Phase behavior of binary hard-sphere mixtures: Free volume theory including reservoir hard-core interactions

Comprehensive calculations were performed to predict the phase behavior of large spherical colloids mixed with small that act as a depletant. To this end, free volume theory (FVT) Lekkerkerker et al. [Europhys. Lett. 20, 559 (1992)] is used basis and extended explicitly include hard-sphere character colloidal depletants into expression for fraction. Taking excluded account in both system reservoir provides relation between depletant concentration accurately matches computer simulation results Dijkstra [Phys. Rev. E 59, 5744 (1999)]. Moreover, diagrams highly asymmetric mixtures size ratios q ? 0.2 obtained by using new approach corroborate significantly better than earlier FVT applications binary mixtures. The diagram mixture ratio = 0.4, where interstitial solid solution formed at high densities, investigated numerical approach. At ratio, qualitatively different from previous approaches penetrable but again compares well predictions.