Nonequilibrium morphology of liquid inclusions migrating in solids

Abstract

The nonequilibrium shape of a liquid droplet migrating in a thermal gradient in a solid depends on both anisotropic surface energy and its anisotropic interface kinetics. In contrast, in equilibrium, the droplet shape is simply a surface of minimal total interfacial energy. From the surface energy and interface kinetic anisotropy the shape of brine droplets migrating in KCl is calculated for different migrating rates, droplet volumes, and orientations of the thermal gradient. As the migration rate increases, the droplet flattens by having its dissolving facets grow and the solidifying facets shrink in size. A gradient in the curvature of the interface is generated by the nonequilibrium composition gradient in the liquid. The shape of molten‐metal wires used to dope semiconductors by thermomigration is also discussed.