On the temperature dependence of ferrofluid susceptibility

Abstract

The fulfillment of Curie-Weiss laws for a ferrofluid is critically discussed. The results of investigations of the magnetic susceptibility temperature dependences of ferrofluid and dried powder of magnetic particles are presented. The effective field parameter is computed in approximation of the effective field theory. It is indicated that the value of the effective field parameter is not constant and depends on the concentration of magnetic nanoparticles and the temperature of the sample. It was found that Curie-Weiss law with λ = 4π/3 is satisfied for ferrofluid with a limited range of volume concentration of magnetic particles