Cerium • Lanthanide Rare Earth

Primary XPS region: Ce3d
Overlapping regions: Ba MNN
Binding energies of common chemical states:

Chemical stateBinding 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)


  • [1] Beche et al., Sur f . In t er f ace An al. 2008; 40: 264–267

crystal structureAbout 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.

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