PHASE-DIAGRAM OF A MODEL ANTICLUSTERING BINARY MIXTURE IN 2 DIMENSIONS - A SEMI-GRAND-CANONICAL MONTE-CARLO STUDY

The temperature-density phase diagram of a model binary mixture in two -dimensions is investigated using a semi-grand-canonical Monte Carlo s imulation scheme which allows for exchange between the two species whi le keeping the total number of atoms fixed. The gas-liquid and the gas -solid regions of the phase diagram are mapped out using the efficient block analysis method incorporating finite-size scaling of the variou s coexisting densities. An ordered square lattice structure is seen to be stable at low temperatures. Interesting short-range ordering pheno mena resulting in a ''disorder line'' in the fluid phase are also anal yzed and compared with results from liquid-state integral equation the ories.