Magnetization dynamics of non-dilute ferrofluids

Abstract

The paper is devoted to the theoretical investigation of the magnetodipolar interparticle interaction effect on remagnetization dynamics in moderately concentrated ferrofluids. We consider a homogenous (without particle aggregates) ferrofluid consisting of identical spherical particles and employ a rigid dipole model, where magnetic moment of a particle is fixed with respect to the particle itself. In particular, for the magnetization relaxation after the external field is instantly switched off, we show that the magnetodipolar interaction leads to the increase of the initial magnetization relaxation time. For the complex ac-susceptibility ( ) ( ) ( ) i χ ω χ ω χ ω