XPS and impedance spectroscopy of Gd doped CeO2 superionic ceramics

Abstract

Ce0.9Gd0.1O1.95 (CGO-10) and Ce 0.8Gd0.2O1.9 (CGO-20) ceramics have been sintered by using commercial powders of Fuel Cell Materials company. The powders of different surface area (BET [m2/g]) were used to prepare the ceramics. Elemental compositions of CGO solid electrolytes' surfaces have been investigated in 10-7 Pa vacuum by X-ray photoelectron spectroscopy and the ratio Ce4+/Ce3+ has been estimated. Electrical parameters of CGO ceramics were investigated in the frequency range from 1 MHz to 1.2 GHz. Temperature-dependant bulk ionic conductivity (σb,) was found to follow the Arrhenius law. Ionic conductivity of CGO-10 was higher compared to that of CGO-20. The bulk ionic conductivity of CGO-10 ceramics slightly depended on the grain size of initial powder. © Lithuanian Physical Society, 2009.