Transport properties of BaCe0.85Y0.15O3−δ at closed-cycle refrigerator temperature

The electrical conducting properties of both hydrated and dehydrated BaCe0.85Y0.15O3−δ (barium cerate, BCY) were investigated at low temperature (473–203 K) by an AC impedance analyzer combined with a dielectric interface. For the BCY, the bulk and grain boundary conductivities were separated with the equivalent circuit model, and the bulk conductivity was approximately two orders of magnitude higher than the grain boundary conductivity. At very low temperature (203 K), a single semicircle was obtained in the impedance plot, whereas three distinct semicircles were plotted in modulus plot due to the three different resistance components in the system. The activation energy of bulk conductivity was 0.55 eV and 0.57 eV for the hydrated and dehydrated BCY samples, respectively.