Qualitative Considerations on Transition Metal Compounds

Part of the NATO ASI Series book series (NSSB, volume 184)


In many semi quantitative considerations on transition metal compounds, the Coulomb interaction between two electrons at one atom is represented by the so-called “Hubbard U”. U is also the energy necessary for charge transfer, i.e. the energy of the chemical reaction M(dn) + M(dn) → M(dn+1) + M(dn-1). For a reaction between free ions Uat = In+1 - In, where In is the ionization energy of an ion M(dn). For free ions In+1 > In, so that U > 0. In a solid (or liquid) the interaction between two electrons on the same atom is screened: U = Uat + ΔUscr., due to at scr. interaction with the surroundings. This screening is a result of the polarization of the neighbouring atoms, and has contributions from vibronic and electronic polarization. The screening leads to a lowering of U, so that U < Uat. This screening effect is generally quite large, and ΔUscr. is usually of the same order as Uat. It is even possible that the net effect of screening is so large that U < 0 (overscreening). If this is the case, charge transfer dn + dn → dn+1 + dn-1 will occur spontaneously, and the state dn+1 + dn-1 is the more stable one.


Charge Density Wave Local Spin Auger Spectrum Transition Metal Compound Exchange Splitting 
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  1. 1).
    D.K.G. de Boer, C. Haas and G.A. Sawatzky, J. Phys. F.: Met. Phys. 14, 2769 (1984).ADSCrossRefGoogle Scholar
  2. 2).
    J.E. Cretier and G.A. Wiegers, Mat. Res. Bull., 8, 1427 (1973).CrossRefGoogle Scholar
  3. 3).
    K. Prassides and P. Day, Inorg. Chem. 24, 1109 (1985).CrossRefGoogle Scholar
  4. 4).
    R. Eppinga, G.A. Wiegers and C. Haas, Physica 105B, 174 (1981).Google Scholar
  5. 5).
    J. Dijkstra, C.F. van Bruggen, C. Haas and R.A. de Groot, to be published.Google Scholar
  6. 6).
    C. Haas, Current Topics in Materials Science, Vol. 3, 1 (1979).Google Scholar
  7. 7).
    T.M. Rice and L. Sneddor, Phys. Rev. Letters 47, 689 (1981).ADSCrossRefGoogle Scholar
  8. 8).
    M.K. Wu, J.R. Ashburn, C.J. Torng, P.H. Hör, R.L. Meng, L. Gao, Z.J. Huang, Y.Q. Wang and C.W. Chu, Phys. Rev. Letters 58, 908 (1987).ADSCrossRefGoogle Scholar
  9. 9).
    W. Beall Fowler and R.J. Elliott, Phys. Rev. B34, 5525 (1986).ADSGoogle Scholar
  10. 10).
    J. Zaanen, C. Westra and G.A. Sawatzky, Phys. Rev. B33, 8060 (1986).ADSGoogle Scholar
  11. 11).
    O. Gunnarsson and K. Schönhammer, Phys. Rev. B28, 4315 (1983).ADSGoogle Scholar
  12. 12).
    R.A. de Groot, F.M. Mueller, P.G. van Engen and K.H.J. Buschow, Phys. Rev. Letters 50, 2024 (1983).ADSCrossRefGoogle Scholar
  13. 13).
    C. Haas, Crit. Rev. Solid State Sciences 1, 47 (1970).CrossRefGoogle Scholar
  14. 14).
    T. Kasuya, Progress Theor. Phys. (Kyoto) 6, 45 (1956).ADSCrossRefGoogle Scholar
  15. 15).
    P.G. de Gennes and J. Friedel, J. Phys. Chem. Solids 4, 71 (1958).ADSCrossRefGoogle Scholar
  16. 16).
    E.L. Nagaev, Phys. Status Sol. b65, 11 (1974).ADSCrossRefGoogle Scholar
  17. 17).
    V. Korenman, J.L. Murray and R.E. Prange, Phys. Rev. B16, 4032 (1977).ADSGoogle Scholar
  18. 18).
    P.W. Anderson and H. Hasegawa, Phys. Rev. 100, 675 (1955).ADSCrossRefGoogle Scholar
  19. 19).
    P.G. de Gennes, Phys. Rev. 118, 141 (1960).ADSCrossRefGoogle Scholar
  20. 20).
    M. Otto, H. Feil, R.A.M. van Woerden, J. Wijngaard, P.J. van der Valk, C.F. van Bruggen and C. Haas, to be published.Google Scholar

Copyright information

© Plenum Press, New York 1988

Authors and Affiliations

  • C. Haas
    • 1
  1. 1.Laboratory of Inorganic ChemistryMaterials Science CentreGroningenThe Netherlands

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