Strontium dopant concentrations influence on Nd_1-xSr_xMnO_3±δ structural and electrical conductivity

Many different types of ceramic materials are currently being studied as possible cathodes in Solid Oxide Fuel Cells (SOFC), in an attempt to reduce operating temperatures. Strontium-doped neodymium manganite (Nd_1-xSr_xMnO_3±δ) was used as an intermediate temperature solid oxide fuel cell cathode. X-ray diffraction and electrical conductivity of the Nd_1-xSr_xMnO_3±δ system with a perovskite structure were studied in function of x equal to 0.10, 0.30 and 0.50. An orthorhombic pseudo perovskite structure was assigned to all powder compositions prepared by standard ceramic technique. Electrical conductivity was described by the small polaron hopping conductivity model, as well as, increases due to regular increments of Sr content for all compositions. Electrical conductivity was measured at 25.2, 26.4 and 37.1Scm^-1 for x = 0.10, 0.30 and 0.50, respectively at 800 deg C. (author)