Spin‐glass behavior of spinel iron oxide particles on iron metal particle recording media
| Autor: | F. T. Parker, Ami E. Berkowitz, Frederick E. Spada, T. J. Cox |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Acicular
Spin glass Materials science Condensed matter physics Spinel Oxide Iron oxide General Physics and Astronomy Mineralogy engineering.material Condensed Matter::Materials Science chemistry.chemical_compound Magnetization chemistry engineering Particle Condensed Matter::Strongly Correlated Electrons Particle size |
| Zdroj: | Journal of Applied Physics. 77:5853-5864 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | Small (30 A diameter) spinel iron oxide particles which form the protective layer on acicular iron metal particle recording media are found to exhibit no observable magnetization. The typical experimental decrease in sample magnetization for several media specimens is about 3% from 5 to 300 K. This change is the same as the thermal decrease in metal core magnetization, determined by Mossbauer spectroscopy. The predicted decrease in sample magnetization assuming normal spinel oxide behavior is typically about 20%. Two intraparticle models for reduced magnetization in oxide nanoparticles are found to be incompatible with the magnetization data. An interparticle ‘‘super‐spin‐glass’’ model is compatible with the magnetization data. The alignment between adjacent oxide nanoparticle moments is hypothesized to depend on the particular sublattices in contact, since the sublattice exchange interactions are all antiferromagnetic. An inverse particle size dependence is thus expected, in agreement with spinel oxide magnetization reduction and other phenomena seen in a wide range of studies on larger oxide particles and films. |
| Databáze: | OpenAIRE |
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