Characterization, electrical and magnetic properties of polyaniline/maghemite nanocomposites

Composites of polyaniline with nanocrystalline maghemite capped with oleic acid were synthesized at various maghemite loadings and their electrical and magnetic properties were studied from 5 to 300 K. Chemisorption of oleic acid by the surface iron atoms provided excellent dispersion of maghemite in organic solvents and thus enabled their homogenous dispersion in the polymer matrix. The resulting nanocomposite materials exhibit properties of both the conductive matrix and the magnetic iron oxide component. Magnetoresistance studies indicated an increase in the resistance in the presence of an external magnetic field, while the absolute conductivity values decrease due to the addition of iron oxide nanoparticles.