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Phase diagrams of La1−xCaxMnO3 in double exchange model with added antiferromagnetic and Jahn-Teller interaction

  • V. Michev
  • N. KarchevEmail author
Regular Article

Abstract

The phase diagram of the multivalent manganites La1−x Ca x MnO3, in space of temperature and doping x, is a challenge for the theoretical physics. It is an important test for the model used to study these compounds and the method of calculation. To obtain theoretically this diagram for x < 0.5, we consider the two-band Double Exchange Model for manganites with added Jahn-Teller coupling and antiferromagnetic Heisenberg term. In order to calculate Curie and Néel temperatures we derive an effective Heisenberg model for a vector which describes the local orientation of the total magnetization of the system. The exchange constants of this model are different for different space directions and depend on the density of e g electrons, antiferromagnetic constants and the Jahn-Teller energy. To reproduce the well known phase transitions from A-type antiferromagnetism to ferromagnetism at low x and C-type antiferromagnetism to G-type antiferromagnetism at large x, we argue that the antiferromagnetic exchange constants should depend on the lattice direction. We show that ferromagnetic to A-type antiferromagnetic transition results from the Jahn-Teller distortion. Accounting adequately for the spin fluctuations, Curie and Néel temperatures are calculated. The results are in very good agreement with the experiment and provide values for the model parameters, which best describe the behavior of the critical temperature for x < 0.5.

Keywords

Solid State and Materials 

References

  1. 1.
    N. Karchev, V. Michev, J. Phys.: Condens. Matter 19, 156212 (2007)ADSCrossRefGoogle Scholar
  2. 2.
    V. Michev, N. Karchev, Phys. Rev. B 76, 174412 (2007)ADSCrossRefGoogle Scholar
  3. 3.
    V. Michev, N. Karchev, Phys. Rev. B 80, 012403 (2009)ADSCrossRefGoogle Scholar
  4. 4.
    G.H. Jonker, J.H. Van Santen, Physica 16, 337 (1950)ADSCrossRefGoogle Scholar
  5. 5.
    J.H. Van Santen, G.H. Jonker, Physica 16, 599 (1950)ADSCrossRefGoogle Scholar
  6. 6.
    G.H. Jonker, Physica 22, 707 (1956)ADSCrossRefGoogle Scholar
  7. 7.
    E.O. Wollan, W.C. Koehler, Phys. Rev. 100, 545 (1955)ADSCrossRefGoogle Scholar
  8. 8.
    C. Zener, Phys. Rev. 81, 440 (1951)ADSzbMATHCrossRefGoogle Scholar
  9. 9.
    C. Zener, Phys. Rev. 82, 403 (1951)ADSCrossRefGoogle Scholar
  10. 10.
    P.W. Anderson, H. Hasegawa, Phys. Rev. 100, 675 (1955)ADSCrossRefGoogle Scholar
  11. 11.
    P.-G. de Gennes, Phys. Rev. 118, 141 (1960)ADSCrossRefGoogle Scholar
  12. 12.
    J.B. Goodenough, Phys. Rev. 100, 564 (1955)ADSCrossRefGoogle Scholar
  13. 13.
    A.J. Millis, P.B. Littlewood, B.I. Shraiman, Phys. Rev. Lett. 74, 5144 (1995)ADSCrossRefGoogle Scholar
  14. 14.
    H. Röder, R.R.P. Singh, J. Zang, Phys. Rev. B 56, 5084 (1997)ADSCrossRefGoogle Scholar
  15. 15.
    J. Zang, A.R. Bishop, H. Röder, Phys. Rev. B 53, R8840 (1996)ADSCrossRefGoogle Scholar
  16. 16.
    S. Yunoki, A. Moreo, E. Dagotto, Phys. Rev. Lett. 81, 5612 (1998)ADSCrossRefGoogle Scholar
  17. 17.
    D. Sarma, N. Shanthi, S. Barman, N. Hamada, H. Sawada, K. Terakura, Phys. Rev. Lett. 75, 1126 (1995)ADSCrossRefGoogle Scholar
  18. 18.
    W.E. Pickett, D.J. Singh, Europhys. Lett. 32, 759 (1995)ADSCrossRefGoogle Scholar
  19. 19.
    W.E. Pickett, D.J. Singh, Phys. Rev. B 53, 1146 (1996)ADSCrossRefGoogle Scholar
  20. 20.
    I. Solovyev, N. Hamada, K. Terakura, Phys. Rev. Lett. 76, 4825 (1996)ADSCrossRefGoogle Scholar
  21. 21.
    T. Hotta, Phys. Rev. B 67, 104428 (2003)ADSCrossRefGoogle Scholar
  22. 22.
    A.J. Millis, R. Mueller, B.I. Shraiman, Phys. Rev. B 54, 5389 (1996)ADSCrossRefGoogle Scholar
  23. 23.
    A.J. Millis, R. Mueller, B.I. Shraiman, Phys. Rev. B 54, 5405 (1996)ADSCrossRefGoogle Scholar
  24. 24.
    Y.-F. Yang, K. Held (2009), arXiv:cond-mat/0903.2989Google Scholar
  25. 25.
    Z. Popovic, S. Satpathy, Phys. Rev. Lett. 84, 1603 (2000)ADSCrossRefGoogle Scholar
  26. 26.
    M. Stier, W. Nolting, Phys. Rev. B 75, 144409 (2007)ADSCrossRefGoogle Scholar
  27. 27.
    M. Stier, W. Nolting, Phys. Rev. B 78, 144425 (2008)ADSCrossRefGoogle Scholar
  28. 28.
    N.D. Mermin, H. Wagner, Phys. Rev. Lett. 17, 1133 (1966)ADSCrossRefGoogle Scholar
  29. 29.
    D. Pekker, S. Mukhopadhyay, N. Trivedi, P.M. Goldbart, Phys. Rev. B 72, 075118 (2005)ADSCrossRefGoogle Scholar
  30. 30.
    D.I. Golosov, Phys. Rev. B 71, 014428 (2005)ADSCrossRefGoogle Scholar
  31. 31.
    S.-W. Cheong, H.Y. Hwang, in Colossal Magnetoresistance Oxides, edited by Y. Tokura (1999)Google Scholar
  32. 32.
    H. Fujishiro, T. Fukase, M. Ikebe, J. Phys. Soc. Jpn 70 628 (2001)ADSCrossRefGoogle Scholar
  33. 33.
    H. Fujishiro, M. Ikebe, in Physics in Local Lattice Distortion, edited by H. Oyanagi, A. Bianconi (2001), p. 433Google Scholar
  34. 34.
    H. Kawano, R. Kajimoto, M. Kubota, H. Yoshizawa, Phys. Rev. B 53, R14709 (1996)ADSCrossRefGoogle Scholar
  35. 35.
    P. Schiffer, A.P. Ramirez, W. Bao, S.-W. Cheong, Phys. Rev. Lett. 75, 3336 (1995)ADSCrossRefGoogle Scholar
  36. 36.
    T. Hotta, M. Moraghebi, A. Feiguin, A. Moreo, S. Yunoki, E. Dagotto, Phys. Rev. Lett. 90, 247203 (2003)ADSCrossRefGoogle Scholar
  37. 37.
    E. Dagotto, Nanoscale Phase Separation and Colossal Magnetoresistance (Springer-Verlag, Berlin, 2003)Google Scholar
  38. 38.
    K. Held, D. Vollhardt, Phys. Rev. Lett. 84, 5168 (2000)ADSCrossRefGoogle Scholar
  39. 39.
    D.P. Arovas, A. Auerbach, Phys. Rev. B 38, 316 (1988)ADSCrossRefGoogle Scholar

Copyright information

© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Department of PhysicsUniversity of SofiaSofiaBulgaria

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