Abstract
We present computer simulations on the super-paramagnetic blocking phenomena in wide band-gap dilute magnetic semiconductors (DMSs) in particular (Ga, Mn)N. It is shown that due to the formation of magnetic nano-clusters of magnetic impurities under the spinodal decomposition, super-paramagnetic blocking temperature (TB) of the DMS is enhanced and hysteretic magnetic response can be observed at finite temperature even if Curie temperature of the whole system is nearly zero. TB higher than room temperature can be expected and the blocking phenomena explains reported ferromagnetic behaviour of wide band-gap DMS at high temperature.