Abstract
The adsorption of HBr on LiF(001) single crystal surfaces was studied as a function of coverage by means of Fourier-transform infrared (FTIR) Spectroscopy at temperatures ⩽83 K. Three different spectral features could be distinguished. The absorption of the first layer was found to be redshifted by ~300 cm −1 with respect to gas-phase molecules, its fwhm being 265±25 cm −1. The absorption intensity was more than one order-of-magnitude enhanced over that of gas-phase molecules. From these results we conclude that first-layer HBr is hydrogen-bonded to F − ions of the surface, the angle between the molecular axis and the surface being 21±5° as determined from experiments employing polarized infrared. The second layer (and at low enough temperatures also higher layers) were ~100 cm −1 redshifted with respect to the gas-phase absorption, fwhm=75±10 cm −1. With increasing coverage the doublet absorption characteristic of solid orthorhombic HBr could be observed.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
