Effect of glass boundaries on complex impedance and magnetoresistance of 99.5% La0.7Sr0.3MnO3-0.5% glass nanocomposite

We have investigated complex impedance spectroscopy and magnetoresistance(MR) of 99.5% La0.7Sr0.3MnO3 (LSMO)-0.5% Glass nanocomposite material. We suppose, thin Glass boundary is formed at LSMO surface where depinning of grain boundary(GB) domain walls take place, from GB pinning centres, on application of magnetic field(H). Moreover, on application of temperature, conducting electrons at glass interface gain more thermal energy which also lead to temperature dependent electrical relaxation of the system. However the composite become more insulating on glass addition due to presence of intergranular glass barrier between neiboring LSMO grains. But surprisingly, MR of the composite indicate formation of very efficient spin polarized tunnel barrier on addition of glass at room temperature.We have investigated complex impedance spectroscopy and magnetoresistance(MR) of 99.5% La0.7Sr0.3MnO3 (LSMO)-0.5% Glass nanocomposite material. We suppose, thin Glass boundary is formed at LSMO surface where depinning of grain boundary(GB) domain walls take place, from GB pinning centres, on application of magnetic field(H). Moreover, on application of temperature, conducting electrons at glass interface gain more thermal energy which also lead to temperature dependent electrical relaxation of the system. However the composite become more insulating on glass addition due to presence of intergranular glass barrier between neiboring LSMO grains. But surprisingly, MR of the composite indicate formation of very efficient spin polarized tunnel barrier on addition of glass at room temperature.