Synthesis of cobalt nanoparticles in polymeric membrane and their magnetic anisotropy

Abstract We systematically synthesized cobalt nanoparticles in the perfluorinated sulfo-cation membrane (MF-4SK) in aqua solution using ion-exchange method. The average radius of cobalt nanoparticles in the polymer film is determined to be 3.5±1.0 nm by TEM. FMR measurements show that the angle dependence of resonance field ( H r ) follows the characteristics of flat-plate magnetic film and the easy axis lies along the surface of the polymer film. The experimental results suggest that the magnetic anisotropy comes from magnetized polymer film containing Co nanoparticles.