We study the phase-separation dynamics of a two-dimensional Ising model where A and B particles can only exchange position with a vacancy. In a wide range of temperatures the kinetics is dominated, during a long preasymptotic regime, by diffusion processes of particles along domain interfaces. The dynamical exponent z associated to this mechanism differs from the one usually expected for Kawasaki dynamics and is shown to assume different values depending on temperature and relative $\mathrm{AB}$ concentration. At low temperatures, in particular, domains grow as $t^{1/2},$ for equal $\mathrm{AB}$ volume fractions.

• Received 26 September 2000

DOI:https://doi.org/10.1103/PhysRevB.63.060102