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Iron(III) Oxides Formed During Thermal Conversion of Rhombohedral Iron(III) Sulfate

  • R. Zboril
  • M. Mashlan
  • L. Machala
  • P. Bezdicka
Part of the NATO Science Series book series (NAII, volume 94)

Abstract

The mechanism of thermal decomposition of rhombohedral iron(III) sulfate in air depends significantly on the conditions for diffusion of SO3 (temperature, thickness of the powdered layer, particle size). The influence of particle size on the reaction mechanism was studied at 600 °C using 57Fe Mössbauer spectroscopy and XRD. Corundum-type α-Fe2O3, bixbyite-type β-Fe2O3, and orthorhombic ε-Fe2O3 were identified as solid conversion products. Time dependence of the relative contents of individual polymorphs (x-Fe2O3/ΣFe2O3) is a suitable means for monitoring the mechanism of their formation and thermal transformation during the reaction process. The quantitative Mössbauer data obtained from the corresponding spectral areas demonstrate that different transformations occur in the surface layer and in the bulk of sulfate particles. Particles of β-Fe2O3 formed after loosening of SO3 from the surface layer of sulfate particles are relatively stable at 600 °C as documented by the very slow structural change to hematite. The formation of complicated ε-Fe2O3 structure is probably related with the slow diffusion of SO3 from the bulk of sulfate particles. The isochemical transformation of ε-Fe2O3 to hematite occurs more quickly due to its lower thermal stability in comparison with β-Fe2O3.

Keywords

Mossbauer Spectroscopy Ferric Sulfate Sulfate Particle Mossbauer Spectrum Maghemite Nanoparticles 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Cornel, R.M., and Schwertmann, U. (1996) The Iron Oxides. Structure, Properties, Reactions and Uses, VCH, Weinheim.Google Scholar
  2. 2.
    Mitra, S., (1992) Applied Mössbauer Spectroscopy, Series: Physics and Chemistry of the Earth, Vol. 18, Pergamon, OxfordGoogle Scholar
  3. 3.
    Catlow, C.R., Corish, J., Hennesy, J., and Mackrodt, W.C. (1988) Atomistic simulation of deffect structures and ion-transport in alpha-Fe2O3 and alpha Cr2O3, J. Am. Ceram. Soc. 71, 42–49.CrossRefGoogle Scholar
  4. 4.
    Bowen, L.H., De Grave, E, and Vandenberghe, R.E. (1993) Mössbauer effect studies of magnetic soils and sediments, in G. J. Long, and F. Grandjean (eds.), Mössbauer Spectroscopy Applied to Magnetism and Materials Science, Vol.1, Plenum Press, New York, pp. 132–141.Google Scholar
  5. 5.
    Fysh, S.A., and Clark, P.E. (1982) Aluminous hematite — a Mössbauer study. Phys. Chem. Miner. 8, 257–267.ADSCrossRefGoogle Scholar
  6. 6.
    Vandenberghe, R.E., de Grave, E., Landuydt, C., and Bowen, L.H. (1990) Some aspects concerning the characterization of iron oxides and hydroxides in soils and clays, Hyperfine Interact. 53, 175–193.ADSCrossRefGoogle Scholar
  7. 7.
    Murad, E., and Schwertmann, U. (1986) Influence of Al substitution and crystal size on the room-temperature Mössbauer spectrum of hematite, Clay. Clay Miner. 34, 1–6.ADSCrossRefGoogle Scholar
  8. 8.
    Rancourt, D.G., Julian, S.R., and Daniels, J.M. (1985) Mössbauer characterization of very small superparamagnetic particles — application to intra-zeolitic alpha Fe2O3 particles, J. Magn. Magn. Mater. 49,305–316.ADSCrossRefGoogle Scholar
  9. 9.
    Dormann, J.L., Cui, J.R., and Sella, C (1985) Mössbauer studies of Fe2O5 antiferromagnetic small particles, J. Appl. Phys., 57, 4283–4285.ADSCrossRefGoogle Scholar
  10. 10.
    Bødker, F., Hansen, M.F., Koch, C.B., Lefmann, K., and Mørup S. (2000) Magnetic properties of hematite nanoparticles, Phys. Rev. B 61, 6826–6838.ADSCrossRefGoogle Scholar
  11. 11.
    Rancourt, D.G., and Daniels, J.M. (1984) Influence of unequal magnetization direction probabilities on the Mössbauer spectra of superparamagnetic particles, Phys. Rev. B 29, 2410–2414.ADSCrossRefGoogle Scholar
  12. 12.
    Jing, J., Zhao, F., Yang, X., and Gonser, U. (1990) Magnetic relaxation in nanocrystalline iron oxides, Hyperfine Interact. 54, 571–575.ADSCrossRefGoogle Scholar
  13. 13.
    Ikeda, Y., Takano, M., and Bando, Y. (1986) Formation of needle-like alpha-iron(III) oxide particles grown along the c-axis and characterization of precursorily formed beta-iron(III) oxide, Bull. Inst. Chem. Res., Kyoto Univ. 64, 249–258.Google Scholar
  14. 14.
    Ben-Dor, L., Fischbein, E., Feiner, I., and Kaiman, Z. (1977) β Fe2O3: Preparation of thin films by chemical vapor deposition from organometallic chelates and their characterization. J. Electrochem. Soc. 124, 451–457.CrossRefGoogle Scholar
  15. 15.
    Muruyama, T., and Kanagawa, T. (1996) Electrochromic properties of iron oxide thin films prepared by chemical vapor deposition, J Electrochem. Soc. 143, 1675–1677.CrossRefGoogle Scholar
  16. 16.
    Gonzales-Carreno, T., Morales, M.P., and Serna, C.J. (1994) Fine beta-Fe2O3 particleswith cubic structure obtained by spray pyrolysis, J. Mater. Sci. Lett. 13, 381–382.CrossRefGoogle Scholar
  17. 17.
    Bauminger, E.R., Ben-Dor, L., Feiner, I., Fischbein, E., Nowik, I., and Ofer, S. (1977) Mössbauer effect studies of β Fe2O3, Physica B 86-88, 910–912.CrossRefGoogle Scholar
  18. 18.
    Ben-Dor, L., and Fischbein, E. (1976) Concerning the β phase of iron(III) oxide. Acta Cryst. B 32, 667.CrossRefGoogle Scholar
  19. 19.
    Wiarda, D., Wenzel, T., Uhrmacher, M., and Lieb, K.P. (1992) Hyperfine interaction of 111Cd impurities in Mn2O3Mn3O4 and β-Fe2O3, J. Phys. Chem. Solids 53, 1199–1209.ADSCrossRefGoogle Scholar
  20. 20.
    Wiarda, D., and Weyer, G. (1993) Mössbauer investigations of the antiferromagnetic phase in the metastable beta-ferric oxide, Int. J. Mod. Phys. B 7, 353–356.ADSCrossRefGoogle Scholar
  21. 21.
    Pascal, C., Pascal, J.L., Favier, F., Elidrissi Moubtassim, M.L., and Payen, C. (1999) Electrochemical synthesis for the control of γ-Fe2O3 nanoparticle size. Morphology, microstructure, and magnetic behavior, Chem. Mater. 11, 141–147.CrossRefGoogle Scholar
  22. 22.
    Ennas, G., Musinu, A., Piccaluga, G., Zedda, D., Gatteschi, D., Sangregorio, C., Stanger, J.L., Concas, G., and Spano, G. (1998) Characterization of iron oxide nanoparticles in an Fe2O3-SiO2 composite prepared by a sol-gel method, Chem. Mater. 10, 495–502.CrossRefGoogle Scholar
  23. 23.
    Cannas, C., Gatteschi, D., Musinu, A., Piccaluga, G., and C. Sangregorio (1998) Structural and magnetic properties of Fe2O3 nanoparticles dispersed over a silica matrix, J. Phys. Chem. B 102, 7721–7726.CrossRefGoogle Scholar
  24. 24.
    Serna, C.J., Bø;dker, F., Mørup, S., Morales, M.P., Sandiumenge, F., and Verdaguer S. (2001) Spin frustration in maghemite nanoparticles, Solid State Commun. 118, 437–440.ADSCrossRefGoogle Scholar
  25. 25.
    Martinez, B., Roig, A., Obradors, X., Mollins, E., Rouanet. A., and Monty, C. (1996) Magnetic properties of γ-Fe2O3 nanoparticles obtained by vaporization condensation in a solar furnace, J. Appl. Phys. 79, 2580–2586.ADSCrossRefGoogle Scholar
  26. 26.
    Tronc, E., Chanéac, C., and Jolivet, J.P. (1998) Structural and magnetic characterization of ε-Fe2O3, Solid State Chem. 139, 93–104.ADSCrossRefGoogle Scholar
  27. 27.
    Schrader, R., and Büttner. G. (1963) Eine neue Eisen(III)-oxidphase: ε-Fe2O3, Z. Anorg. Allg. Chem. 320, 220–234.CrossRefGoogle Scholar
  28. 28.
    Dézsi, I, and Coey, J.M.D. (1973) Magnetic and thermal properties of ε-Fe2O3, Phys. Status. Solidi A 15, 681–685.ADSCrossRefGoogle Scholar
  29. 29.
    Dormann, J. L., Viart, N., Rehspringer, J. L., Ezzir, A., and Niznansky, D. (1998): Magnetic properties of Fe2O3 particles prepared by sol-gel method, Hyperfine Interact. 112, 89–92.ADSCrossRefGoogle Scholar
  30. 30.
    Zboril, R, Mashlan, M., Krausova, D., and Pikal, P. (1999) Cubic β-Fe2O, as the product of thermal decomposition of Fe2(SO4)3, Hyperfine Interact. 121-122, 497–501.ADSCrossRefGoogle Scholar
  31. 31.
    Zboril, R., Mashlan, M., and Petridis, D. (2002) Iron(III) Oxides from Thermal Processes-Synthesis, Structural and Magnetic Properties, Mössbauer Spectroscopy Characterization, and Applications, Chem. Mater. 14, 969–982.CrossRefGoogle Scholar
  32. 32.
    Zboril, R., Mashlan, M., Krausova, D. (1999) The mechanism of β-Fe2O3 formation by the solid state reaction between NaCl and Fc2(SO4)3, in M. Miglierini and D. Petridis (eds.), Mössbauer Spectroscopy in Materials Science, Kluwer Academic Publishers, Dordrecht, pp. 49–56.CrossRefGoogle Scholar
  33. 33.
    Barcova, K., Mashlan, M, Zboril, R., Martinec, P., and Kula, P. (2001) Thermal decomposition of almandine garnet: Mössbauer study, Czech. J. Phys. 51, 749–754.ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2003

Authors and Affiliations

  • R. Zboril
    • 1
  • M. Mashlan
    • 1
  • L. Machala
    • 1
  • P. Bezdicka
    • 2
  1. 1.Departments of Inorganic and Physical Chemistry, and Experimental PhysicsPalacky UniversityCzech Republic
  2. 2.Institute of Inorganic ChemistryAcademy of SciencesCzech Republic

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