Fa. Pinheiro et al., Vanishing of energy transport velocity and diffusion constant of electromagnetic waves in disordered magnetic media, PHYS REV L, 85(26), 2000, pp. 5563-5566
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.