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Domain state and exchange coupling in MnPt with Co clusters
Robert Morel1, Céline Portemont, Ariel Brenac
1CEA Grenoble, DRFMC/SP2M, 17 rue des Martyrs, 38054 Grenoble cedex 9, France. robert.morel@cea.fr
Physical Review Letters
|October 10, 2006
Summary
Exchange bias in nanometric Co clusters coupled with MnPt thin films is linked to the antiferromagnet's bulk magnetization. This finding supports the domain state model for exchange bias phenomena.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Exchange coupling is crucial for understanding magnetic heterostructures.
- Antiferromagnetic materials like MnPt are key components in spintronic devices.
- Disordered thin films present unique magnetic behaviors.
Purpose of the Study:
- To investigate the relationship between bulk magnetization of MnPt and exchange bias in Co/MnPt systems.
- To test the validity of the domain state model for exchange bias.
Main Methods:
- Field-cooling procedures were used to induce bulk magnetization in MnPt.
- Correlation analysis between MnPt bulk magnetization (M_AF) and exchange bias (H_b).
- Application of a mean-field approach to model the effective field at the interface.
Main Results:
- MnPt develops bulk magnetization (M_AF) under field-cooling.
- A direct proportionality was found between M_AF and the effective field governing exchange bias (H_b).
- The study confirms that exchange bias is correlated with the antiferromagnet's bulk magnetic state.
Conclusions:
- The domain state model for exchange bias is strongly supported by these findings.
- Exchange bias is not solely dependent on interface configuration but also on the antiferromagnet's bulk magnetic properties.
- This research provides insights into controlling and understanding exchange bias in magnetic nanostructures.
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