| Autor: |
Yamato, T., Kume, T., Kato, T., Tsunashima, S., Nakamura, T., Fujiwara, Y., Iwata, S. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 12/1/2006, Vol. 100 Issue 11, p113907, 6p, 1 Diagram, 8 Graphs |
| Abstrakt: |
(001)-oriented Ni80Fe20/Mn100-xPtx and Co90Fe10/Mn100-xPtx epitaxial bilayers were prepared using the molecular beam epitaxy method. Their exchange anisotropies were measured using a torque magnetometer, while their interfacial Mn uncompensated moments were measured by means of x-ray magnetic circular dichroism. The bilayers exhibited both one- and fourfold components in their anisotropy torque curves, which are difficult to explain using a simple model assuming the coherent rotation of ferromagnetic (F) and antiferromagnetic (AF) spins. Uncompensated Mn moments were confirmed to exist in the Mn100-xPtx layer due to exchange coupling with the adjacent F layer, and the Mn moment of CoFe/Mn100-xPtx was found to be larger than that of NiFe/Mn100-xPtx. In order to understand the experimental results, we extended the Mauri et al. [J. Appl. Phys. 62, 3047 (1987)] domain wall model by assuming cubic anisotropy in the AF and four AF domains whose interfacial moments are oriented along the principal axis of (001)-oriented Mn–Pt. The model predicted the uncompensated AF moment resulting from the domain wall formed in the AF layer and well reproduced the coexistence of one- and fourfold anisotropies in the in-plane torque curves. The uncompensated moment and torque curve were found to be dependent on the ratio of F/AF interfacial exchange coupling and the AF domain wall energy. By changing the ratio, it was possible to reproduce exchange anisotropy for various systems, such as NiFe/MnPt, NiFe/MnIr, and CoFe/MnPt. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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