The kinetics of the ordering and coarsening of B2-ordered domains was studied using atomistic kinetic Monte Carlo simulations. Special emphasis was put on the effect of annealing temperature, alloy composition, and atom dynamics on the coarsening behavior. When atomic diffusion proceeds by vacancy jumps to nearest-neighbor sites, a transient slow coarsening regime was observed at temperatures below half the order-disorder transition temperature Tc. It results in apparent coarsening exponents that decrease with decreasing the annealing temperature. Values as low as 0.14 were measured at 0.25Tc. Slow transients take place in both stoichiometric and non-stoichiometric alloys. These regimes were correlated with the transient creation of excess antisites during domain disappearance. Since antiphase boundary mobility decreased with increasing antisite concentration, this transient excess results in the slow coarsening observed in simulations.

Slow Coarsening of B2-Ordered Domains at Low Temperatures: a Kinetic Monte Carlo Study. D.Le Floc'h, P.Bellon, M.Athènes: Physical Review B, 2000, 62[5], 3142-52