Abstract
We have utilized the technique of X-ray absorption fine structure (XAFS) to study the oxidation state and structure of cerium in electrochemically deposited thin films of cerium oxide (hydroxide). We find that anodic deposition results in a hydrous cerium oxide phase in which the oxidation state of cerium is 4+. This material is highly structurally disordered but still has a medium range local structure (approx. 4 angstrom) similar to CeO2. On the other hand, cathodic deposition leads to a Ce3+ phase, which is susceptible to oxidation on exposure to air or by dissolved oxygen in solution. Our results may be relevant to understanding the structure of cerium inhibitors incorporated in corrosion films on aluminium and its alloys.
| Original language | English |
|---|---|
| Pages (from-to) | 178-183 |
| Number of pages | 6 |
| Journal | Thin Solid Films |
| Volume | 347 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Jun 22 1999 |
Funding
The work was supported by the US Department of Energy, Office of Environmental Management and Office of Energy Research, under Contract W-31-109-ENG-38. Financial support of this research was provided by the US Department of Energy (DOE), Office of Environmental Management and Office of Energy Research under contract No. W-31-109-ENG-38. The work at Naval Surface Warfare Center was supported by the Office of Naval Research. We acknowledge the US DOE for its role in the operation and development of NSLS and beamline X11-A. We are grateful to Dr Joseph Woicik for providing beamtime and assistance in carrying out some of the measurements at the National Institute of Standards and Technology beamline X23-A2.