Hyperfine Interactions

, Volume 148, Issue 1–4, pp 153–161

Thermally Induced Magnetite–Haematite Transformation

  • J. Mazo-Zuluaga
  • C. A. Barrero
  • J. Díaz-Terán
  • A. Jerez
Article

Abstract

The products of thermal treatments of pure and copper doped magnetites have been investigated using Mössbauer spectrometry, XRD and thermal analysis techniques. The samples were heated in air between RT and 800°C at several heating rates. Samples treated at 520°C during 12 and 24 hours consist only of well-crystallized haematite. On the other hand, magnetites treated at 350°C consisted of mixtures of haematite, maghemite and magnetite, with relative amount of each phase depending on the presence of copper as well as on the heating time. Results show that the transformation of magnetite to haematite goes through the formation of maghemite, and that the presence of copper delays this transformation.

Mössbauer spectroscopy magnetite maghemite haematite 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Cornell, R. M. and Schwertmann, U., In: The Iron Oxides, VCH mbH, Weinheim, Germany, 1996.Google Scholar
  2. 2.
    Nasrazadani, S. and Raman, A., Corros. Sci. 34 (1993), 1355.CrossRefGoogle Scholar
  3. 3.
    Schwertmann, U. and Cornell, R. M., In: Iron Oxides in the Laboratory, 1st edn, VCH mbH, Weinheim, Germany, 1991.Google Scholar
  4. 4.
    Barrero, C. A., Morales, A. L., Mazo-Zuluaga, J., Jaramillo, F., Pérez, G., Escobar, D. M., Arroyave, C. E., Tobón, J., Montoya, P. M., Osorio, L. F., Vandenberghe, R. E. and Greneche, J. M., Hyp. Interact. 134 (2001), 141.CrossRefGoogle Scholar
  5. 5.
    Vandenberghe, R. E., De Grave, E. and de Bakker, P. M. A., Hyp. Interact. 83 (1994), 29.CrossRefGoogle Scholar
  6. 6.
    da Costa, G. M., De Grave, E., de Bakker, P. M. A. and Vandenberghe, R. E., Clay & Clays Miner. 43 (1995), 656.Google Scholar
  7. 7.
    Sidhu, P. S., Gilkes, R. J. and Posner, A. M., J. Inorg. Nucl. Chem. 40 (1978), 429.CrossRefGoogle Scholar

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • J. Mazo-Zuluaga
    • 1
  • C. A. Barrero
    • 1
  • J. Díaz-Terán
    • 2
  • A. Jerez
    • 2
  1. 1.Grupo de Estado Sólido, Instituto de FísicaUniversidad de AntioquiaMedellínColombia
  2. 2.Departamento de Química Inorgánica y Química TécnicaUniversidad Nacional de Educación a Distancia UNED, P○ Senda del Rey 9MadridEspaña

Personalised recommendations