Stabilizing oxide layers on iron particles
| Autor: | P.H. Smit, H. Rau, W. Schnitker, P. Eckerlin |
|---|---|
| Rok vydání: | 1982 |
| Předmět: |
Materials science
Magnetic moment Spinel Iron oxide Analytical chemistry Oxide chemistry.chemical_element engineering.material equipment and supplies Condensed Matter Physics Oxygen Electronic Optical and Magnetic Materials chemistry.chemical_compound Nuclear magnetic resonance chemistry Magnetic core Mössbauer spectroscopy engineering Iron oxide cycle human activities |
| Zdroj: | Journal of Magnetism and Magnetic Materials. 30:93-98 |
| ISSN: | 0304-8853 |
| DOI: | 10.1016/0304-8853(82)90013-0 |
| Popis: | Pyrophoric iron powders at different stages of stabilization by oxygen (0–8% by weight) were annealed at 255 or 500°C up to 571 h. During this procedure the magnetic moments first decreased by some per cent and then increased above the initial values. The shape of the magnetic moment versus oxygen uptake curves remained unchanged. The increase of the magnetic moments as a function of time is correlated with a decrease of the specific surface area of the powders. The Mossbauer spectrum of partially stabilized powders is different from that observed on completely stabilized powders and shows a hitherto unknown magnetic iron oxide while X-ray investigations suggest this oxide to be a special iron deficient Fe 3 O 4 (spinel) containing vacancies on the octahedral sites distributed at random. The spins in the oxide should then be coupled in an antiparallel way to the underlying iron core in order to explain the measured magnetic moments. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|