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Permanent Magnetism in Exchange-Coupled Nanocomposites

Published online by Cambridge University Press:  21 February 2011

R. Skomski ,
J. P. Liu  and
D.J. Sellmyer
R. Skomski
Affiliation:
Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, NE 68588-0113, U.S.A
J. P. Liu
Affiliation:
Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, NE 68588-0113, U.S.A
D.J. Sellmyer
Affiliation:
Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, NE 68588-0113, U.S.A
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Abstract

The magnetic properties of permanent magnetic nanocomposites are investigated both experimentally and by model calculations. Rare-earth transition-metal films and nanocomposite thin films containing a L10 hard phase (PtFe) have been prepared by plasma sputtering and heat treatment. By choosing suitable heat-treatment processes a nearly ideal nanostructure and high energy products of up to about 50 MGOe have been achieved for the Fe-Pt system. The behavior of the nanocomposites is discussed in terms of a model applicable to nearly ideal magnets, where there are no pronounced shoulders in the hysteresis loops. Analytic expressions for M(H) are obtained for a number of cases, and it is discussed how the loops depend on the micromagnetic parameters of the involved phases. A novel aspect of magnetic nanostructures is that very small magnetic grains exhibit very large energy products, even if they are intrinsically soft-magnetic.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 577: Symposium H – Advanced Hard and Soft Magnetic Materials , 1999 , 335
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1. Coehoorn, R., Mooij, D.B. de, and Waard, C. de, J. Magn. Magn. Mater. 80 (1989) 101.Google Scholar
2. Skomski, R. and Coey, J. M. D., Phys. Rev. B 48 (1993) 15812.Google Scholar
3. Al-Omari, A. and Sellmyer, D. J., Phys. Rev. B 52 (1995) 3441.Google Scholar
4. Kneller, E. F., IEEE Trans. Magn. 27 (1991) 3588.Google Scholar
5. Parhofer, S. M., Wecker, J., Kuhrt, Ch., Gieres, G., and Schultz, L., IEEE Trans. Magn. 32 (1996) 4437.Google Scholar
6. Coey, J. M. D. (Ed.), Rare-earth Iron Permanent Magnets, University Press, Oxford 1996.Google Scholar
7. Sabiryanov, R.F., Jaswal, S.S., J. Magn. Magn. Mater. 177–181 (1998) 989.Google Scholar
8. Sabiryanov, R. F. and Jaswal, S. S., Phys. Rev. B 58 (1998) 12071.Google Scholar
9. Sellmyer, D. J. and Shan, Z. S., in: Magnetic hysteresis in novel magnetic materials (Ed.: Hadjipanayis, G. C.), Kluwer, Dordrecht 1997, pp. 419.Google Scholar
10. Liu, J.P., Liu, Y., Luo, C.P., Shan, Z.S., and Sellmyer, D.J., J. Appl. Phys. 81 (1997) 5644.Google Scholar
11. Liu, J. P., Luo, C. P., Liu, Y., and Sellmyer, D. J., Appl. Phys. Lett. 81 (1998) 5644.Google Scholar
12. Liu, J.P., Liu, Y., Shan, Z.S., and Sellmyer, D.J., IEEE Trans. Magn. 33 (1997) 3709.Google Scholar
13. Liu, J.P., Liu, Y., and Sellmyer, D.J., J. Appl. Phys. 83 (1998) 6608.Google Scholar
14. Fullerton, E. E., Jiang, J. S., Sowers, C. H., Pearson, J. E., and Bader, S. D., Appl. Phys. Lett. 72, (1998) 380.Google Scholar
15. McCormick, P. G., Miao, W. F., Smith, P. A. I., Ding, J., and Street, R., J. Appl. Phys. 83 (1998) 6256.Google Scholar
16. Astalos, R. J. and Camley, R. E., Phys. Rev. B 58 (1998) 8646.Google Scholar
17. Ping, D.H., Hono, K., and Hirosawa, S., J. Appl. Phys. 83 (1998) 7769.Google Scholar
18. Skomski, R. and Coey, J. M. D., Permanent Magnetism, Institute of Physics, Bristol and Philadelphia 1999 (in press).Google Scholar
19. Jakubowicz, J., Szlaferek, A., Jurczyk, M., J. Alloys Compounds 283 (1999) 307.Google Scholar
20. Gao, Y.-H., Zhu, J.-H., Weng, Y.-Q., Park, E. B., and Yang, Ch. J., J. Magn. Magn. Mater. 191 (1999) 146.Google Scholar
21. Skomski, R., J. Appl. Phys. 76 (1994) 7059.Google Scholar
22. Aharoni, A., Rev. Mod. Phys. 34 (1962) 227.Google Scholar
23. Kronmiller, H., phys. stat. sol. (b) (1987) 144 385.Google Scholar
24. Skomski, R., J. Appl. Phys. 83 (1998) 6503.Google Scholar
25. Skomski, R., Oepen, H.-P., and Kirschner, J., Phys. Rev. B 58 (1998) 3223.Google Scholar
26. Schrefl, T., Fidler, J., and Kronmbiller, H., Phys. Rev. B 49 (1994) 6100.Google Scholar
27. Fischer, R. and Kronmtiller, H., J. Magn. Magn. Mater. 184 (1998) 166.Google Scholar
28. Fischer, R., Leineweber, T., and Kronmtüller, H., Phys. Rev. B 57 (1998) 10723.Google Scholar
29. Christoph, V. and Elk, K., J. Magn. Magn. Mater. 74 (1988) 143.Google Scholar
30. Fukunaga, H. and Inoue, H., Jpn. J. Appl. Phys. 31 (1992) 1347.Google Scholar
31. Skomski, R., J. Magn. Magn. Mater. 157–158 (1996) 713.Google Scholar
32. Imry, Y. and Ma, Sh.-K., Phys. Rev. Lett. 35 (1975) 1399.Google Scholar
33. Sellmyer, D. J. and Nafis, S., Phys. Rev. Lett. 57 (1986) 1173.Google Scholar
34. Kuhrt, C., O'Donnell, K., Katter, M., Wecker, J., Schnitzke, K., and Schultz, L., Appl. Phys. Lett. 60 (1992) 3316.Google Scholar
35. Aharoni, A., Introduction to the Theory of Ferromagnetism, University Press, Oxford 1996.Google Scholar
36. Craik, D. J. and Isaak, E. D., Proc. Phys. Soc. 76 (1960) 160.Google Scholar
37. Mishra, R.K. and Lee, R.W., Appl. Phys. Lett. 48 (1986) 733.Google Scholar
38. Rave, W., Eckert, D., Schifer, R., Gebel, B. and Müller, K.-H., IEEE Trans. Magn. 32 (1996) 4362.Google Scholar
39. Liu, J.P., Liu, Y., Skomski, R. and Sellmyer, D.J., to be published.Google Scholar
40. Chudnovsky, E. M., Saslow, W. M., and Serota, R. A., Phys. Rev. B 33 (1986) 251.Google Scholar
41. Callen, E., Liu, Y. J., Cullen, J. R., Phys. Rev. B 16 (1977) 263.Google Scholar
42. These calculations will be published elsewhere.Google Scholar
43. Richter, J. and Skomski, R., phys. stat. sol (b) 153 (1989) 711.Google Scholar
44. Hadjipanayis, G. C. and Gong, W., J. Magn. Magn. Mater. 66 (1987) 390.Google Scholar
45. Klemmer, T., Hoydick, D., Okumura, H., Zhang, B., and Soffa, W. A., Scripta Met. Mater. 33 (1995) 1793.Google Scholar