Neutron scattering experiments and simulations near the magnetic   percolation threshold of Fe_x Zn_{1-x} F_2
  The low temperature excitations in the anisotropic antiferromagnetic Fe_{1-x} Zn_x F_2 for x=0.25 and 0.31, at and just above the magnetic percolation threshold concentration x_p=0.25, were measured using inelastic neutron scattering. The excitations were simulated for x=0.31 using a localized, classical excitation model, which accounts well for the energies and relative intensities of the excitations observed in the scattering experiments. 
G. Alvarez, N. Aso, D. P. Belanger, A. M. Durand, V. Martin-Mayor, K.   Motoya, Y. Muro
cond-mat.str-el cond-mat.dis-nn