Deuterated water adsorption on epitaxially grown FeO(111), Fe 3 O 4 (111) and Fe 2 O 3 (biphase) films was investigated in the range 110-320 K by infrared reflection-absorption spectroscopy (IRAS) and temperature programmed desorption (TPD) spectroscopy. At 110 K, a first water layer forms on Fe 3 O 4 (111) and Fe 2 O 3 (biphase) before the second and higher layers develop. The first half layer on Fe 3 O 4 adsorbs dissociatively. The second half layer develops features characteristic for hydrogen bonding and the formation of dimers is concluded. Also on Fe 2 O 3 (biphase), initial water adsorption is dissociative. A strongly bound minority species is observed. Heating to 169 K causes formation of ice clusters. On FeO(111) adsorption is molecular and weak. On all studied surfaces, thick ice layers grown at 110 K are amorphous. On Fe 3 O 4 (111) they transform at 170 K into hexagonal ice (Ice H ) while up to 10 L on FeO(111) remain amorphous. The mechanisms for adsorption and ice formation correlate with structure and termination of the different oxide surfaces.

A compact, versatile, and simple rf plasma source with capacitive coupling compatible to ultrahigh vacuum (UHV) requirements was designed and built to allow sequences of sample surface modification in plasma and surface preparation and analysis in vacuum without breaking the vacuum. The plasma source was operated at working pressures of less than 1 to a few millibars. Sample transfer to UHV was performed at pressures around 10−9mbar. For easy integration into an existing UHV setup, the sample recipient and transfer system were made to accept standard commercial sample holders. Preliminary experiments were performed by exposing monolayers of colloidal CoPt3 nanoparticles to oxygen and hydrogen plasmas. The structural and chemical effects of the plasma treatments were analyzed with scanning electron microscopy and x-ray photoelectron spectroscopy.