  The dynamical responses of random field Ising model at zero temperature,
driven by standing magnetic field wave, is studied by Monte Carlo simulation in
two dimensions. The three different kinds of distribution of quenched random
field are used here, uniform, bimodal and Gaussian. In all cases, three
distinct dynamical phases were observed, namely, the pinned, structured and
random. In the pinned phase no spin flip is observed. In the structured phase
standing spin wave modes are observed. The random phase is shown no regular
pattern. For a fixed value of the amplitude of the standing magnetic field
wave, in the region of small quenched field, the system remains in a pinned
phase. In the intermediate range of values of random field, a standing spin
wave mode (structured phase) is observed. The regular pattern of this spin wave
mode disappears for higher values of random field yielding a random phase. The
comprehensive phase baundaries are drawn in all three cases. The boundary of
pinned phase are analytically calculated for uniform and bimodal types of
quenched random fields.
