.6Fe_0.4O_3-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.

Key words: YSZ-SrTi_0.6Fe_0.4O_3-δ , relaxation; impedance spectra; frequency spectra