Possible structures for alkali ions on the surface of alkali halides

Abstract
During the process of defect formation in alkali halides irradiated with 500 eV electrons, halogen atoms are ejected from the surface. In contrast the metal ions remain on the surface until they are thermally evaporated. Two extreme forms of this alkali layer are considered, namely, isolated alkali ions or a monolayer of an FCC alkali metal. A simple electrostatic calculation favours the isolated ion model.