| AVS 59th Annual International Symposium and Exhibition | |
| Surface Science | Wednesday Sessions |
| Session SS+OX-WeM |
| Session: | Synthesis and Characterization of Oxides |
| Presenter: | P.S. Bagus, University of North Texas |
| Authors: | P.S. Bagus, University of North Texas E.S. Ilton, Pacific Northwest National Laboratory C.J. Nelin, Consultant |
| Correspondent: | Click to Email |
The satellites in X-Ray photoemission spectroscopy, XPS, especially for ionic compounds, are an important part of the spectra [1, 2] and may provide information about the electronic structure. For uranium oxides, they allow the oxidation state of the U cations to be determined. [2] It would be useful to establish and to understand how the satellite intensity may be related to the extent of covalent bonding in an oxide or other ionic material. It is often believed that the intensity lost from the main XPS peaks to satellites is directly related to the covalent bonding, with greater covalent bonding leading to greater losses to satellites. We show that this relationship is not rigorously correct. A more correct relationship is between satellite intensity and the difference of the degrees of covalency in the initial, unionized, state and the final, core-hole states with larger differences leading to larger losses to satellites.. Furthermore, the final state covalency is less sensitive to the environment than is the initial state covalency since the bonding in the final state is more appropriate to that for an equivalent, Z+1, impurity atom representing the core-ionized atom. [3] We investigate the extent to which the effects of covalency can be tuned by comparing the Ni 2p XPS between NiO and Ni impurities in MgO.
1. P. S. Bagus, et al., Chem. Phys. Lett. 487, 237 (2010).
2. E. S. Ilton and P. S. Bagus, Surf. Interface Anal. 43, 1549 (2011).
3. W. L. Jolly and D. N. Hendrickson, J. Am. Chem. Soc. 92, 1863 (1970).