Non-universality of phase separation in two-dimensional critical binary-fluid mixtures

¹ Instituto de Física, Universidade Federal do Rio Grande do Sul Caixa Postal 15051, 91501-970 Porto Alegre, RS, Brasil
² Facultad de Física, P. Universidad Católica de Chile - Casilla 306, Santiago 22, Chile

Received: 8 November 1996
Accepted: 22 June 1997

Abstract

The domain growth in the late-time regime of phase-separating two-dimensional critical fluid mixtures is investigated with molecular-dynamics simulations. Growth exponents are found to depend not only on temperature, as was previously shown, but also on the particular pair interaction potential. We study this dependence for two different molecular pair potentials with reduced strength among unequal particles and discuss possible mechanisms for the coarsening process as a function of temperature. At the low-temperature quenching regime the phase separation shows percolating patterns not previously reported, where a sequential aggregation of clusters gives rise to a possible multi-scaling behaviour.