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Clays and Clay Minerals

, Volume 43, Issue 5, pp 599–606 | Cite as

Iron Substitution in Soil and Synthetic Anatase

  • U. Schwertmann
  • J. Friedl
  • G. Pfab
  • A. U. Gehring
Article

Abstract

IronIII for TiIV substitution in the structure of pedogenic and synthetic anatase of up to Fe/ (Ti+Fe) 0.1 mol/mol was indicated by an increase in unit cell size as measured by XRD line shifts. Mössbauer- and electron paramagnetic resonance spectra at both, 298 K and 4.2 K supported this by the presence of signals typical for octahedrally coordinated FeIII in a diamagnetic matrix. Charge compensation was achieved by structural OH, as indicated by FTIR bands at 3360 and 960 cm−1, which were absent in pure anatase and which disappeared on heating. The weight loss on heating amounted to ca. 0.5 mol H2O/mol Fe. At 600°C structural Fe was ejected, the unit cell size decreased to that of pure anatase, and pseudobrookite, Fe2TiO5, was formed.

Key Words

Anatase Crystal chemistry EPR Fe substitution FTIR Mössbauer OH-O-substitution Pseudobrookite TA TEM XRD 

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Copyright information

© The Clay Minerals Society 1995

Authors and Affiliations

  • U. Schwertmann
    • 1
  • J. Friedl
    • 1
  • G. Pfab
    • 1
  • A. U. Gehring
    • 1
  1. 1.Lehrstuhl für BodenkundeTechnische Universität MünchenFreising-WeihenstephanGermany

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