Role of morphology of D2O ice (20-160 K) in low energy electron stimulateddesorption of D- and O- anions, and x-ray photon stimulated desorption of D+ cations

The low energy electron stimulated desorption yield of D- anions in pure mu ltilayer D2O films, and of O- in submonolayer O-2 covered D2O films is stro ngly dependent on the D2O condensation temperature (20-160 K) on Pt. Likewi se the desorption of D+ cations induced by oxygen Is excitation to the grou nd state empty levels of D2O depends on ice condensation temperature. These observations are connected with the morphology of ice films which are micr oporous and amorphous at T < 90 K and crystalline at T > 150 K. Moreover bo th the change of morphology and related adsorption capacity of ice films wi th condensation temperature are observed in situ with x-ray absorption spec troscopy. (Int J Mass Spectrom 205 (2001) 325-330) (C) 2001 Elsevier Scienc e B.V.