LAUSR

Abstract 10 mol% CaO stabilized ZrO 2 (CSZ) singly and doubly doped with various amounts of FeO 1.5 and TiO 2 was prepared by a co-precipitation method, and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), electrochemical impedance spectroscopy (EIS) and Hebb-Wagner method. The results show that relative densities of samples are above 97% and close to each other except CSZT 0.29 . FeO 1.5 single doping improves the grain-boundary conductivity, but decreases the bulk conductivity, while TiO 2 single doping decreases both the bulk and grain-boundary conductivities. FeO 1.5 and TiO 2 double doping increases the grain-boundary and bulk conductivities. The increase in bulk and total conductivities of doped CSZ is mainly due to the high relative density, which provides more migration pathway for O 2− , while the increase in co-doping is attributed to the scavenge effect of TiO 2 on the grain boundary. The electronic conductivities of all samples measured in air are low, being 10 −7 −10 −6  S cm −1 in the temperature range of 670–850 °C.