Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-28T18:46:42.806Z Has data issue: false hasContentIssue false
  • English
  • Français

Hard Magnetic Nanoparticles and Nanocomposites

Published online by Cambridge University Press:  21 February 2011

Anit Giri ,
Krishna Chowdary  and
Sara A. Majetich
Anit Giri
Affiliation:
Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213
Krishna Chowdary
Affiliation:
Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213
Sara A. Majetich*
Affiliation:
Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213
*
Author to whom correspondence should be addressed. email: [email protected].
Get access

Abstract

Many high performance permanent magnets are nanostructured materials. The magnetic properties of nanoparticles are discussed in terms of characteristic length scales, including the maximum monodomain size and the exchange length. Experimental results for ball milled SmCo5 nanoparticles are presented, showing deviations from idealized behavior. Because of the short exchange length, this can be understood in terms of independent nucleation of reverse domains in grains within larger particles. With a much longer exchange length, FeCo alloy nanoparticles show reduced coercivity in a high density compact, in accordance with the random anisotropy model. The SmCo5 and FeCo nanoparticles were mixed and compacted in an attempt to make an exchange spring nanocomposite. However, significant exchange between the hard and soft phases was not observed because the sample density was too low. Processing considerations for improved co-compaction of these nanoparticles are discussed.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 577: Symposium H – Advanced Hard and Soft Magnetic Materials , 1999 , 197
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Luborsky, F. E., J. Appl. Phys. 32, 171S (1961).Google Scholar
2. Herzer, G., IEEE Trans. Mag. 25, 3327 (1989); IEEE Trans. Mag. 26, 1397 (1990); J. Magn. Magn. Mater. 112, 258 (1992).Google Scholar
3. Hadjipanayis, G. C., J. Appl. Phys. 55, 2091 (1984).Google Scholar
4. McCurrie, R. A., Ferromagnetic Materials: Structure and Properties, Academic Press, NY, 1994, p. 210.Google Scholar
5. Yoshizawa, Y., Oguma, S., and Yamauchi, K., J. Appl. Phys. 64, 6044 (1988).Google Scholar
6. Stoner, E. C. and Wohlfarth, E. P., Phil. Trans. Roy. Soc. London A240, 599 (1948).Google Scholar
7. Chikazumi, S., Physics of Magnetism, Wiley, N. Y., 1964.Google Scholar
8. Kneller, E., in Magnetism and Metallurgy, eds. Berkowitz, A. and Kneller, E., Academic Press, New York, 1969, p.366.Google Scholar
9. Brown, W. F. Jr., J. Appl. Phys. 29, 470 (1958);J. Appl. Phys. 30, 130S (1959).Google Scholar
10. Kronmüller, H., in Science and Technology of Nanostructured Magnetic Materials, Hadjipanayis, G. C. and Prinz, G. A., Plenum Press, NY, 1991, p. 657.Google Scholar
11. McCurrie, R. A. and Carswell, G. P., J. Mater. Sci. 5, 825 (1970).Google Scholar
12. Coey, J. M. D., Rare Earth Iron Permanent Magnets, Oxford Univ. Press, Oxford, 1998, p. 8.Google Scholar
13. Kneller, E. and Hawig, R., IEEE Trans. Mag. 27, 3588 (1991).Google Scholar
14. Schrefl, T. and Fidler, J., J. Magn. Magn. Mater. 177–181, 970 (1998).Google Scholar
15. Jiang, J. S., Fullerton, E. E., Grimsditch, M., Sowers, C. H., and Bader, S. D., J. Appl. Phys. 83, 6238 (1998).Google Scholar
16. Liu, J. P., Liu, Y., Shan, Z. S., and Sellmyer, D. J., IEEE Trans. Mag. 33, 3709 (1997).Google Scholar
17. Coehoorn, R., Mooij, D. B. de, and Ward, C. De, J. Magn. Magn. Mater. 80, 101 (1989).Google Scholar
18. Sagawa, M., Hirosawa, S., Yamamoto, H., Fujimura, S., and Matsura, Y., Jpn. J. Appl. Phys. 26, 785 (1987).Google Scholar
19. McCallum, R. W., Kadin, A. M., Clemente, G. B., and Keem, J. E., J. Appl. Phys. 61, 3577 (1987).Google Scholar
20. McCormick, P. G., Miao, W. F., Smith, P. A. I., and Street, R., J. Appl. Phys. 83, 6256 (1998).Google Scholar
21. Schalek, R. L., Leslie-Pelecky, D., Knight, J., Sellmyer, D. J., and Axtell, S. C., IEEE Trans. Mag. 31, 3772 (1995).Google Scholar
22. Wecker, J., Katter, M., and Schultz, L., J. Appl. Phys. 69, 6058 (1991).Google Scholar
23. Ding, J., Smith, P. A. I., McCormick, P. G., Street, R., J. Magn. Magn. Mat. 161, 303 (1996).Google Scholar
24. Majetich, S. A., Chowdary, K. M., and Kirkpatrick, E. M., IEEE Trans. Mag. 34, 985 (1998); S. A. Majetich and E. M. Kirkpatrick, IEEE Trans. Mag. 33, 3721 (1997).Google Scholar
25. Handbook of Chemistry and Physics, Chemical Rubber Co. Cleveland, 1972, p. D–49.Google Scholar
26. Kumar, K., J. Appl. Phys. 63, R13 (1988).Google Scholar
27. Bartlett, R. W. and Jorgensen, P. J., J. Less-Common Metals, 37, 21 (1974).Google Scholar
28. Benz, M. G. and Martin, D. L., J. Appl. Phys. 43, 3165 (1972).Google Scholar
29. Strnat, K. J., in Ferromagnetic Materials, eds. Wohlfarth, E. P. and Buschow, K. H. J., (Elsevier, Amsterdam and New York, 1988), p. 131.Google Scholar
30. Susic, M. V., J. Serb. Chem. Soc. 62, 349 (1997).Google Scholar
31. Zijlstra, H. and Westerdorp, F. F., Solid State Commun, 7, 857 (1969).Google Scholar
32. Li, X. G., Chiba, A., and Takahashi, S., J. Appl. Phys. 81, 2895 (1997).Google Scholar
33. Klug, H. P. and Alexander, L. E., X-ray Diffraction Procedures for Polycrystalline and Amorphous Materials, (J. Wiley and Sons, New York, 1974), pp. 661–665.Google Scholar
34. Williamson, G. K. and Hall, W. H., Acta Metallurgica 1, 22 (1953).Google Scholar
35. Kirkpatrick, E. M., Ph. D. thesis, Carnegie Mellon University, 1997.Google Scholar
36. Aharoni, A., J. Appl. Phys. 30, 705 (1959); Phys. Rev. 119, 127 (1960); J. H. Wernick, Ann. Rev. Mat. Sci. 2,607 (1972).Google Scholar
37. Shimada, Y. and Kojima, H., J. Appl. Phys. 44, 5125 (1973).Google Scholar
38. Pfeifer, F. and Radeloff, C., J. Magn. Magn. Mat. 19, 190 (1980).Google Scholar
39. Viau, G., Fievet-Vincent, F., and Fievet, F., J. Mater. Chem. 6, 1047 (1996).Google Scholar
40. Alben, R., Becker, J. J. and Chi, M. C., J. Appl. Phys. 49, 1653 (1978).Google Scholar