Abstract
The arrangement of spins at interfaces in a layered magnetic material often has an important effect on the properties of the material. One example of this is the directional coupling between the spins in an antiferromagnet and those in an adjacent ferromagnet, an effect first discovered1 in 1956 and referred to as exchange bias. Because of its technological importance for the development of advanced devices such as magnetic read heads2 and magnetic memory cells3, this phenomenon has received much attention4,5. Despite extensive studies, however, exchange bias is still poorly understood, largely due to the lack of techniques capable of providing detailed information about the arrangement of magnetic moments near interfaces. Here we present polarization-dependent X-ray magnetic dichroism spectro-microscopy that reveals the micromagnetic structure on both sides of a ferromagnetic–antiferromagnetic interface. Images of thin ferromagnetic Co films grown on antiferromagnetic LaFeO3 show a direct link between the arrangement of spins in each material. Remanent hysteresis loops, recorded for individual ferromagnetic domains, show a local exchange bias. Our results imply that the alignment of the ferromagnetic spins is determined, domain by domain, by the spin directions in the underlying antiferromagnetic layer.
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References
Meiklejohn, W. H. & Bean, C. P. New magnetic anisotropy. Phys. Rev. 102, 1413–1414 (1956).
Tsang, C. et al. Design, fabrication and testing of spin-valve read heads for high density recording. IEEE Trans. Mag. 30, 3801–3806 (1994).
Parkin, S. S. P. et al. Exchange-biased magnetic tunnel junctions and application to non-volatile magnetic random access memory. J. Appl. Phys. 85, 5828–5833 (1999).
Nogués, J. & Schuller, I. K. Exchange bias. J. Magn. Magn. Mater. 192, 203– 232 (1999).
Berkowitz, A. E. & Takano, K. Exchange anisotropy—a review. J. Magn. Magn. Mater. 200, 552– 570 (1999).
Locquet, J.-P., Catana, A., Mächler, E., Gerber, C. & Bednorz, J. G. Block-by-block deposition: A new growth method for complex oxide thin films. Appl. Phys. Lett. 64, 372–374 ( 1994).
Locquet, J.-P. et al. Doubling the critical temperature of La1.9Sr 0.1CuO4 using epitaxial strain. Nature 394, 453–456 (1998).
Scholl, A. et al. Observation of antiferromagnetic domains in epitaxial thin films. Science 287, 1014–1016 (2000).
Anders, S. et al. Photoemission electron microscope for the study of magnetic materials. Rev. Sci. Instrum. 70, 3973– 3981 (1999).
Stöhr, J., Padmore, H. A., Anders, S., Stammler, T. & Scheinfein, M. R. Principles of x-ray magnetic dichroism spectromicroscopy. Surf. Rev. Lett. 5, 1297–1308 (1998).
Stöhr, J. et al. Element specific magnetic microscopy with circularly polarized X-rays. Science 259, 658– 661 (1993).
Takano, K. et al. Interfacial uncompensated antiferromagnetic spins: role of unidirectional anisotropy in polycrystalline Ni81Fe19/CoO bilayers. Phys. Rev. Lett. 79, 1130– 1133 (1997).
Eibschütz, M., Shtrikman, S. & Treves, D. Mössbauer studies of Fe57 in orthoferrites. Phys. Rev. 156, 562–577 (1967).
Acknowledgements
This work was supported by the Director, Office of Basic Energy Sciences, of the US Department of Energy. J.W.S. and F.N. acknowledge support by the Swiss National Science Foundation.
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Nolting, F., Scholl, A., Stöhr, J. et al. Direct observation of the alignment of ferromagnetic spins by antiferromagnetic spins. Nature 405, 767–769 (2000). https://doi.org/10.1038/35015515
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DOI: https://doi.org/10.1038/35015515
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