EXAFS Signatures of Structural Zn at Trace Levels in Layered Minerals

Farid Juillot (1) , Guillaume Morin (1) , Jean-Louis Hazemann (2) , Olivier Proux (2) , Stephanie Belin (3) , Valerie Briois (3) , Gordon E. Brown , Georges Calas (1)

1 IPGP - Institut de Physique du Globe de Paris
2 ESRF - European Synchrotron Radiation Facility
3 SSOLEIL - Synchrotron SOLEIL

Many in situ XAFS studies have shown that zinc incorporated in layered minerals is a major form of zinc in Zn-contaminated soils. Quantitative information on the local structural environment(s) and ordering of Zn in these minerals is required to better understand its behavior in soils. In this study, EXAFS spectroscopy was used to assess the structural environment of zinc incorporated at trace levels (40 ppm to 4,000 ppm) within the octahedral sheets of various natural and synthetic layered minerals. Results indicate that EXAFS data analyzed using ab initio FEFF calculations (FEFF 8.10) can unambiguously distinguish between zinc incorporation within the octahedral sheet of dioctahedral versus trioctahedral layered minerals and can determine the distribution (random or ordered) of zinc cations within the octahedral sheets of these minerals.

Mots clés: 61.10.Ht; 91.65.An; 91.62.Rt; X-ray absorption spectroscopy: EXAFS NEXAFS XANES etc.; Mineral and crystal chemistry; Land pollution soil pollution

Domaines: Planète et Univers [physics]

Farid Juillot, Guillaume Morin, Jean-Louis Hazemann, Olivier Proux, Stephanie Belin, et al.. EXAFS Signatures of Structural Zn at Trace Levels in Layered Minerals. X-Ray Absorption Fine Structure - XAFS13: 13th International Conference. Proceedings held at Stanford, 2007, à renseigner, Unknown Region. pp.247-249, ⟨10.1063/1.2644490⟩. ⟨insu-03603199⟩