Scaling Function for the Structure Factor in First-Order Phase Transitions

A simple, phenomenological theory is presented for the scaling function of a phase-separating binary system. The model describes a gas of spherical droplets of the minority phase, surrounded by depletion zones, and involves a simple approximation for the two-point distribution function. Reasonable agreement is found with the structure factors for the kinetic Ising model, binary alloys, and binary liquids.