Selective Formation of Spinel Iron Oxide in Thin Films by Complexing Agent-Assisted Sol-Gel Processing

  • Kunihiko Kojima
  • Mitsuharu Miyazaki
  • Fujio Mizukami
  • Kazuyuki Maeda


The structure of iron oxide was controlled by regulating the hydrolytic polymerization of aquo iron complexes with organic polydentate ligands such as diols. Iron oxides were prepared by calcining the precursor polymers obtained from iron nitrate nonahydrate and diols. When the diols were 1,2-pentanediol, 1,2-hexanediol and 1,2-octanediol, α -Fe2O3 with corundum structure appeared exclusively or as the main crystalline phase, in spite of the amount of diol used and the calcination temperature. In the case of 1,2-decanediol and 1,2-dodecanediol, when five moles of the diols were used to one mole of iron nitrate and the calcination temperatures were below 400° C, γ -Fe2O3 with spinel structure appeared as the main phase and, when less than five moles of the diols were used, α -Fe2O3 appeared exclusively or as the main phase, irrespective of the calcination temperature. This tendency was also observed in thin films. Thus, a transparent magnetic film composed of γ -Fe2O3 could be prepared by applying a benzene solution of the iron polymer, obtained with 5 equivalents of 1,2-decanediol, on quartz and calcining the gel film at 350° C.

iron oxide structural control complexing agent thin film sol-gel 


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  1. 1.
    R.B. Heslop and P.L. Robinson, Inorganic Chemistry (Elsevier, Maruzen Asian Edition, Japan, 1960), p. 465.Google Scholar
  2. 2.
    C.M. Flynn, Jr., Chem. Rev. 84, 31 (1984).Google Scholar
  3. 3.
    F. Basolo and R.G. Pearson, Mechanisms of Inorganic Reactions, A Study of Metal Complexes in Solution (Wiley, NewYork, 1968).Google Scholar
  4. 4.
    K. Wieghardt, K. Phol, I. Jibril, and G. Huttner, Angew. Chem. Int. Ed. Engl. 23, 77 (1984).Google Scholar
  5. 5.
    S.M. Gorun and S.J. Lippard, Nature 319, 666 (1986).Google Scholar
  6. 6.
    S.J. Lippard, Chem. Br., 222 (1986).Google Scholar
  7. 7.
    W.H. Armstrong, M.E. Roth, and S.J. Lippard, J. Am. Chem. Soc. 109, 6318 (1987).Google Scholar
  8. 8.
    F. Mizukami, Y. Kobayashi, S. Niwa, M. Toba, and K. Shimizu, J. Chem. Soc. Chem. Commun., 1540 (1988).Google Scholar
  9. 9.
    F. Mizukami, M. Fujii, S. Niwa, and M. Toba, J. Sol-Gel Sci. Tech. 2, 359 (1994).Google Scholar
  10. 10.
    K. Kojima, F. Mizukami, M. Miyazaki, and K. Maeda, J. NonCryst. Solids 147&148, 442 (1992).Google Scholar
  11. 11.
    K. Maeda, F. Mizukami, S. Miyashita, S. Niwa, and M. Toba, J. Chem. Soc. Chem. Commun., 1268 (1990).Google Scholar
  12. 12.
    T. Nishide and F. Mizukami, Thin Solid Films 259, 212 (1995).Google Scholar

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© Kluwer Academic Publishers 1997

Authors and Affiliations

  • Kunihiko Kojima
  • Mitsuharu Miyazaki
  • Fujio Mizukami
  • Kazuyuki Maeda

There are no affiliations available

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