AVS 52nd International Symposium
    Surface Science Monday Sessions
       Session SS-MoP

Paper SS-MoP14
Adsorption of Sulfur Dioxide on Zircaloy-4

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Surface Science Poster Session
Presenter: N. Stojilovic, The University of Akron
Authors: N. Stojilovic, The University of Akron
R.D. Ramsier, The University of Akron
Correspondent: Click to Email
The adsorption of sulfur dioxide on Zircaloy-4 surfaces is investigated using Auger electron spectroscopy. We find that both surface oxidation and saturation with sulfur and oxygen occur at low coverages at 300 K. Heating above 800 K results in oxygen dissolution into the bulk whereas sulfur stays in the near surface region. We examine effects of this residual sulfur on subsequent sulfur dioxide and oxygen adsorption. In both cases the adsorbates oxidize the sulfur-contaminated surface. Sulfur dioxide exposures at 300, 600 and 900 K all result in similar amounts of surface sulfur, indicating similar sticking coefficients in this temperature range. However, 900 K adsorption does not result in a shift of the Zr(MNN) feature that would signify surface oxidation. Thus this system can either adsorb or absorb oxygen from sulfur dioxide depending on the temperature, and the sulfur remains trapped near the surface without poisoning it with respect to subsequent oxidation.