Superparamagnetism of transition metal nanoparticles in conducting polymer film

Abstract

Magnetic properties of transition metal ( cobalt, iron, nickel, manganese, chromium) nanoparticles prepared by ion-exchange method in the perfluorinated sulfo-cation polymeric membrane (MF-4SK) have been investigated. While manganese and chromium in MF-4SK exhibited paramagnetic properties, cobalt, iron and nickel particles showed superparamagnetic behaviors. Our experimental evidence suggests that cobalt, iron and nickel nanoparticles in the polymer film obey a single-domain theory. (C) 2004 Elsevier B.V. All rights reserved.