Cerium • Lanthanide Rare Earth
Primary XPS region: Ce3d
Overlapping regions: Ba
MNN
Binding energies of common chemical states:
| Chemical state | Binding energy Ce3d5/2 |
|---|---|
| Ce (IV) oxide | ~882 eV |
| Ce (III) oxide | ~880 eV |
Binding energy ref for Ce(IV) oxide from “Synchrotron XPS data from Ce3+ and Ce4+ oxide reference samples (Oak Ridge National Laboratories, http://www.ornl.gov/sci/schcg/spectroscopy.htm)”
Experimental Information
- Collecting the entire Ce3d region makes data interpretation as straightforward as possible.
Interpretation of XPS spectra
- • Ce3d region has well separated spin-orbit components (Δ=18.6 eV).
- Each spin-orbit component is further split by multiplet splitting.
- ??Don’t peak fit it-just compare and maybe NLLSF??
- The Ce3d spectrum from a pure CeO2 sample, for example, will have six visible components, even though there is only one chemical state.
- Most straightforward method for assigning Ce(III) versus Ce(IV) is to compare complete Ce3d
envelope with reference data (see below).
- Ce(III) and Ce(IV) spectra have different multiplet splitting.
- Ce(IV) has peak at 917eV which is absent in Ce(III) spectrum.
General comments
- Common oxidation states : Ce (III) and Ce (IV)
Resources
- [1] Beche et al., Sur f . In t er f ace An al. 2008; 40: 264–267
About This Element
Symbol: Ce
Date of Discovery: 1803
Name Origin: Ceres
Appearance: gray
Discoverer: W. von Hisinger
Obtained From: monazite, orthite
Melting Point: 1068 K
Boiling Point: 3633 K
Density[kg/m3]: 6689
Molar Volume: 20.69 × 10-6 m3/mol
Protons/Electrons: 58
Neutrons: 82
Shell Structure: 2,8,18,19,9,2
Electron Configuration: [Xe]4f15d16s2
Oxidation State: 3,4
Crystal Structure: hexagonal
Cerium, named after the dwarf planet Ceres, is a soft, malleable, and ductile metal. It is likely to ignite when scratched with a knife, and can ignite spontaneously in air at 65 to 80 °C. Its flames are toxic. Water should not be used to put out cerium fires, as its reaction with water produces hydrogen gas. Although known as a rare earth metal, cerium is not rare at all. Available in large quantities, cerium is even more abundant than lead. This element is widely used in making aluminum and heat-resistant alloys.
