Condensation bidimensionnelle de l'oxygène sur les halogénures lamellaires

Sets of adsorption isotherms of oxygen on the cleavage face of a number of lamellar halides have been determined. The isotherms show three vertical steps, corresponding to the formation of three successive monomolecular layers during two-dimensional (2D) condensation. From the values taken by the entropy of the various layers and by their critical temperatures of 2D condensation, it is inferred that first layers have a cristalline structure influenced by the surface while the following ones are liquid-like.