The random field critical concentration in dilute antiferromagnets
  Monte Carlo techniques are used to investigate the equilibrium threshold concentration, xe, in the dilute anisotropic antiferromagnet Fe(x)Zn(1-x)F2 in an applied magnetic field, considered to be an ideal random-field Ising model system. Above xe equilibrium behavior is observed whereas below xe metastability and domain formation dominate. Monte Carlo results agree very well with experimental data obtained using this system. 
W. C. Barber and D. P. Belanger