Structural, transport and magnetic properties of Sr2-xNdxFeMoO6 (0 <= x <= 1)

Ever since the discovery of pronounced colossal magnetoresistance (CMR) in manganites, the search for new classes of magneto resistive materials has been pursued. SrFeMoO6, a ferromagnetic material with magnetic transition temperature above 400 K, has been one of them. It has a double perovskite structure and is half-metallic in nature. Here we report structural, electronic and magnetic properties of Sr2-xNdxFeMoO6 series of compounds in which Sr2+ is substituted with Nd3+, a rare earth magnetic ion, over the range 0 <= x <= 1. The substitution of higher valance ion Nd3+ in place of Sr2+ results in electron doping of the system. Samples of all the compositions were observed to be of single phase, ascertaining the solid solubility of Nd into the system over the entire range explored. The effect of substitution on the ordering of Fe and Mo atoms revealed that the amount of order in the system decreased with increasing substitution. The low-field magneto resistance of the samples was found to drop sharply with substitution and become negligible for samples with higher amount of substitution. With increasing substitution even though the saturation magnetization decreases as expected from the increasing disorder in the system, the magnetic ordering temperature remains almost constant. (c) 200