Impurity effects on domain-growth kinetics. II. Potts model

The development of order for the Q-state Potts model for 2<Q≤48 in the presence of static, random impurities is studied following a quench from high temperature (T≫$T_c$) to very low temperatures. We find that the domain growth becomes pinned for quenches to T=0 and the average pinned domain area $A_f$ varies inversely with the concentration c of impurities. This value of the proportionality factor between $A_f$ and $c^{\mathrm{-}1}$ can be understood in terms of a simple topological analysis for large Q.