Role of conducting polyaniline interphase on the low field magnetoresistance for LSMO-PANI nanocomposites

The aim of the present report is to show the synergistic effect of conducting polyaniline and manganite nanoparticles on the low field magnetoresistance response. We specially focused on the role of the conducting polyaniline interphase in a broad range of temperatures and low applied magnetic fields. Our results showed an increment on the electrical conductivity and enhancement on the magnetoresistance for lower amounts of conducting polyaniline additions with respect to the manganite unloaded samples. We also found that close to room temperature, the changes in magnetoresistance are mostly due to an increment of the spin polarization and spin disorder due to the presence of polyaniline interphase. However, at intermediate temperatures the polyaniline interphase intrinsic magnetoresistance showed an additional contribution to the total negative magnetoresistance response. These results, suggest that conducting polymer interphase shows both passive and active roles in the enhancement of the low field magnetoresistance of inorganic-organic nanocomposites.