Figure 6.

Finite-size scaling analysis of the phase transition between the lo/ld coexistence region and the fluid phase. (a) The composition fluctuation χ versus J for various system sizes L and γ = 1. The pronounced peak, at J = J_L, and the increase of the peak height χ_L with L, indicates that a phase transition occurs. (b) The scaling of the maximum composition fluctuation lnχ_L with lnL for γ = 1. The linear increase indicates a power-law χ_L ∝ L^r, with r ∼ 2.0 obtained by fitting. This shows that the transition for γ = 1 is first-order. (c) The exponent r versus γ. For large γ, the transition is first-order (r = 2), whereas lower values of γ reveal a continuous transition approaching r = 7/4 of the two-dimensional Ising model. (d) J_L versus L⁻² for γ = 1. (Dashed line) Linear fit, whose intercept yields J_∞ of the thermodynamic limit. To see this figure in color, go online.