Determining fluid-crystal phase boundaries for a binary hard-sphere mixture using direct-coexistence simulations

Area of Science:

• Materials Science
• Chemical Engineering
• Computational Chemistry

Background:

• Direct-coexistence simulations for fluid-crystal phase boundaries are often complicated by crystal strain.
• A recent direct-coexistence method simplifies identifying equilibrium strain-free fluid-crystal coexistence in monodisperse systems.

Purpose of the Study:

• To extend the strain-free direct-coexistence method to binary mixtures forming stoichiometric binary crystals.
• To accurately and efficiently determine fluid-crystal phase boundaries in these systems.
• To investigate the influence of crystal plane selection on phase boundary accuracy.

Main Methods:

• Adaptation of a direct-coexistence approach for binary mixtures.
• Simulation of stoichiometric binary crystals in contact with their fluid phase.
• Analysis of the impact of different crystal planes on phase boundary determination.

Main Results:

• The direct-coexistence method was successfully extended to binary mixtures forming stoichiometric binary crystals.
• Accurate and efficient determination of fluid-crystal phase boundaries was achieved.
• The choice of crystal plane was shown to affect the accuracy of phase boundary determination.

Conclusions:

• The extended direct-coexistence method provides a robust and practical tool for determining fluid-crystal phase boundaries in binary mixtures.
• The method is easy to implement and does not require prior knowledge of the binary fluid's equation of state.
• This work establishes a reliable approach for understanding phase behavior in complex fluid systems.