Temperature dependence of dynamic magnetic properties of superparamagnetic magnetite nanoparticles powder

Abstract The experimental study of the dynamic magnetic susceptibility of the powder of superparamagnetic nanoparticles of magnetite is presented. The powder has been obtained by removal (evaporation) of the liquid base of the magnetic colloidal solution (ferrofluid). The temperature dependences of the real and imaginary parts of the magnetic susceptibility at different frequencies of the measuring field have been obtained. The experimental findings are compared with the results of the simulations based on the numerical solution of the Landau-Lifshitz-Gilbert equation for the interacting superparamagnetic nanoparticles system. The conclusion has been made on the significant influence of the interparticle interactions on the magnetite superparamagnetic nanoparticles powder properties evidenced, in particular, by the decreased effective system relaxation time.