Physicochemical properties of rare earth doped ceria Ce0.9Ln0.1O1.95 (Ln = Nd, Sm, Gd) as an electrolyte material for IT-SOFC/SOEC

Nanosized crystallites of rare earth doped ceria Ce(0.9)Ln(0.1)O(1.95) (Ln = Nd, Sm, Gd) a promising electrolyte material for Intermediate Temperature - Solid Oxide Fuel Cells/electrolysis cells have been synthesized by standard ceramic route. Detection of impurities in the samples was done by FTIR spectroscopy. X-ray diffraction studies were used for the determination of phase purity, crystal structure and average crystallite size of the samples. Kinetics involved in phase formation has been discussed. Raman study showed a major band around 465 cm(-1) in all the samples, which is attributed to the cubic fluorite structure of ceria. It was also found that for samples Ce(0.9)Ln(0.1)O(1.95) (Ln = Nd, Sm, Gd) the frequency of F-2g shifts to lower value. Electrochemical impedance spectroscopy has been used to measure the ionic conductivity of the samples at elevated temperatures. The Gd doped sample showed the highest grain boundary and total conductivity in comparison to Sm and Nd doped sample. Bulk thermal expansion behavior, sintered densities and micro structural features of the samples have also been studied. (C) 2013 Elsevier Masson SAS. All rights reserved.