Hostname: page-component-7bb8b95d7b-495rp Total loading time: 0 Render date: 2024-09-13T14:55:16.618Z Has data issue: false hasContentIssue false
  • English
  • Français

Magnetic Properties and Thermal Stability of Graphite Encapsulated Cobalt Nanocrystals

Published online by Cambridge University Press:  10 February 2011

J. J. Host  and
V. P. Dravid
J. J. Host
Affiliation:
Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208–3108
V. P. Dravid
Affiliation:
Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208–3108
Get access

Abstract

Small particles are of interest for magnetic study due to their range of magnetic properties with particle size and unusual magnetic properties. In this study we produced graphite encapsulated magnetic cobalt particles and measured their structural and magnetic properties both before and after annealing at 550° C for 6 hours. No large change in the structural properties (particle size, shape, and lattice parameter) was observed as a result of the annealing. There were, however, significant changes in the magnetic properties. The coercivity was found to decrease at all temperatures, especially at temperatures below 100° K. The possible reasons for this reduction in coercivity are examined, with the change in the shape of the particles appearing most likely.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 457: Symposium V – Nanophase and Nanocomposite Materials II , 1996 , 225
Copyright
Copyright © Materials Research Society 1997

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. Gangopadhyay, G. C., Hadjipanayis, G. C., Sorensen, C. M., and Klabunde, K. J., (Mater Res. Soc. Proc. 206, Boston, MA 1991) pg. 55. Google Scholar
2. Cullity, B. D., Introduction to Magnetic Materials, Addison-Wesley Pub. Co. (1972)Google Scholar
3. Tornita, M., Saito, Y., and Hayashi, T., Jpn. J. Appl. Phys. 32 L280 (1993)Google Scholar
4. Nelson, , Riley. Proc. Phys. Soc. London, 57 pg. 160 (1945)Google Scholar
5. Smith, W. F., Structure and Properties of Engineering Alloys McGraw-Hill Publishing Co. (1981)Google Scholar
6. Connor, , Editor, L. P.. Welding Handbook American Welding Society (1991)Google Scholar
7. Linde, , Editor, D. R.. CRC Handbook of Chemistry and Physics CRC Press (1991)Google Scholar
8. Host, J. J., Teng, M. H., Elliott, B. R., Hwang, J. H., Mason, T. O., Johnson, D. L., and Dravid, V. P., “Graphite Encapsulated Nanocrystals Produced Using a Low Carbon:Metal Ratio” Submitted to Journal of Materials Research, 4/25/96Google Scholar
9. Bozorth, R. M., Ferromagnetism D. Van Nostrand Co. (1951)Google Scholar
10. Sucksmith, W., F.R.S., and Thompson, J. E., Proc. Roy. Soc. A, 254, pg. 362 Google Scholar