| Autor: |
Peter Skeldon, Hiroki Habazaki, S.J. Garcia-Vergara, G.E. Thompson |
| Rok vydání: |
2008 |
| Předmět: |
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| Zdroj: |
Corrosion Science. 50:3179-3184 |
| ISSN: |
0010-938X |
| DOI: |
10.1016/j.corsci.2008.08.033 |
| Popis: |
The behaviour of Nd 3+ ions is examined in porous anodic alumina films formed at 5 mA cm −2 in 0.4 M phosphoric acid at 293 K on aluminium substrates that contain a buried 5 nm-thick tracer band of Al–Nd alloy. The Nd 3+ ions migrate outward in the barrier region about twice as fast as Al 3+ ions. The neodymium was located in the anodic film by transmission electron microscopy and scanning electron microscopy, and quantified by Rutherford backscattering spectroscopy. The Nd 3+ ions migrated to the cell walls and to pore base, depending upon their location in the substrate relative to the alumina cells and pores. Nd 3+ ions that reached the pore base were lost to the electrolyte. The outward transport of the Nd 3+ ions was greatest beneath the pores and least at the cell boundaries, resulting in transformation of the planar tracer layer of the substrate to a roughly hemispherical shape in the film. The behaviour contrasts with that of a tracer band of slowly migrating W 6+ ions, which reveals an approximately inverse distribution, while W 6+ ions are retained within the film. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect