Transmission Mössbauer Spectroscopic Studies of Fe-containing materials
EMSL Project ID
49489
Abstract
Fe is ubiquitous in soils and sediments, and its redox chemistry plays an important role in the fate and transport of nutrients, migration/attenuation of hazardous compounds, and dynamics of soil organic matter in rhizosphere and vadose zones. Fe(II)/(III)-oxides, Fe(II)/Fe(III)-containing silicates, particularly phyllosilicates, and Fe-sulfides, are some of the common Fe-minerals in subsurface. The role of these minerals in soils and sediments, particularly in Fe-poor soils containing numerous Fe-phases, however, is not straightforward. This is due to the profound effects of particle-size/crystallinity, metal substitutions, and coatings on surface composition. Information from NMR, XRD, XPS, and Fe-XAS methods, often, is inadequate to address the underlying mechanisms. 57Fe-transmission Mössbauer spectroscopy (TMS), a bulk and Fe-specific technique, that provides information on oxidation state, spin state, bonding properties such covalency and electronegativity, site symmetry, and magnetic properties, is an another (or preferred) spectroscopic tool commonly employed to provide additional, complementary information on Fe mineralogy of soils/sediments. Interpretation/modeling of Mössbauer spectroscopy data in the complex systems, however, is not straightforward primarily due to lack of theoretical parameters of many compounds, and to a certain extent absence of “standard” sample data. In this study, to address these issues, mainly to generate “standard” spectral data, samples from various projects will be used to compile a library of Mössbauer data that would be relevant to DOE-OBER research.
Project Details
Start Date
2016-05-02
End Date
2018-09-30
Status
Closed
Released Data Link
Team
Principal Investigator