Study of ferromagnetic-metal type Sr2FeMoO6 + xAg (x = 0–10 wt%) composites

Abstract

Ferromagnetic-metal type Sr2FeMoO6+xAg (x=0, 1, 2, 3, 5 and 10wt%) composites were synthesized by standard solid-state reaction method and studied their structural, magnetic and magneto-transport properties. The X-ray diffraction (XRD) pattern shows the XRD peaks corresponding to both Sr2FeMoO6 (SFMO) and metallic Ag phases, which indicates the successful formation of composites. High resolution field emission scanning electron microscope (FESEM) with energy dispersive X-ray spectroscopy (EDS) analysis also reveals the coexistence of both the phases in composite. It is also clear from FESEM images that the smaller size Ag particles reside over the grain surface/boundaries of SFMO grains. Dramatic decrease in electrical resistivity with the addition of Ag in the composites has been observed in the entire measured temperature range from 300–20K. Moreover, a systematic decrease in low field magnetoresistance (LFMR) is also observed as we increased the Ag content. This decrement in LFMR values of these composites is mainly due to the presence of metallic Ag at the grain surface/boundaries of SFMO, which suppresses the spin polarized tunneling and finally reduces the magnetoresistance.