Cation Distribution and Non-Stoichiometry in MnCr2O4,-NiCr2O4 Spinel Solid-Solitions

  • C. Karataş
Part of the NATO ASI Series book series (ASIC, volume 276)


Cation distribution in MnCr2O4.NiCrO4 spinel solid-solutions at 1300°C was calculated using non-linear disordering enthalpies obtained from the experimental cation distribution of Mn2+, Mn2+, Cr2+, Cr3+, Ni2+ and assuming random mixing on both tetrahedral and octahedral sites.The model also incorporates the electron exchange reaction:
$$M{n^{2 + }}C{r^{3 + }} = M{n^{3 + }} + C{r^{2 + }}$$
as well as site exchanges of newly formed cations. The Gibbs free energy of mixing derived from the available experimental data obtained in our.laboratory are discussed in conduction with the values calculated from the cation distribution model as the free energy of electron exchange reaction being a parameter. The effect of size mismatch of the substituting cations was taken into account using a solution model. Observed positive deviations from ideality suggests a miscibility gat, at lower temperatures.


Free Energy Octahedral Site Tetrahedral Site Cation Distribution Configurational Entropy 
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  1. 1.
    H.O’Neill and A.Navrotsky, American Minereologist, 69,733(1984).Google Scholar
  2. 2.
    A.Navrotsky, American Minereologist, 71,1160(1986).Google Scholar
  3. 3.
    A.Navrotsky, B.Wechsler, K.Geisinger and F.Seifert, J.Am.Ceram. Soc., 69,418(1986).CrossRefGoogle Scholar
  4. 4.
    K.T.Jacob, G.N.K.Iyengar and W.K.Kim, J.Am.Ceram.Soc.,69,487(1986).CrossRefGoogle Scholar
  5. 5.
    T.O.Mason, J.Am.Ceram.Soc.,68,C-74(1985).CrossRefGoogle Scholar
  6. 6.
    N.Koç, M.Timuçin, Master Thesis, Middle East Technical University, Ankara,Turkey, January(1981).Google Scholar
  7. 7.
    K.J.Jacob and K.Fitzner, J.Mat.Sci.12,481(1977).CrossRefGoogle Scholar
  8. 8.
    B.Boucher, R.Buhl and M.Perring, J.Phys.Chem.Solids,32,1471(1971).CrossRefGoogle Scholar
  9. 9.
    C.P.Marshall and W.A.Dollase, Am.Min.69,928(1984).Google Scholar
  10. 10.
    N.Renault, N.Buffier and M.Huber, J.Solid State Chem.5,250(1972).CrossRefGoogle Scholar
  11. 11.
    B.J.Wood, In R.C.Newton, A.Navrotsky and B.J.Wood, Eds., Thermodynamics of Minerals (1981).Google Scholar
  12. 12.
    J.F.Elliot and M.Gleiser, Thermochemistry for Steelmaking. Addison-Wesley Co.Inc.,(1960).Google Scholar
  13. 13.
    O.Kubachewki, E.Evans, Metalurgical Thermochemical, Pergamon Press, London(1968).Google Scholar
  14. 14.
    H.Ohnishi and T.Terenasu, J.Phys.Soc.Japan,16,35(1961).CrossRefGoogle Scholar
  15. 15.
    J.D.Dunitz, L.E.Orgel, J.Phys.Chem.Solids,3,318(1957).CrossRefGoogle Scholar
  16. 16.
    D.McClure, J.Phys.Chem.Solids,3,311(1957).CrossRefGoogle Scholar
  17. 17.
    R.D. Shannon and C.T. Prewitt, Acta Crystallogr.B25,925(1969).Google Scholar
  18. 18.
    C.Wagner, Thermodynamics of Alloy, Addison-Wesley, Co.Inc.,(1952).Google Scholar
  19. 19.
    K.T.Jacob and C.B.Alcock, J.Solid State Chem.,20,79(1977).CrossRefGoogle Scholar
  20. 20.
    C.Glidewell, Inorganica Chimica Acta 19,L45(1976.).CrossRefGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1989

Authors and Affiliations

  • C. Karataş
    • 1
  1. 1.Hacettepe University-Nuclear Engineering DepartmentBeytepe, AnkaraTurkey

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