Optical effects in the IR reflection–absorption spectra of thin water-ice films on metal substrates

The effect of film thickness upon the shape of the OH stretching band of thin films of water ice on a gold substrate has been analysed using classical optics. The structure observed in the OH stretching band of films with thicknesses comparable to the wavelength of the IR radiation arises because of a combination of an increased specularly reflected component, an s-polarised component and a relaxation of the metal surface selection rule.