Giant magnetoresistance in composites of organic polymers with manganese acetylacetonate and lanthanum-praseodymium chlorides exhibiting ionic conductivity.

We present a new giant magnetoresistance (GMR) material composed of polyaniline, polystyrene, sulfur, manganese acetylacetonate, lanthanum, and praseodymium chlorides. These compounds were mixed and processed mechanochemically to obtain thin films. External magnetic field of 6000 Oe increases conductivity of films by more than 300%. Analysis of transient current kinetics after application of constant voltage (10 V) to samples showed the existence of three types of charge carriers, which we identified as e-, H+, and Cl-. Contribution of functional groups of polyaniline and elemental sulfur S in the formation of the above charge carriers in this new GMR composite material is discussed. [ABSTRACT FROM AUTHOR]