Growth of Helium Shells inside Spherical Adsorbers

Abstract

The adsorption of helium on spherical cavities is investigated employing finite range density functional theory. It is known that for films outside spherical walls, a growth instability occurs above a critical film thickness. This instability may be overcome by stable capillary condensation inside the gap between an inner sphere and an outer spherical cavity bounded by spherical graphene, metallic sheets and voids in bulk metals. When a C60 fullerene is placed at the center of the spherical well, one can observe the competition between the formation of helium shells on the walls and the attraction of the opposite adsorbing field.