New approach to closely-spaced disordered cobalt-graphene nanocomposites for non-conductive ferromagnetic films: From local structure to radio-electric properties

Nanocrystalline magnetic thin films have attracted considerable attention since they show unique properties that hold great potential for Information Communication Technologies (ICT). Solid-state magnetic materials have long existed in two categories: conductive metals with large magnetic moment and non-conductive oxides with low magnetization. In this work, non conductive magnetic nanocomposites made of metallic nanoparticles are considered as a major technological breakthrough. Indeed, dipolar magnetism with high moment nanoparticles promises to push the limits of solid-state magnetism if collective magnetic properties can be controlled in closely-spaced structures at nanoparticle level. In conventional materials, dipolar magnetism is negligible, as the magnetostatic interactions between neighboring atoms are too weak to explain magnetic ordering. In nanocomposites, the situation is reversed as the statement of strong exchange coupling and negligible dipolar interaction is no longer true.