AVS 52nd International Symposium
    Surface Science Thursday Sessions
       Session SS1-ThM

Paper SS1-ThM8
Ionization of Water-Ice Layers on Platinum: Effect of Carbon Monoxide

Thursday, November 3, 2005, 10:40 am, Room 200

Session: Water-Surface Interactions
Presenter: R.A. Manghani, University of Washington
Authors: R.A. Manghani, University of Washington
V.K. Medvedev, University of Washington
E.M. Stuve, University of Washington
Correspondent: Click to Email
Field ionization of water on a platinum field emission tip was studied in the presence of carbon monoxide (CO) as co-adsorbate. Water adlayers 5 - 400 Å thick were grown under field-free conditions at 108 K by exposure of cryogenically cooled emitter tip to water vapor in ultrahigh vacuum. Onset of field ionization of water layers was probed by ramped field desorption (RFD) on platinum and CO saturated platinum emission tip. Onset field for water ionization on CO saturated platinum was found to be lower than that for water adsorbed on bare platinum. Facilitation of ionization by saturated CO on platinum was attributed to enhancement in the local field. The effect decreased with increasing water thickness, but existed for thick water layers. Effect of CO on water ionization is discussed and a model is presented.