The vibrational spectra of water cluster molecules on Pt(111) surface at 20 K

The adsorption of D2O on Pt(111) at 20 K has been investigated by infrared reflection absorption spectroscopy (IRAS). Water was found to form as a dimer at low coverages and it grew a tetramer molecule at high coverages. The structures of the cluster water molecules on the surface were derived from the intensities and the frequencies of symmetric and asymmetric ν OD stretching absorptions. The annealing at higher temperatures than 130 K was needed to form an ice bilayer island structure.