Critical dynamics of an interacting magnetic nanoparticle system

Abstract

Effects of dipole-dipole interactions on the magnetic relaxation have been\ninvestigated for three Fe-C nanoparticle samples with volume concentrations of\n0.06, 5 and 17 vol%. While both the 5 and 17 vol% samples exhibit collective\nbehavior due to dipolar interactions, only the 17 vol% sample displays critical\nbehavior close to its transition temperature. The behaviour of the 5 vol%\nsample can be attributed to a mixture of collective and single particle\ndynamics.\n