Resumen de Magnetic susceptibility of ferrofluids determined from diffusion coefficient of a tracer
R. Peredo Ortíz, M. Hernández-Contreras
Linear response methods allow studying magnetic susceptibility relaxation in isotropic colloidal magnetic fluids. We show a relationship between the susceptibility of macroscopic magnetization at thermal equilibrium and the diffusion constant of a tracer particle. The comparison of the predicted frequency-dependent susceptibility with computer simulations shows their agreement. Besides, at a low concentration of particles, it has the expected Debye behavior. However, the initial susceptibility yields only the qualitative trends of the existing experiments at a low volume fraction of particles and its temperature dependence.
