Binary Fluid Phase Separation in Gels: A Neutron Scattering Study

Abstract

Over the past ten years there has been a considerable amount of interest, both theoretical as well as experimental, in the effects of random fields on phase transitions, in particular, the Random Field Ising model (RFIM). Initially, the crucial issue seems to have been the lower critical dimensionality d_c of RFIM¹. In the literature arguments have been given in support of d_c being equal to either 2 or 3 (see references 1, 2 and 3 for recent reviews of RFIM). However, recently it has been realized that, experimentally, RFIM systems get trapped in a nonegyilibrium state which relaxes very slowly, if at all, towards equilibrium⁴. In recent theoretical papers, Villain⁵ and Bruinsma and Aeppli⁶ have come to the conclusion that for d<5, the random field prevents the growth of an ordered state when the system is quenched to low temperatures from the paramagnetic regime.

Supported in part by the University of Delaware research fund grant # LTR 84110