title: Initial growth of the water layer on (1 x 1)-oxygen-covered Ru(0001) in comparison with that on bare Ru(0001).
abstract: The initial growth of a water (D2O) layer on (1 x 1)-oxygen-covered Ru(0001) has been studied in comparison with that on bare Ru(0001) by means of temperature-programmed desorption (TPD) and infrared reflection absorption spectroscopy (IRAS). Although water molecules adsorbed on both bare and (1 x 1)-oxygen-covered Ru(0001) commonly tend to form hydrogen bonds with each other when mobility occurs upon heating, the TPD and IRAS measurements for the two surfaces exhibit distinct differences. On (1 x 1)-oxygen-covered Ru(0001), most of the D2O molecules were desorbed with a peak at 160 K, even at submonolayer coverage, as condensed water desorption. The vibration spectra of adsorbed D2O also showed broad peaks such as a condensed water phase, from the beginning of low coverage. For submonolayer coverage, in addition, we found a characteristic O-D stretching mode at around 2650 cm(-1), which is never clearly observed for D2O on bare Ru(0001). Thus, we propose a distinctive water adsorption structure on (1 x 1)-oxygen-covered Ru(0001) and discuss its influence on water layer growth in comparison with the case of D2O on bare Ru(0001).
authors.affiliation: RIKEN (The Institute of Physical and Chemical Research), Wako 351-0198, Japan.
authors.forename: Michel Malick
authors.initials: MM
authors.lastname: Thiam
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kondo
authors.forename: Noriko
authors.initials: N
authors.lastname: Horimoto
authors.forename: Hiroyuki S
authors.initials: HS
authors.lastname: Kato
authors.forename: Maki
authors.initials: M
authors.lastname: Kawai