Nucleation of freezing by charged particles. I. Thermodynamics

We determine the properties of the solid region which surrounds an ion embedded in a compressible atomic liquid. This solid acts as a nucleation center for freezing of the liquid when it is compressed above the melting pressure. Specifically, we evaluate the solid radius, the activation free energy barrier of the ion complex with respect to freezing of the bulk liquid, and the critical overpressure δp_c at which the finite radius solid becomes absolutely unstable. We present an alternative approach to the quantity δp_c in terms of the spherical solid's growth in response to an external perturbation.