Advertisement

Magnetic and Thermal Properties of Dy3Al5O12 as a Magnetic Refrigerant

  • R. Li
  • T. Numazawa
  • T. Hashimoto
  • A. Tomokiyo
  • T. Goto
  • S. Todo
Part of the Advances in Cryogenic Engineering Materials book series (ACRE, volume 32)

Abstract

We investigated the magnetic entropy of Dy3AlsO12 (DAG), which is one of the most promising refrigerants for the Carnot-type magnetic refrigerator. In the present investigation we measured the specific heat in zero magnetic field and the magnetization as a function of temperature and magnetic field, and from the analysis of these experimental results, the magnetic entropy change ΔSJ and entropy S are obtained. The values of ΔSJ and S of DAG were compared with those of Gd3Ga5O12(GGG), which is frequently used as a refrigerant for the Carnot-type magnetic refrigerator. The g-factor of the magnetic ion in DAG was shown to play a more important role in determining ΔSJ near 20 K than the J-value. It is therefore clear that DAG is a more useful refrigerant than GGG for the Carnot-type refrigerator having a broad temperature span from ~20 K to 4.2 K.

Keywords

Magnetic Field Magnetic Field Strength Total Entropy Magnetocaloric Effect Magnetic Entropy Change 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Forinstance, A. F. Lacaze, R. Béranger, G. Bon Mardion, G. Claudet and A. A. Lacaze, Double acting reciprocating magnetic refrigerator: recent improvements, in: “Advances in Cryogenic Engineering”, vol. 29, Plenum Press, New York (1983), pp. 573–579.Google Scholar
  2. 2.
    Forinstance, H. Nakagome, N. Tanji, O. Horigami, H. Ogiwara, T. Numazawa, Y. Watanabe and T. Hashimoto, The helium magnetic refrigerator I: Development and experimental results, in: “Advances in Cryogenic Engineering”, vol. 29, Plenum Press, New York (1983), pp. 581–587.Google Scholar
  3. 3.
    Y. Hakuraku and H. Ogata, Conceptual design of a new magnetic refrigerator operating between 4 K and 20 K, Submitted to Jan. J. Appl. Phys. Google Scholar
  4. 4.
    T. Numazawa, Y. Watanabe, T. Hashimoto, A. Sato, H. Nakagome, O. Horigami, S. Takayama and M. Watanabe, The magnetic refrigeration characteristics of several magnetic refrigerants below 20 K: II Thermal properties, in “ICEC9, Kobe, Japan, 1982”, Butterworth, UK, pp. 30–33.Google Scholar
  5. 5.
    T. Hashimoto, T. Numazawa, Y. Watanabe, A. Sato, H. Nakagome, O. Horigami, S. Takayama and M. Watanabe, The magnetic refrigeration characteristics of several magnetic refrigerants below 20 K: I Magnetocaloric effect, in “ICEC9, Kobe, Japan, 1982”, Butterworth, UK, pp. 26–29.Google Scholar
  6. 6.
    T. Numazawa, M. Ikisawa, T. Hashimoto, A. Tomokiyo, The magnetocaloric and thermal properties of garnet type magnetic refrigerants between 4 K and 30 K, to be published in ICMC. 1985.Google Scholar
  7. 7.
    J. A. Barclay, A 4 K to 20 K rotational-cooling magnetic refrigerator capable of 1 mW to > 1 W operation, Cryogenics, 20:467–471 (1980).CrossRefGoogle Scholar
  8. 8.
    G. A. Slack and D. W. Oliver, Thermal conductivity of garnets and phonon scattering by rare-earth ions, Phys. Rev. B. 4:592–609 (1971).CrossRefGoogle Scholar
  9. 9.
    T. Hashimoto, T. Numazawa, M. Shiino and T. Okada, Magnetic refrigeration in the temperature range from 10 K to room temperature: the ferromagnetic refrigerants, Cryogenics, 21:647–653 (1981).CrossRefGoogle Scholar
  10. 10.
    W. P. Wolf, B. Schneider, D. P. Landau and B. E. Keen, Magnetic and thermal properties of dysprosium aluminum garnet II. Characteristic parameters of an ising anti-ferromagnet, Phys. Rev. B. 5:4472–4496 (1972).CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1986

Authors and Affiliations

  • R. Li
    • 1
  • T. Numazawa
    • 1
  • T. Hashimoto
    • 1
  • A. Tomokiyo
    • 2
  • T. Goto
    • 3
  • S. Todo
    • 3
  1. 1.Department of Applied PhysicsTokyo Institute of TechnologyOh-okayama, Meguro, TokyoJapan
  2. 2.College of General EducationKyushu UniversityChuoku, FukuokaJapan
  3. 3.Institute for Solid State PhysicsUniversity of TokyoMinatoku, TokyoJapan

Personalised recommendations