Exchange bias in a columnar nanocrystalline Ni80Fe20/CoO thin film
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Date
2007-12-28
Journal Title
Journal ISSN
Volume Title
Publisher
The American Physical Society
Abstract
The effects of interfacial coupling at the boundary of ferromagnetic and antiferromagnetic components in a nanoscale columnar-structured thin film of Ni80Fe20/CoO have been examined. Field-cooling the film results in very different temperature dependences of the enhanced coercivity and exchange-bias shift of the hysteresis loop. The exchange-bias temperature dependence is well described by thermal fluctuations of the interfacial spins while the coercivity temperature dependence indicates that single-domain-like columns are being coherently rotated by the thermal fluctuations of the interface spins. Furthermore, only a portion of the spins in the antiferromagnetic layer seem to be associated with the spin coupling that results in exchange bias. X-ray magnetic resonant scattering measurements show clearly the presence of canted Co interfacial moments that provide a local field which enables exchange bias at a significantly higher temperature than the onset of an enhanced coercivity. © 2007, American Physical Society
Description
Keywords
Antiferromagnetic materials, Anisotropy, Spin, Nanostructures, Temperature range, Asymmetry, Ferromagnetic materials, Thin films
Citation
van Lierop, J., Southern, B. W., Lin, K. W., Guo, Z. Y., Harland, C. L., Rosenberg, R. A., & Freeland, J. W. (2007). Exchange bias in a columnar nanocrystalline Ni80Fe20/CoO thin film. Physical Review B, 76(22), 224432. doi:10.1103/PhysRevB.76.224432