Influence of non-magnetic ion In3+ on the magneto-transport properties in La0.7Bi0.05Sr0.15Ca0.1Mn1-xInxO3 (0 ≤ x ≤ 0.3) perovskite

In this work, the polycrystalline La0.7Bi0.05Sr0.15Ca0.1Mn1-xInxO3 (0= x= 0.3) have been prepared by the Pechini-sol-gel method. A significant improvement in magnetoresistance (MR) has been observed from 64% for x = 0-84% for x= 0.3 at a magnetic applied field of 5T. Analysis on the measured electrical resistivity data indicates that for T below metal - semiconducting transition temperature (TM-Sc), the resistivity was described by a phenomenological percolation model which is based on theory on electron-electron, electron-phonon scattering. However, for T above TM-Sc, two conduction models are explored to describe the transport behaviors: the Mott's variable range hopping (VRH) model and the small polaron hopping model (SPH).