Spectral Structure of Critical Opalescence: Binary Mixture.

Abstract
The linearized hydrodynamic equations of irreversible thermodynamics are used to obtain the time dependence of the kth Fourier component of a concentration fluctuation in the one-phase region of a binary mixture. The frequency of the light scattered by concentration fluctuations near the critical mixing point is found to be broadened into a Lorentzian distribution with a half-width proportional to the mass diffusion coefficient, D. The possibility of detecting space dispersion in D is discussed.