X-ray study of Kr and Xe adsorbed on the basal plane of nickel chloride

Abstract

X-ray scattering has been used to investigate the structures and phase transitions of Xe and Kr films adsorbed on the basal plane of NiCl2. The x-ray scattering measurements were carried out both as a function of temperature at fixed coverage and as a function of coverage at fixed temperature in the monolayer and bilayer coverage regimes. The results indicate that both the monolayers of Xe and Kr adsorbed on the basal plane of NiCl2 form a 2D solid of the simple triangular structure incommensurate with the substrate and 2D melting is first order in the incommensurate solid of Xe but continuous in that of Kr. With the addition of the second-layer atoms the interparticle distance of the adsorbed atoms reduces and the crystallinity of the incommensurate solid improves.