IMPURITY EFFECTS IN THERMAL REGELATION

Abstract:

When a particle is placed in a material with a lower bulk melting temperature, intermolecular forces can
lead to the existence of a premelted liquid film of the lower melting temperature material. Despite the
system being below the melting temperatures of both solids, the liquid film is a consequence of
thermodynamic equilibrium, controlled by intermolecular, ionic and other interactions. An imposed
temperature gradient drives the translation of the particle by a process of melting and refreezing known as
thermal regelation. We calculate the rate of regelation of spherical particles surrounded by premelted
films that contain ionic impurities. The impurities enhance the rate of motion thereby influencing the
dynamics of single particles and distributions of particles, which we describe in addition to the
consequences in natural and technological settings.