Elaboration and characterization of the Sr 2FeMoO6 double perovskite

AbstractIn this work the structural and magneto-transport properties of the Sr 2 FeMoO 6 double perovskite prepared using two elaboration processesare presented. The first process is the most used solid-state reaction technique starting from three materials: Fe 2 O 3 , SrCO 3 and metallic MoO 3 with the appropriate amounts. For this process, treatment conditions have been optimized in order to reduce the SrMoO 4 amounts in the finalcompound. The best results have been obtained after annealing the mixture during 1h at 700 ◦ C under reducing 5% H 2 –95% N 2 atmospherefollowed by calcinations at 1200 ◦ C under Ar atmosphere during 10h. X-ray diffraction measurements have shown that the phase can beindexed within the I4/mmm space group indicating a tetragonal distortion. The magneto-transport measurements have shown the highestsaturation magnetization value reaching 26.7emu/g at 300K and a magnetoresistance (MR) of 2.5%. For the second process, the phase hasbeen elaborated using several steps and reacting at each step only two materials. In this case X-ray diffraction shows that the final compoundis a single phase with the same space group as for the previous one. In contrast, the saturation magnetization is slightly smaller with 21emu/g,while, at the opposite, the magnetoresistance is higher reaching 3.6%. These results will be discussed in correlation with the structural results.© 2004 Elsevier B.V. All rights reserved.