Orbitals and Energies #
Note – these are listed in BINDING ENERGY
Eu 3d ≈ 1130 eV
Eu 4s ≈ 360 eV
Eu 4p ≈ 260 eV
Eu 4d ≈ 135 eV
Eu 5s ≈ 32 eV
Eu 5p ≈ 22 eV
Common Overlaps for Eu 3d #
Ga 2p – La 3p – Ba 3p – Xe 3s – Fr 4s – Sc LMM (Al Ka X-rays) – Pd MNN (Al Ka X-rays) – Ag MNN (Al Ka X-rays)
Theory and Background #
Creation of a core-hole in Eu compounds, this lowers the energy of the unoccupied 4f-subshells due to Coulombic interactions between the core-hole and the electronic system. This allows a conduction electron to occupy one of these 4f orbitals, resulting in an apparent change in valence state, and appearance of an additional satellite peak.[1]
Experimental Advice #
Record both Eu 3d and Eu 4d if possible, to give the best chance of speciating the Eu chemistry. Eu 3d 3/2 region does not need to be recorded given the high doublet separation.
Data Analysis Guidance #
Eu 3d and Eu 4d both exhibit satellites from shake-down effects that can help speciate the Eu chemistry, since both position and intensity are dependant on chemical environment.
References #
- Mercier, Florian, et al. “XPS study of Eu (III) coordination compounds: Core levels binding energies in solid mixed-oxo-compounds EumXxOy.” Journal of electron spectroscopy and related phenomena 150.1 (2006): 21-26. Read it online here.
