Magnetic And Magnetotransport Properties Of Sr2fe1-Xcrxmo1-Xwxo6 Double Perovskite Compounds Prepared By The Encapsulation Technique

Sr2Fe1-xCrxMo1-xWxO6, x = 0, 0.05, 0.10, 0.15, 0.20, and 0.30 compounds have been prepared by the solid state encapsulation technique and their magnetic and magnetotransport properties have been studied. All samples show ferromagnetism at room temperature, the Curie temperature increases with x up to x = 0.10 (T-C = 426 K), remaining at high values even for x = 0.30 (T-C = 408 K). The resistivity of the low-doped (x < 0.10) as prepared compounds is the lowest reported in the literature for bulk samples at room temperature, but the low-field magnetoresistance is poor due to the lack of an appreciable insulating grain boundary layer in these samples. Enhancement of the low-field magnetoresistance is observed after post-annealing, due to modification of the composition of the grain boundary layer. (c) 2007 Elsevier B.V. All rights reserved.