文献类型：期刊文献

英文题名：Relative content of the Cr4+ ion and electrical conductivity of La0.75Ca0.25Cr0.75Fe0.25 O3

作者：Zhang, G.J.[1]; Xiong, H.[1]; Zheng, J.Y.[1]; Jia, Y.Q.[1]; Xuan, Y.[2]; Mizutani, Nobuyasu[2]

机构：[1] Department of Chemistry, East China University of Science and Technology, Shanghai 200237, China; [2] Department of Inorganic Materials, Tokyo Institute of Technology, Tokyo 152, Japan

年份：2001

卷号：71

期号：1

起止页码：84

外文期刊名：Materials Chemistry and Physics

收录：EI(收录号：2001336615079)

语种：英文

外文关键词：Activation energy - Chromium - Doping (additives) - Electric conductivity of solids - Oxygen - Synthesis (chemical) - Thermal effects - Thermodynamics

摘要：La0.75Ca0.25Cr0.75Fe0.25 O3 is synthesized by a wet chemical method and the electric conductivity of the compound in air is measured over a temperature range from 296 to 1083 K. Arrhenius plot for La0.75Ca0.25Cr0.75Fe0.25 O3 is composed of two line segments and the discontinuity is at 532 K. The approximate calculation for the temperature dependence of the electrical conductivity of the compound has been performed in consideration of the thermodynamic equilibrium between the Cr3+ and Cr4+ ions in the compound. The electrical conductivity of lanthanum chromite is directly proportional to the relative content of the Cr4+ ion in the compound and the relative content of the Cr4+ ion in La0.75Ca0.25Cr0.75Fe0.25 O3 increases with temperature. The activation energy and the electron hopping frequency may have more significant effect on the electric conductivity of the compound. The occurrence of the oxygen deficiency in the doping lanthanum chromite can be explained by the calculated results. ? 2001 Elsevier Science B.V.