Vanishing of energy transport velocity and diffusion constant of electromagnetic waves in disordered magnetic media

The energy transport velocity nu (E) and the diffusion constant D of electr omagnetic waves in the presence of randomly distributed ferromagnetic scatt erers are studied. nu (E) presents a strong dependence on the relative magn etic permeability mu. and, unlike the nonmagnetic case, exhibits sharp drop s in the small-particle limit and never coincides with the phase velocity n u (p). Both nu (E) and D exhibit an oscillatory dependence on mu and vanish for certain values of mu. Since mu. of ferromagnetic scatterers strongly d epends on the temperature and applied magnetic field, we suggest that these facts can be explored in technological applications.