Hostname: page-component-7479d7b7d-rvbq7 Total loading time: 0 Render date: 2024-07-13T19:19:54.589Z Has data issue: false hasContentIssue false
  • English
  • Français

Nanocomposites For magnetic Refrigeration

Published online by Cambridge University Press:  25 February 2011

R.D. Shull ,
R.D. Mcmichael ,
J.J. Ritter  and
L.H. Bennett
R.D. Shull
Affiliation:
National Institute of Standards and Technology, Materials Science and Engineering Laboratory, Gaithersburg, MD 20899
R.D. Mcmichael
Affiliation:
National Institute of Standards and Technology, Materials Science and Engineering Laboratory, Gaithersburg, MD 20899
J.J. Ritter
Affiliation:
National Institute of Standards and Technology, Materials Science and Engineering Laboratory, Gaithersburg, MD 20899
L.H. Bennett
Affiliation:
National Institute of Standards and Technology, Materials Science and Engineering Laboratory, Gaithersburg, MD 20899
Get access

Abstract

Upon the application of an external magnetic field, the magnetic spins in a material partially align with the field, thereby reducing the magnetic entropy of the spin system. When performed adiabatically, the specimen's temperature will rise. This temperature rise, δT, related to the entropy change by the heat capacity, is known as the magnetocaloric effect. Upon cycling the magnetic field, this effect can be used for transferring heat from one thermal reservoir to another, forming the basis for a magnetic refrigerator. Recently, NIST scientists predicted composite magnetic materials containing nanometer-size magnetic species could possess enhanced magnetocaloric effects [1-2], especially at high temperatures or low magnetic fields. Magnetic nanocomposites may be prepared in many different ways, and recent magnetocaloric effect data measured on Fe-doped gadolinium gallium garnets are presented to show both the effect of processing and a methodology for optimizing δT.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 286: Symposium J – Nanophase and Nanocomposite Materials , 1992 , 449
Copyright
Copyright © Materials Research Society 1993

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. Patent PendingGoogle Scholar
2. Shull, R.D., Swartzendruber, L.J., and Bennett, L.H., Proc. 6th Int. Cryocoolers Conf., eds. Green, G. and Knox, M., David Taylor Res. Cntr. Publ. #DTRC-91/002, Annapolis, MD (1991), p. 231.Google Scholar
3. Proceedings of the First International Conference on Nanostructured Materials, to be published in the J. Nanostructured Materials (1993).Google Scholar
4. Siegel, R.W., Annu. Rev. Mater. Sci. 21 (1991) 559.Google Scholar
5. Bean, C.P. and Livingston, J.D., J. Appl. Phys. 30 (1959) 120S.Google Scholar
6. Becker, J.J., Trans. Amer. Inst. Min. Engrs. 209 (1957) 59; Ibid. 212 (1958) 138.Google Scholar
7. Xiao, Gang, Liou, S.H., Levy, A., Taylor, J.N., and Chien, C.L., Phys. Rev. B 34 (1986) 7573; J.L. Dormann, L. Bessais, and D. Fiorani, J. Phys. C: Solid State Phys. 21 (1988) 2015.Google Scholar
8. McMichael, R.D., Shull, R.D., Swartzendruber, L.J., Bennett, L.H., and Watson, R.E., J. Mag. & Magn. Mat. 11, No. 1-2 (1992) 29.Google Scholar
9. Bennett, L.H., McMichael, R., Swartzendruber, L.J., Shull, R.D., and Watson, R.E., J. Magnetism & Magnetic Materials 104–107 (1992) 1094.Google Scholar
10. Shull, R.D., McMichael, R.D., Swartzendruber, L.J., and Bennett, L.H., Magnetic Properties of Fine Particles, edited by Dormann, J.L. and Fiorani, D., Elsevier Publ., Amsterdam, (1992) p. 161.Google Scholar
11. Patent PendingGoogle Scholar
12. McMichael, R.D., Ritter, J.J., and Shull, R.D., to be published in the J. Appl. Phys. (April, 1993).Google Scholar
13. Arrott, A. and Sato, H., Phys. Rev. 114, 1420 (1959).Google Scholar
14. Shull, R. D., Ritter, J. J., Shapiro, A. J., Swartzendruber, L. J., and Bennett, L. H., Multicomponent Ultrafine Microstructures, MRS Symposium Proceedings 132 (North Holland Pub. Co., N.Y., 1988), p. 179.Google Scholar