The transformation of mackinawite into greigite studied by Raman spectroscopy
Version of Record online: 24 JUN 2010
Copyright © 2010 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Volume 42, Issue 3, pages 496–504, March 2011
How to Cite
Bourdoiseau, J.-A., Jeannin, M., Rémazeilles, C., Sabot, R. and Refait, P. (2011), The transformation of mackinawite into greigite studied by Raman spectroscopy. J. Raman Spectrosc., 42: 496–504. doi: 10.1002/jrs.2729
- Issue online: 20 MAR 2011
- Version of Record online: 24 JUN 2010
- Manuscript Accepted: 20 MAY 2010
- Manuscript Received: 2 APR 2010
- French national radioactive waste management agency
- solid-state transformation;
- localized corrosion
In this study, Raman spectroscopy was used to precisely understand the mechanisms of oxidation of mackinawite (FeS). Two experimental conditions were considered: (1) oxidation in air at room temperature and (2) oxidation in acidic anoxic solutions at 80 °C. In both cases, the oxidation process began by the in situ oxidation of Fe(II) cations inside the crystal structure of mackinawite and led to Fe(III)-containing mackinawite, FeII1−3xFeIII2xS. The oxidation in air finally led to Fe(III) oxyhydroxides and elemental sulfur α-S8, but greigite (Fe3S4) was observed as an intermediate compound. In anoxic acidic solutions, the product of the oxidation was proved to depend on the Fe/S concentration ratio. For Fe/S = 3/4, greigite was the only product obtained, and this allowed us to determine unambiguously the Raman spectrum of this compound. Copyright © 2010 John Wiley & Sons, Ltd.