Room temperature low field magnetoresistance in Sr2FeMoO6/ZnxFe1-xFe2O4 composites

Double perovskite Sr2FeMoO6/ZnxFe1-xFe2O4 (SFMO/ZFO) composite systems with varying zinc content in nanosized zinc ferrite were synthesized. Composites have been prepared by two phase sintering process of limited intermixing of the SFMO calcined powder and ZFO nanoparticles. The structural analysis confirms the coexistence of both the phases in the composites and revealed that the agglomerated ZFO nanoparticles segregated at the grain boundaries. It was found that the inclusion of low ZFO content (2wt. %) increases the resistivity, magnetization, and low field magnetoresistance (LFMR), whereas it further decreases with increasing ZFO content. A large room-temperature tunnelling magnetoresistance (Delta rho/rho(0)) ratio 4.83% and 6.90% was observed for pristine SFMO and SFMO/ZFO (x = 0.7) composite samples respectively at low magnetic field of 2 kOe, which is 1.42 times larger than pure SFMO sample. The enhanced LFMR is highly desirable for room temperature magneto resistive applications. (C) 2013 AIP Publishing LLC.