Intergrain magnetoresistance in electron-doped Sr/sub 2/FeMoO/sub 6/

Abstract

Electron-doped double perovskite compounds (Sr/sub 2-x/La/sub x/)FeMoO/sub 6/ (x=0.0, 0.5, 0.7) were synthesized by combustion synthesis using oxalic acid dihydrazide as fuel. There is an increase in Curie temperature (T/sub C/) with La substitution up to a value of 172/spl deg/C for (Sr/sub 1.3/La/sub 0.7/)FeMoO/sub 6/. The compound (Sr/sub 1.5/La/sub 0.5/)FeMoO/sub 6/ with increased T/sub C/ compared to the undoped sample, exhibits a intergrain magnetoresistance of about 3% in a field of 0.1 T. The presence of magnetoresistance in La-doped samples prepared by combustion synthesis is due to the increased number of intergrain tunnel barriers.