Relaxation-to-creep transition of domain-wall motion in two- dimensional   random-field Ising model with ac driving field
  With Monte Carlo simulations, we investigate the relaxation dynamics with a domain wall for magnetic systems at the critical temperature. The dynamic scaling behavior is carefully analyzed, and a dynamic roughening process is observed. For comparison, similar analysis is applied to the relaxation dynamics with a free or disordered surface 
N.J. Zhou, B. Zheng and D.P. Landau
cond-mat.stat-mech