New nanocomposites from polypyrrole including /spl gamma/-Fe/sub 2/O/sub 3/ particles: morphological and magnetic characterizations

Summary form only given. This subject deals with the inclusion of ferromagnetic /spl gamma/-Fe/sub 2/O/sub 3/ grains of a few nanometers into an electronically conducting polymer giving rise to a one step synthesized composite with a determined and modulated stoichiometry. The materials come in the form of powder, latex solution (chemical synthesis) or thin film (electrochemical synthesis). The theoretical treatment of the magnetism of the latter material in term of the magnetic properties of the grains and their possible modifications by the inclusion has been developped. The inclusion of the mesoscopic /spl gamma/-Fe/sub 2/O/sub 3/ particles leads to a fair dispersion in the polymer, with no magnetic modification of the particles. This has been evidenced by several techniques as Transmission Electron Microscopy, X-ray diffraction, and magnetization experiments. Concerning the polymer, its electrical conductivity as a function of temperature remains unchanged in the presence of the /spl gamma/-Fe/sub 2/O/sub 3/ grains.