Low-field magnetoresistance up to 400 K in double perovskite Sr2FeMoO6 synthesized by a citrate route

• Samples of Sr2FeMoO6 are prepared using a citrate route under varying conditions.
• Magnetoresistive properties are improved and optimized.
• Low-field magnetoresitence values as large as 5% at 300 K/1 kOe are reported.
• Persistence of low-field magnetoresistance up to 400 K.

A wet-chemistry technique, namely the citrate route, has been used to prepare high-quality polycrystalline samples of double perovskite Sr2FeMoO6. We report on the evolution of magnetic and magnetoresistive properties of the synthesized samples as a function of three parameters (i) the pH of the starting solution, (ii) the decomposition temperature of the citrate precursors and (iii) the sintering conditions. The low-field magnetoresistance (LFMR) value of our best samples is as high as 5% at room temperature for an applied magnetic field of 1 kOe. Additionally, the distinguishing feature of these samples is the persistence of LFMR, with a reasonably large value, up to 400 K which is a crucial parameter for any practical application. Our study indicates that the enhancement of LFMR observed is due to a good compromise between the grain size distribution and their magnetic polarization.

The microstructure (left panel) and corresponding low-field magnetoresistance of one of the Sr2FeMoO6 samples synthesized in the course of this work.Figure optionsDownload as PowerPoint slide