| Abstract
| - The interaction of CsF with multilayered water has been investigated with metastable impact electronspectroscopy (MIES) and ultraviolet photoelectron spectroscopy with HeI (UPS(HeI)). We have studied theemission from the ionization of H2O states 1b1, 3a1, and 1b2; of Cs5p and of F2p. We have prepared CsF−H2O interfaces, namely, CsF layers on thin films of multilayered water and vice versa; they were annealedbetween 80 and about 280 K. Up to about 100 K, a closed CsF layer can be deposited on H2O and vice versa;no interpenetration of the two components H2O and CsF could be observed. Above 110 K, CsF (H2O) layersdeposited on thin H2O (CsF) films (stoichiometry CsF·1.5H2O) gradually transform into a mixed layercontaining F, Cs, and H2O species. When annealing, H2O molecules can be detected up to 200 K from themixed F−Cs−H2O layer (while for pure H2O desorption is essentially complete at 165 K); a water networkis not formed under these conditions, and all H2O molecules are involved in bonding with Cs+ and F- ions.When CsF is deposited at 120 K on sufficiently thick water multilayers, full solvation of both F and Cs takesplace, even for the species closest to the surface, as long as the stoichiometry remains CsF·(H2O)n withn> 3.
|
