Adsorption of krypton on alkali halide crystals. Part 1.—Theory

Abstract

The adsorption of krypton on alkali halide crystals with the NaCl-type structure has been studied theoretically in order to analyze detailed experimental data given in a succeeding paper. Emphasis was placed on the mutual interaction between adsorbates, perturbed by the solid adsorbent (the third body effect). Changes of lateral vibrational state of the adsorbed krypton with coverage were taken into consideration in deriving an adsorption isotherm.

An analysis is given of the third body effect in the localized adsorption model, and an equation derived which correlates the third body effect with the surface electric field. Using this equation, one can estimate the order of magnitude of the field strength, and, in favourable cases, verify the existence of the distortion of the surface lattice postulated by Benson and coworkers.