Growth kinetics for a system with a conserved order parameter: Off-critical quenches

摘要

The theory of growth kinetics developed previously [G. F. Mazenko, Phys. Rev. E 50, 3485 (1994)] is extended to the asymmetric case of off-critical quenches for systems with a conserved scalar order parameter. In this instance, the new parameter M, the average global value of the order parameter, enters the theory. For M=0 one has critical quenches, while for sufficiently large M one approaches the coexistence curve. For all M, the theory supports a scaling solution for the order parameter correlation function with the Lifshitz-Slyozov-Wagner growth law L~t1/3. The theoretically determined scaling function depends only on the spatial dimensionality d and the parameter M, and is determined explicitly here in two and three dimensions. Near the coexistence curve oscillations in the scaling function are suppressed. The structure factor displays Porod's law Q-(d+1) behavior at large scaled wave number Q, and Q4 behavior at small wave number, for all M. The peak in the structure factor widens as M increases and develops a significant tail for quenches near the coexistence curve. This is in qualitative agreement with simulations.