Synthesis of nano-crystalline Ce0.9Gd0.1O1.95 electrolyte by novel sol-gel thermolysis process for IT-SOFCs

Abstract

In the present work, nano-crystalline Ce0.9Gd0.195 (GDC) powder has been successfully prepared by a novel sol-gel thermolysis method using a unique combination of urea and PVA. The gel precursor obtained during the process was calcined at 400 and 600 C for 2 h. A range of analyzing techniques including XRD, TGA, BET, SEM, EDS and TEM were employed to characterize the physical and chemical properties of obtained powders. GDC gel precursors calcined at 400 and 600 degrees C were found to have an average crystallite size of 10 and 19 nm, respectively. From the result of XRD patterns, we found that well-crystalline cubic fluorite structure GDC was obtained by calcining the precursor gel at 400 and 600 degrees C. It has been also found that the sintered samples with lower temperature calcined powder showed better sinterability as well as higher ionic conductivity of 2.21 x 10(-2) S cm(-1) at 700 degrees C in air. (c) 2008 Elsevier Ltd. All rights reserved.