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Self-organization of magnetic nanogroove arrays by LaserMBE and hydrogen reduction.

Published online by Cambridge University Press:  26 February 2011

Akifumi Matsuda ,
Takahiro Watanabe ,
Yasuyuki Akita ,
Makoto Hosaka ,
Kouji Koyama ,
Atsuko Takeuchi  and
Mamoru Yoshimoto
Akifumi Matsuda
Affiliation:
matsuda.a.aa@m.titech.ac.jp, Tokyo Institute of Technology, Department of Innovative and Engineered Materials, 4259-J2-46 Nagatsuta, Midori, Yokohama, 226-8503, Japan, +81-45-924-5331, +81-45-924-5365
Takahiro Watanabe
Affiliation:
watanabe.t.al@m.titech.ac.jp, Tokyo Institute of Technology, Dept. of Innovative and Engineered Materials, 4259-J2-46 Nagatsuta, Midori, Yokohama, 226-8503, Japan
Yasuyuki Akita
Affiliation:
akita.y.aa@m.titech.ac.jp, Tokyo Institute of Technology, Dept. of Innovative and Engineered Materials, 4259-J2-46 Nagatsuta, Midori, Yokohama, 226-8503, Japan
Makoto Hosaka
Affiliation:
hosaka.m.ab@m.titech.ac.jp, Tokyo Institute of Technology, Dept. of Innovative and Engineered Materials, 4259-J2-46 Nagatsuta, Midori, Yokohama, 226-8503, Japan
Kouji Koyama
Affiliation:
k-koyama@namiki.co.jp, Namiki Precision Jewel Co., Ltd., 3-8-22 Shinden, Adachi, Tokyo, 123-8511, Japan
Atsuko Takeuchi
Affiliation:
takeuchi@namikipj.com, Namiki Precision Jewel Co., Ltd., 3-8-22 Shinden, Adachi, Tokyo, 123-8511, Japan
Mamoru Yoshimoto
Affiliation:
yoshimoto.m.aa@m.titech.ac.jp, Tokyo Institute of Technology, Dept. of Innovative and Engineered Materials, 4259-J2-46 Nagatsuta, Midori, Yokohama, 226-8503, Japan
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Abstract

The epitaxially grown magnetic nanostructures including nanodots, nanowires and nanorings have been attracting much scientific and engineering interests because of their expected unique physical characteristics due to quantum effects. These epitaxial nanomagnets and their array are undoubtedly thought to make major contribution to the development of future SPINTRONICS devices, ultra-high density magnetic random access memory (MRAM) and magnetic switching devices for examples, and other quantum devices. In this case, epitaxial growth of the nanomagnets and the resulting anisotropic properties are one of the largest interest as well as fine-nanostructuring. There have been some concerns such as throughput rate with conventional nanoprocessing techniques involving FIB lithography and e-beam lithography, and/or minimization-limit with photolithography due to the wavelength. On the other hand, self-assembly or self-organized methods could also be used for construction of nanopatterns, in which such nanostructures are directly built up from separate atoms. Here we report about formation and characterization of self-organized nanomagnet arrays made of metals and oxides. We have epitaxially grown ferrimagnetic Fe3O4 (111), (Mn0.55Zn0.35Fe0.10)Fe2O4 (111), ferromagnetic Ni (111) and antiferromagnetic NiO (111) nanodots, nanowires and nanogroove arrays on the atomically stepped ultra-smooth sapphire (0001) substrate by LaserMBE. The sapphire (a-Al2O3 single crystal) substrates have atomic steps of 0.2 nm in height and atomically flat terraces of 50-100 nm in width so that self-assembly processes of nanomagnet arrays were strongly induced by the energetic instability at the straight and periodic step-edges. In this study, NiO worked as a antiferromagnetic exchange bias layer. On the other hand, NiO was also reduced into ferromagnetic Ni metal by annealing in hydrogen atmosphere in some situations for further applications. Crystallographic and morphology analyses of the nanomagnets were made by in-situ reflection high-energy electron diffraction (RHEED), ex-situ X-ray diffraction (XRD), transmission electron microscope (TEM). and atomic force microscopy (AFM). Magnetic properties were characterized by superconducting quantum interference device (SQUID) magnetometer and magnetic force microscopy (MFM). Further experimentals are conducted for magneto-optical characterizations for above mentioned metal and/or oxide nanomagnet arrays.

Keywords

magneticnanostructureepitaxy
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1032: Symposium I – Nanoscale Magnetic Materials and Applications , 2007 , 1032-I05-06
Copyright
Copyright © Materials Research Society 2008

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References

1. Prinz, G. A., Science 282, 1660 (1998).10.1126/science.282.5394.1660Google Scholar
2. Sarma, S. D., Fabian, J., Hu, X., and Zutic, I., Issues, concepts, and challenges in spintronics, Superlattices Microstruct. 27, 95 (2000).Google Scholar
3. Boeck, J. D. and Borghs, G., Magnetoelectronic devices, Tech. Dig. Int. Elec. Dev. Meet. 215 (1999).Google Scholar
4. Kumar, D., Zhou, H., Nath, T. K., Kvit, V., and Narayan, J., Appl. Phys. Lett. 79, 2817 (2001).10.1063/1.1412428Google Scholar
5. Kaya, S., Sci. Rep. Tohoku Imp. Univ. 17, 629 (1928).Google Scholar
6. Debelle, A., Abadias, G., Michel, A., Jaouen, C., Gúerin, P., Marteau, M., and Drouet, M., Mater. Res. Soc. Symp. Proc. 875, O14.4.1 (2005).Google Scholar
7. Kang, H. C., Seo, S. H., Jang, H. W., Kim, D. H., and Noh, D. Y., Appl. Phys. Lett. 83, 2139 (2003).10.1063/1.1610248Google Scholar
8. Lukaszew, R. A., Stoica, V., Uher, C., and Clarke, R., Mater. Res. Soc. Symp. Proc. 648, P3.29.1 (2001).Google Scholar
9. Zhang, Z., Lukaszew, R. A., Cionca, C., Pan, X., Clarke, R., Yeadon, M., Zambano, A., Walko, D., Dufresne, E., and Velthius, S. te, J. Vac. Sci. Technol. A 22, 1868 (2004).10.1116/1.1692292Google Scholar
10. Zhou, H., Kumar, D., Kvit, A., Tiwari, A., and Narayan, J., J. Appl. Phys. 94, 4841 (2003).10.1063/1.1609046Google Scholar
11. Matsuda, A., Akiba, S., Kasahara, M., Watanabe, T., Akita, Y., Y, Kitamoto, Tojo, T., Kawaji, H., Atake, T., Koyama, K., and Yoshimoto, M., Thin Solid Films (in press)Google Scholar
12. Wang, J., Cai, J., Lin, Y., and Nan, C., Appl. Phys. Lett. 87, 202501 (2005).10.1063/1.2130532Google Scholar
13. Lin, Y., Zhao, R., Nan, C., and Ying, M., Appl. Phys. Lett. 89, 202501 (2006).10.1063/1.2388130Google Scholar
14. Klein, M. F., IEEE Trans. Semicond. Manuf. 1, 28 (1988).10.1109/66.4370Google Scholar
15. Arisha, A., Young, P., and Baradie, M. El, J. Mater. Process. Technol. 155–156, 2071 (2004).Google Scholar
16. Chen, A., Chua, S. J., Chen, P., Chen, X. Y., and Jian, L. K., Nanotechnology 17, 3903 (2006).10.1088/0957-4484/17/15/048Google Scholar
17. Daniel, P. J., Inst. Phys. Conf. Ser. 57, 169 (1981).Google Scholar
18. Trybula, W., Wright, R. L., and Goodall, R. K., Proc. Winter Simul. Conf., 2218 (2005).Google Scholar
19. Morimoto, H., Sasaki, Y., Saitoh, K., Watanabe, Y., and Kato, T., Microelectron. Eng. 4, 163 (1986).10.1016/0167-9317(86)90009-2Google Scholar
20. Matsui, S., Kojima, Y., Ochiai, Y., Honda, T., and Suzuki, K., Microelectron. Eng. 11, 427 (1990).10.1016/0167-9317(90)90144-IGoogle Scholar
21. Yoshimoto, M., Sasaki, A., and Akiba, S., Sci. Tech. Adv. Mater. 5, 527 (2004).Google Scholar
22. Takakura, M., Miyahara, T., Tashiro, J., Sasaki, A., Furusawa, M., and Yoshimoto, M., Mater. Res. Soc. Proc. 648, P6.5.1 (2001).Google Scholar
23. Yoshimoto, M., Mizuno, K., and Miyahara, T., Mater. Res. Soc. Proc. 587, O3.1.1 (2000).Google Scholar
24. Sasaki, A., Akiba, S., Matsuda, A., Hara, W., Sato, S., and Yoshimoto, M., Jpn. J. Appl. Phys. 44, 256 (2005).10.1143/JJAP.44.L256Google Scholar
25. Sakata, O., Kitano, A., Yashiro, W., Sakamoto, K., Miki, K., Matsuda, A., Hara, W., Akiba, S., and Yoshimoto, M., Mater. Res. Soc. Proc. 840, Q6.4.1 (2005).Google Scholar
26. Sakata, O., Takata, M., Suematsu, H., Matsuda, A., Akiba, S., Sasaki, A., and Yoshimoto, M., Appl. Phys. Lett. 84, 4239 (2004).10.1063/1.1756207Google Scholar
27. Akiba, S., Matsuda, A., Isa, H., Kasahara, M., Sato, S., Watanabe, T., Hara, W., and Yoshimoto, M., Nanotechnology 17, 4053 (2006).10.1088/0957-4484/17/16/010Google Scholar
28. Gupta, A., Braren, B., Casey, K. G., Hussey, B. W., and Kelly, R., Appl. Phys. Lett. 59, 1302 (1991).10.1063/1.105481Google Scholar
29. Yoshimoto, M., Maeda, T., Ohnishi, T., Ishiyama, O., Shinohara, M., Kubo, M., Miura, R., Miyamoto, A., and Koinuma, H., Appl. Phys. Lett. 67, 2615 (1995).10.1063/1.114313Google Scholar
30. Matsuda, A., Akiba, S., Kasahara, M., Watanabe, T., Akita, Y., and Yoshimoto, M., Appl. Phys. Lett. 90, 182107 (2007).10.1063/1.2735677Google Scholar