Surface structural dependence of cesium adsorption on the {alpha}-Al{sub 2}O{sub 3}(0001) surface
- Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-5800 (United States)
- AEA Technology, TOPAZ International Program, 901 Univeristy Blvd. SE, Albuquerque, New Mexico 87106-4439 (United States)
The structural dependence of Cs adsorption on the {alpha}-Al{sub 2}O{sub 3}(0001) surface has been studied using a combination of surface analytical techniques. The unreconstructed or (1{times}1) surface shows a high initial Cs adsorption probability of 0.9 based on reflection mass spectrometry (RMS). This value decreases rapidly after a critical Cs coverage of 1.5{times}10{sup 14} atoms/cm{sup 2} is reached. Thermally-induced surface reconstruction to form an O deficient surface results in a decrease in the critical coverage, probability and capacity for Cs adsorption. Low energy electron diffraction (LEED) demonstrates that a predominantly (3{radical}3{times}{radical}3)R30{degree} surface yields an initial adsorption probability of 0.5 while a predominantly ({radical}31{times}{radical}31)R{plus_minus}9{degree} yields a value of 0.3. Thermal desorption mass spectrometry (TDMS) shows that surface reconstruction suppresses the high binding energy states of Cs, consistent with the observed changes in adsorption probability. X-ray photoelectron spectroscopy (XPS) provides no direct evidence for formal oxidative/reductive chemistry taking place at the interface. We interpret the facile adsorption and strong binding of Cs on sapphire to result from Cs interacting with coordinatively unsaturated O. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}
- Research Organization:
- Sandia National Laboratory
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 102085
- Report Number(s):
- CONF-950110--
- Journal Information:
- AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 324; ISSN 0094-243X; ISSN APCPCS
- Country of Publication:
- United States
- Language:
- English
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