Enhanced room-temperature magnetoresistance in La0.7Sr0.3MnO3-glass composites

In this letter, we report the improved magnetotransport properties of La0.7Sr0.3MnO3-borosilicate glass composite with different weight percents of glass. All the composites showed ferromagnetic nature at room temperature. The microstructure of these composites was seen using a scanning electron microscope. The microstructure was reconfirmed using spot energy dispersive x-ray analysis. We observe an enhancement of the low-field magnetoresistance (<200 Oe) at room temperature for the optimal composition of 25 wt % of glass. It is argued that glass layer separating the grain boundaries may be acting as barrier for spin-polarized tunneling, thereby enhancing the low-field magnetoresistance.