New Mechanism for the Desorption of Excited Atoms by Photon Bombardment of AlkaliHalide Crystals

摘要

We report measurements of photon-stimulated desorption of excited atoms from LiFand NaCl crystal surfaces. Based on these measurements, we propose a new model of photon-initiated, defect-mediated desorption involving exoergic surface reactions between alkali dimers and halogens. This model consists of two steps: (a) reactants are formed at the surface, directly or by the migration to the surface of holes and defects created in the near surface bulk, due to uv photon bombardment, and (b) excited alkali atoms are emitted following a reaction between the alkali and halogen surface species. jg p2.