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Measuring the magnetization of three monolayer thick Co islands and films by x-ray dichroism

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Co islands and films are characterized by x-ray magnetic circular dichroism photoemission electron microscopy. The spatial resolution capabilities of the technique together with atomic growth control permit obtaining perfectly flat triangular islands with a given thickness (3 ML), very close to an abrupt spin-reorientation transition. The magnetic domain configurations are found to depend on island size: while small islands can be magnetized in a single-domain state, larger islands show more complex patterns. Furthermore, the magnetization pattern of the larger islands presents a common chirality. By means of dichroic spectromicroscopy at the Co L absorption edges, an experimental estimate of the ratio of the spin and orbital magnetic moment for three monolayer thick films is obtained.
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© 2009 The American Physical Society. This research was partly supported by the U.S. Department of Energy under Contracts No. DE-AC04-94AL85000 and No. DE-AC02-05CH11231, by the Spanish Ministry of Education and Science under Project No. MAT2006-13149- C02-02, and by the Comunidad Autónoma de Madrid and the CSIC under Projects No. CCG07-CSIC-MAT-2030 and No. S-0505/MAT/0194.
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1. S. D. Bader, Rev. Mod. Phys. 78, 1 2006. 2. D. Sander, J. Phys.: Condens. Matter 16, R603 2004. 3. K. Ounadjela, D. Muller, A. Dinia, A. Arbaoui, P. Panissod, and G. Suran, Phys. Rev. B 45, 7768 1992. 4. D. Muller, K. Ounadjela, P. Vennegues, V. Pierron-Bohnes, A. Arbaoui, J. P. Jay, A. Dinia, and P. Panissod, J. Magn. Magn. Mater. 104-107, 1873 1992. 5. C. Liu and S. D. Bader, J. Magn. Magn. Mater. 119, 81 1993. 6. D. Li, C. Yu, J. Pearson, and S. D. Bader, Phys. Rev. B 66, 020404 2002. 7. R. Cheng, J. Pearson, H. F. Ding, V. Metlushko, S. D. Bader, F. Y. Fradin, and D. Li, Phys. Rev. B 69, 184409 2004. 8. H. F. Ding, A. K. Schmid, D. Li, K. Y. Guslienko, and S. D. Bader, Phys. Rev. Lett. 94, 157202 2005. 9. H. F. Ding, A. K. Schmid, D. J. Keavney, D. Li, R. Cheng, J. E. Pearson, F. Y. Fradin, and S. D. Bader, Phys. Rev. B 72, 035413 2005. 10. K. Himi, K. Takanashi, S. Mitani, M. Yamaguchi, D. H. Ping, K. Hono, and H. Fujimori, Appl. Phys. Lett. 78, 1436 2001. 11. C. Song, X. X. Wei, K. W. Geng, F. Zeng, and F. Pan, Phys. Rev. B 72, 184412 2005. 12. H. Hashizume, K. Ishiji, J. C. Lang, D. Haskel, G. Srajer, J. Minár, and H. Ebert, Phys. Rev. B 73, 224416 2006. 13. F. El Gabaly, S. Gallego, C. Muñoz, L. Szunyogh, P. Weinberger, C. Klein, A. K. Schmid, K. F. McCarty, and J. de la Figuera, Phys. Rev. Lett. 96, 147202 2006. 14. F. El Gabaly, K. F. McCarty, A. K. Schmid, J. de la Figuera, M. C. Muñoz, L. Szunyogh, P. Weinberger, and S. Gallego, New J. Phys. 10, 073024 2008. 15. U. Gradmann, Appl. Phys. 3, 161 1974. 16. F. El Gabaly, J. M. Puerta, C. Klein, A. Saa, A. K. Schmid, K. F. McCarty, J. I. Cerda, and J. de la Figuera, New J. Phys. 9, 80 2007. 17. T. Schmidt, S. Heun, J. Slezak, J. Diaz, K. C. Prince, G. Lilienkamp, and E. Bauer, Surf. Rev. Lett. 5, 1287 1998. 18. C. M. Schneider, K. Holldack, M. Kinzler, M. Grunze, H. Oepen, F. Schaers, H. Petersen, K. Meinel, and J. Kirschner, Appl. Phys. Lett. 63, 2432 1993. 19. M. Klaui, M. Laufenberg, L. Heyne, D. Backes, U. Rudiger, C. A. F. Vaz, J. A. C. Bland, L. J. Heyderman, S. Cherifi, A. Locatelli, T. O. Mentes, and L. Aballe, Appl. Phys. Lett. 88, 232507 2006. 20. L. Perez, A. Mascaraque, and J. de la Figuera unpublished. 21. H. Kiwata, T. Kihara, K. Ono, M. Oshima, T. Okuda, A. Harasawa, T. Kinoshita, and A. Yokoo, Surf. Rev. Lett. 9, 365 2002. 22. A. Westphalen, A. Schumann, A. Remhof, and H. Zabel, Phys. Rev. B 74, 104417 2006. 23. W. L. Ling, T. Giessel, K. Thürmer, R. Q. Hwang, N. C. Bartelt and K. F. McCarty, Surf. Sci. 570, L297 2004. 24. To further increase the signal, we have reduced the magnification of the microscope to a field of view of 20 m. The size of the x-ray beam is 20 m5 m. 25. There is also an additional uncertainty in the degree of polarization of the x-ray beam. By measuring the XMCD of a thick Co film on W 110, not shown, we have obtained anomalously low magnetic-moment values. Although this affects the absolute values, the ratio is not modified. 26. B. T. Thole, P. Carra, F. Sette, and G. van der Laan, Phys. Rev. Lett. 68, 1943 1992. 27. P. Carra, B. T. Thole, M. Altarelli, and X. Wang, Phys. Rev. Lett. 70, 694 1993. 28. C. T. Chen, Y. U. Idzerda, H.-J. Lin, N. V. Smith, G. Meigs, E. Chaban, G. H. Ho, E. Pellegrin, and F. Sette, Phys. Rev. Lett. 75, 152 1995. 29. R. Wu and A. J. Freeman, Phys. Rev. Lett. 73, 1994 1994. 30. The x-ray beam moved visibly during the time needed to acquire the complete spectra. The motion along the short direction of the x-ray beam is corrected by moving the integration window to track the illuminated area. As a rough correction to the motion of the x-ray beam along the wide direction, we add a different constant intensity to each spectrum. Each constant is chosen to give both a flat background after the L absorption edge and similar intensity between absorption edges for both spectra. After that, we normalize them dividing by the intensity of the gold mesh to account for the photon energy dependence of the monocromator transmission. 31. S. Gallego private communication. 32. N. Nakajima, T. Koide, T. Shidara, H. Miyauchi, H. Fukutani, A. Fujimori, K. Iio, T. Katayama, M. Nývlt, and Y. Suzuki, Phys. Rev. Lett. 81, 5229 1998.
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