COMPUTER-SIMULATION STUDY OF PHASE-SEPARATION IN A BINARY MIXTURE WITH A GLASS-FORMING COMPONENT

We present a computer simulation study of spinodal decomposition with one of the two phases freezing in a glassy state during phase separati on. As a model we used the Cahn-Hilliard equation with a concentration -dependent mobility coefficient which decreases rapidly with increasin g concentration of the glass-forming component. We solved the Cahn-Hil liard equation numerically for two dimensions. The domain growth depen ds crucially on the volume fraction of the glassy phase. For high volu me fractions, when the glassy phase forms a percolating matrix, a nove l coarsening mechanism is discovered, which arises from the migration and coalescence of liquid droplets within the glassy matrix. Various q uantities characterizing the time-dependent domain pattern, like dropl et size distribution, one- and two-point distribution function and str ucture factor of the concentration field, are computed. We checked the validity of the dynamic scaling hypothesis.