화학공학소재연구정보센터
Solid State Ionics, Vol.180, No.11-13, 872-877, 2009
Influence of various lanthanides on the properties of Sr(0.8)Ce(0.1)Ln(0.1)MnO(3-delta) and Sr(0.9)Ce(0.05)Ln(0.05)CoO(3-delta) ceramics and thick film electrodes
In this work nonstoichiometric strontium cerium manganites and cobaltites Sr(0.8)Ce(0.1)Ln(0.1)MnO(3 - delta) and Sr(0.9)Ce(0.05)Ln(0.05)CoO(3 - delta) with low content of various lanthanides (Ln = La, Ce, Nd, Sm, Gd, Dy, Yb) were investigated as potential electrode materials for solid state fuel cells and gas sensors. Synthesis and sintering conditions as well as dc resistivities and thermal expansion coefficients of the developed ceramics in the range 20-900 degrees C were studied. On the basis of complex impedance spectroscopic studies of yttria stabilized zirconia solid electrolyte samples with thick film perovskite electrodes four contributions to the dielectric response were found, attributed to the grains and the grain boundaries of the solid electrolyte, to the electrode-electrolyte interface and to the electrodes. in the descending order of frequency. Dc conductivity of the ceramic samples and thick films exhibited semiconducting, semimetallic or metallic character, depending on the composition and the examined temperature range. In the temperature range of 600-900 degrees C, a very good agreement was found between the experimental and the theoretical values of electromotive force of concentration oxygen cells based on zirconia solid electrolyte with perovskite electrodes. (C) 2009 Elsevier B.V. All rights reserved.