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

Abstract

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.

Magnetic behaviors and enhanced magnetoresistance in granular (La0. 7Pb0.3MnO3)1−x(Fe2O3)x composites

“…Recently, researches indicate that grain boundaries and interfaces can be the major factors of magnetoresistance effects, which has attracted renewed interests on these materials. The enhancement of MRR through the composites of La 1-x Sr x MnO 3 /CeO 2 , La 1-x Sr x MnO 3 /silica and La 1-x Sr x MnO 3 /glass has been reports [6][7][8]. These enhancements can be explained through the model of spin-polarized tunneling with insulator layer as a barrier.…”

Magnetic phase boundary and transport properties of La0.67Ca0.33MnO3

“…There are some other extrinsic magnetoresistance (MR) effects, such as grain boundary MR, spin-polarized transport MR in ferromagnetic tunnelling junctions, and domain wall MR [4]. These MR effects have been observed in granular composites of LSMO/CeO 2 [5] and LCMO/SrTiO 3 [6]. In these composites, an enhanced LFMR effect was observed near a percolation threshold x C .…”

Enhanced electro-magnetic properties in La0.7Sr0.3MnO3/ZrO2 composites

“…Recently, another type of magnetoresistance (MR) has been found in polycrystalline manganites. This kind of MR is mainly dependent on the grain boundary properties and the spin-polarized tunneling of conduction electrons [7] and it usually occurs over a wide temperature range and at a low magnetic field. Hence, it's called as LFMR, which is associated with the spin-memory contribution to charge transport across the grain boundary (or interface) by modifying the microstructure of the manganites.…”