Kinetics of precursor-mediated ordering of two-dimensional domains

Monte Carlo simulations have been carried out to study the kinetics of precursor-mediated ordering of a lattice gas with nearest- and next-nearest-neighbor repulsive interactions. We find that the growth exponent x is affected strongly by the rate at which a precursor is deexcited into a chemisorbed state. If this rate is high, x is close to the value obtained for conservation of density. If this rate is low, x is close to the value for nonconserved density even though the total number of particles is actually conserved. We conclude that the length of precursor ``hops'' influences the growth exponent.