| Autor: |
Chia-Ling Chien, Yu. P. Kabanov, Robert D. Shull, V. I. Nikitenko, J. S. Jiang, V. S. Gornakov, Alexander J. Shapiro, S. D. Bader |
| Rok vydání: |
2003 |
| Předmět: |
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| Zdroj: |
Journal of Magnetism and Magnetic Materials. :19-24 |
| ISSN: |
0304-8853 |
| DOI: |
10.1016/s0304-8853(02)00998-8 |
| Popis: |
The elementary events of the remagnetization processes in nanocomposite magnetic bilayers were investigated using iron-garnet indicator films with in-plane anisotropy. We have observed hybrid domain walls consisting of both ferromagnetic and antiferromagnetic sections perpendicular to the interface. The external magnetic field shifts only the ferromagnetic part of the domain walls. This leads to the formation of a hybrid exchange spin spring parallel to the interface. The processes of spring nucleation and untwisting occur at different locations. With the field oriented antiparallel to the macroscopic unidirectional anisotropy, remagnetization of the soft ferromagnet layer in the hard/soft nanocomposite starts by the formation of an exchange spring consisting of micrometer-scale sub-domains with opposite direction spin twisting. A rotating magnetic field (smaller than some critical value) creates firstly a single-chiral spin spiral; this spiral then loses stability, incoherently untwists and gradually inverts its chirality with increasing field rotation. Untwisting of the hybrid exchange spring at higher fields leads to the creation of unusual hybrid non-180° domain walls. The initial (ground) state of the bilayer with such noncollinear magnetized domains is not restored after stopping the field rotation and returning it to zero. The revealed phenomena are attributed to the influence of the dispersion in the unidirectional anisotropy induced by magnetization frustration in the interface and bilayer crystal lattice defects. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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