Role of morphology of D_2O ice (20-160 K) in low energy electron stimulated desorption of D~- and O~- anions, and x-ray photon stimulated desorption of D~+ cations

摘要

The low energy electron stimulated desorption yield of D~- anions in pure multilayer D_2O films, and of O~- in submonolayer O_2 covered D_2O films is strongly dependent on the D_2O condensation temperature (20-160 K) on Pt. Likewise the desorption of D~+ cations induced by oxygen 1s excitation to the ground state empty levels of D_2O depends on ice condensation temperature. These observations are connected with the morphology of ice films which are microporous and amorphous at T < 90 K and crystalline at T > 150 K. Moreover both the change of morphology and related adsorption capacity of ice films with condensation temperature are observed in situ with x-ray absorption spectroscopy.