CONCENTRATION FLUCTUATIONS OF A BINARY-LIQUID MIXTURE IN A MACROPOROUS GLASS

We performed static and dynamic light scattering measurements for the binary liquid mixture, carbon disulfide-nitromethane, imbedded in a 1000-angstrom porous glass. The system exhibits strong spatial but weak temporal fluctuations, giving rise to interesting nonergodic behavior. A reasonably sharp transition was detected at a temperature approximately 1 K below the bulk T(C) with the system showing critical slowing-down on both sides of the transition. Despite the large pore size (in comparison with the correlation length), the intensity-intensity autocorrelation function is nonexponential with a characteristic relaxation time that does not diverge even at low temperatures, T << T(C). Our observations cannot be explained by the random-field model.