NEW APPROACH TO THE THEORY OF SPINODAL DECOMPOSITION

A new approach to the study of spinodal decomposition for a scalar fie ld is proposed. The approach is based on treating this process as a re laxation of the one-time correlation function G(q,t)=integral dr[phi(0 ,t)phi(r,t)]exp(iq.r), which plays the role of an independent dynamica l object (a unique two-point order parameter). The dynamical equation for G(q,t) (the Langevin equation in correlation-function space) is so lved exactly in the one-loop approximation, which is the zeroth approx imation in the approach proposed. This makes it possible to trace the asymptotic behavior of G(q,t) at long and intermediate times t (from t he moment of onset of the spinodal decomposition). The values obtained for the power-law growth exponents for the height and position of the peak in G(q,t) at the intermediate stage is in satisfactory agreement with the data obtained by a number of authors through numerical simul ation of the corresponding stochastic equations describing the relaxat ion of the local order parameter. (C) 1997 American lnstitute of Physi cs.