Borodin A, Höfft O, Kempter V
Technische Universität Clausthal, Institut für Physik und Physikalische Technologien, Leibnizstr. 4, D-38678 Clausthal-Zellerfeld, Germany.
J Phys Chem B. 2005 Aug 25;109(33):16017-23. doi: 10.1021/jp0521306.
The interaction of CsF with multilayered water has been investigated with metastable impact electron spectroscopy (MIES) and ultraviolet photoelectron spectroscopy with HeI (UPS(HeI)). We have studied the emission 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 annealed between 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) layers deposited on thin H2O (CsF) films (stoichiometry CsF.1.5H2O) gradually transform into a mixed layer containing F, Cs, and H2O species. When annealing, H2O molecules can be detected up to 200 K from the mixed F-Cs-H2O layer (while for pure H2O desorption is essentially complete at 165 K); a water network is 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 takes place, even for the species closest to the surface, as long as the stoichiometry remains CsF.(H2O)n with n > 3.
利用亚稳态碰撞电子能谱（MIES）和HeI紫外光电子能谱（UPS(HeI)）研究了CsF与多层水的相互作用。我们研究了H₂O的1b₁、3a₁和1b₂态、Cs的5p态以及F的2p态电离产生的发射。我们制备了CsF - H₂O界面，即在多层水薄膜上的CsF层以及反之亦然；它们在80至约280 K之间进行退火处理。在约100 K以下，可以在H₂O上沉积封闭的CsF层，反之亦然；未观察到H₂O和CsF这两种成分的相互渗透。在110 K以上，沉积在薄H₂O（CsF）薄膜上的CsF（H₂O）层（化学计量比为CsF·1.5H₂O）逐渐转变为包含F、Cs和H₂O物种的混合层。退火时，从混合的F - Cs - H₂O层中在200 K时仍可检测到H₂O分子（而对于纯H₂O，在165 K时脱附基本完成）；在这些条件下未形成水网络，并且所有H₂O分子都参与与Cs⁺和F⁻离子的键合。当在120 K下将CsF沉积在足够厚的水多层膜上时，只要化学计量比保持为CsF·(H₂O)ₙ且n > 3，F和Cs的完全溶剂化就会发生，即使对于最靠近表面的物种也是如此。
