Enhancement in Curie temperature and reduction in magnetoresistance of Sr2(Fe1-xNix)MoO6 (0≤x ≤0.15)

The polycrystalline Sr-2(Fe1-xNix)MoO6 (0 <= x <= 0.15) samples with ordered double perovskite structure were prepared by solid-state reaction process. Structural, magnetic and magneto-electrical transport properties have been studied systematically. The X-ray diffraction results show gradual decrease in degree of cationic order with increasing Ni content and increase in the anti-site defects. The Curie temperature (T-C) in the Sr-2(Fe1-xNix)MoO6 is enhanced systematically from 408 K for x=0 to 424 K for x=0.15. However, magnetization is observed to decrease with increasing Ni content. The resistivity of all the samples exhibits semiconducting behavior in measured temperature range (80-300 K). The low field magnetoresistance is observed to decrease with increasing the Ni concentration. The observed decrease in low field magnetoresistance has been attributed to the increased disorder and anti-site defects. (c) 2007 Elsevier B.V. All rights reserved.