Spin Fluctuations in Itinerant Frustrated Systems

  • M. Shiga
  • H. Nakamura
Part of the NATO Science Series book series (ASHT, volume 55)


Frustration of magnetic interactions gives rise to various anomalies in the magnetic structure and the critical behavior at the transition temperature. Among them, the ground state of the fully frustrated (FFR) system, which has a macroscopic number of degenerate spin configurations, is attracting much attention. The concept of the quantum spin liquid (QSL) has been proposed as a ground state of FFR. However, no examples has been found so far in ionic crystals. We have studied magnetic and thermal properties of Y(Sc)Mn2where Mn sites form FFR lattice, and found that this compound exhibits really astonishing properties; the very large γ value of 150mJ/Kmol2the enhanced thermal expansion coefficient of 50×10“-6/K etc.

In order to explain these anomalies, we proposed that the ground state of this compound may be in the QSL state, which is characterized by the existence of giant zero point spin fluctuations with antiferromagnetic correlations. Neutron scattering, NMR and µSR experiments have been done to prove this proposal. Effects of impurities, which should be remarkable for the FFR system, were studied by static and dynamical methods. It has been found that the substitution of Al for Mn gives rise to a spin-liquid to spin-glass transition, supporting the FFR characters of Y(Sc)Mn2.

Similar phenomena have been observed in (β-Mn and (β-Mn-Al alloys. It will be shown that Mn II sites in the β-Mn structure can be regarded as three-dimensional twisted Kagome lattice and so as a FFR system.


Spin Glass Spin Fluctuation Local Amplitude Antiferromagnetic Correlation Magnetic Neutron 
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  1. 1.
    Anderson, P.W. (1973)Mater. Res. Bull. 8, 153.CrossRefGoogle Scholar
  2. 2.
    Fazekas, P. and Anderson, P.W. (1974) On the ground state properties of the anisotropic triangular antiferromagnetPhil.Mag 30, 423–440.ADSCrossRefGoogle Scholar
  3. 3.
    Reimer, J.N., Greedan, J.E., Kremer, R.K., Gmelin, E., and Subramanian, M.A. (1991) Short-range magnetic ordering in the highly frustrated pyrochlore Y2Mn2O7, Phys.Rev. B 43, 3387–3394.ADSCrossRefGoogle Scholar
  4. 4.
    Moriya, T. (1979) Recent progress in the theory of itinerant electron magnetism, J.Magn. Magn. Mat. 14, I-46.CrossRefGoogle Scholar
  5. 5.
    Ballou, R., Deportes J., Lemaire, R., Nakamura, Y., and Ouladdiaf, B. (1987) Helimagnetism in the cubic Laves phase YMn2, J.Magn.Magn.Mat. 70 129–133.ADSCrossRefGoogle Scholar
  6. 6.
    Cywinsky, R., Kilcoyne, S.H., and Scott, C.A. (1991) Magnetic order and moment instability in YMn2, (1991)J.Phys.:Condens. Mater. 3, 6473–6488.ADSCrossRefGoogle Scholar
  7. 7.
    Nakamura, H, Wada, H., Yoshimura, K., Shiga, M, Nakamura, Y., Sakurai, J and Komura, Y. (1988) Effect of chemical pressure on the magnetism of YMn2, J.Phys. F18, 981–991.ADSCrossRefGoogle Scholar
  8. 8.
    Wada, H., Shiga, M., and Nakamura, Y. (1989) Low temperature specific heat of nearly ferro-and antiferromagnetic compounds, Physica B 161, 197–202.ADSCrossRefGoogle Scholar
  9. 9.
    Fisher, R.A., BalIou, R., Emerson, J.P., Lelievre-Berna, E., and Phillips, N.E. (1992) Low temperature specific heat of YMn2 in the paramagnetic and antiferromagnetic phases, Proc. Int. Conf: Physics of Transition Metals, Darmstadt, pp.830–833.Google Scholar
  10. 10.
    Bauer, E., Dubenko, I.S., Gratz, E., Hauser, R., Markosyan, A., and Payer, K (1992) Suppression of spin fluctuations in YMn2 by hydrostatic pressureProc. Int. Conf: Physics of Transition Metals, Darmstadt,World Scientific, pp.826–829.Google Scholar
  11. 11.
    Shiga, M. (1995) Spin dynamics in frustrated itinerant systemsProc. XXX Zakopane School of Physics Inst. Phys. Jagiellonian Univ. pp.57–68.Google Scholar
  12. 12.
    Mekata, M., Asano, T., Sugino, T., Nakamura, H., Asai, N., Shiga, M., Keren, A., Kojima, K., Luke, G.M., Wu, W.D., Uemura, Y.J., Dunsinger, S., and Gingras, M. (1995) Is Y(Sc) Mn2 really a quantum spin liquid?J.Magn.Magn.Mat.140–144, 1767–1768.ADSCrossRefGoogle Scholar
  13. 13.
    Shiga, M., Wada, H., Nakamura, Y., Deportes, J., Ouladdiaf, B and Ziebeck, K.R.A. (1988) Giant spin fluctuations in Y0.92Sc0.03Mn2 J. Phys. Soc. Jpn. 57, 3141–3145.ADSCrossRefGoogle Scholar
  14. 14.
    Takahashi, Y. (1990) Magneto-volume effects in weakly ferromagnetic metals, J.Phys. Condens. Matter 2, 8405–8415.ADSCrossRefGoogle Scholar
  15. 15.
    Lacroix, C., Solontsov, A., and Ballou, R. (1996) Spin fluctuations in itinerant electron antiferromagntism and anomalous properties of Y(Sc)Mn2 Phys.Rev. B54, 15178–15184.ADSGoogle Scholar
  16. 16.
    Ballou, R., Lelievre-Berna, E., and Fak, B. (1996) Spin fluctuations in (Y0.97Sc0.03)Mn2: A geometrically frustrated, nearly antiferromagfnetic, itinerant electron system, Phys.Rev.Letters 67, 2125–2128.ADSCrossRefGoogle Scholar
  17. 17.
    Nakamura, H., Yoshimoto, K., Shiga, M., Nishi, M., and Kakurai, K. (1997) Strong antiferromagnetic spin fluctuations and the quantum spin-liquid state in geometrically frustrated 13-Mn, and the transition to a spin-glass state caused by non-magnetic impurity, J. Phys. Condens. Mater. 9, 4701–4728.ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 1998

Authors and Affiliations

  • M. Shiga
    • 1
  • H. Nakamura
    • 1
  1. 1.Department of Materials Science and EngineeringKyoto UniversitySakyo-ku, KyotoJapan

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