Mass density and refractive index of quench-condensed argon-krypton films

Abstract

The refractive index and the mass density of ArKr films condensed on a silicon substrate at liquid helium temperature are determined by ellipsometric measurements at a wavelength Λ= 632.8 nm. The densities of the crystalline ArKr films are typically 3.5% less than the corresponding bulk values. This deviation is much less than in the case of recently investigated ArXe mixtures. No annealing effect has been observed except when the Ar atoms sublime from the layer. Like in the case of ArXe mixtures, ArKr films with a high initial Ar concentration remain in a highly porous sponge structure after the Ar atoms have left the layer.