Deciphering Ni sequestration in soil ferromanganese nodules by combining x-ray fluorescence, absorption and diffraction at micrometer scales of resolution

Journal Article · Wed Nov 06 04:00:00 EST 2002 · American Mineralogist

DOI:https://doi.org/10.2138/am-2002-1028· OSTI ID:807411

Manceau, Alain ^[1]; Tamura, Nobumichi; Marcus, Matthew A; MacDowell, Alastair A; Celestre, Richard S; Sublett, Robert E; Sposito, Garrison; Padmore, Howard A

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1. LBNL Library

X-ray microprobes are among the most important new analytical techniques to emerge from third generation synchrotron facilities. Here we show how X-ray fluorescence, diffraction, and absorption can be used in parallel to determine the structural form of trace elements in heterogeneous matrices at the micrometer-scale of resolution. Scanning X-ray microfluorescence (microSXRF) and microdiffraction (microSXRD) first are used to identify the host solid phase by mapping the distributions of elements and solid species, respectively. Micro-extended X-ray absorption fine structure (microEXAFS) spectroscopy is then used to determine the mechanism of trace element binding by the host phase at the molecular scale. To illustrate the complementary application of these three techniques, we studied how nickel is sequestered in soil ferromanganese nodules, an overwhelmingly complex natural matrix consisting of submicrometer to nanometer sized particles with varying structures and chemical composition s. We show that nickel substitutes for Mn3+ in the manganese layer of the MnO2-Al(OH)3 mixed-layer oxide lithiophorite. The affinity of Ni for lithiophorite was characteristic of micromodules sampled from soils across the U.S.A. and Europe. Since many natural and synthetic materials are heterogeneous at nanometer to micrometer scales, the synergistic use of microSXRF, microSXRD and microEXAFS is expected to have broad applications to earth and materials science.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director, Office of Science. Office of Basic Energy Studies; Environmental Protection Agency (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 807411
• Report Number(s): LBNL--50453; B& R KC0204016
• Journal Information: American Mineralogist, Journal Name: American Mineralogist Journal Issue: 10 Vol. 87; ISSN AMMIAY; ISSN 0003-004X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
54 ENVIRONMENTAL SCIENCES
ABSORPTION
CHEMICAL COMPOSITION
DIFFRACTION
FINE STRUCTURE
FLUORESCENCE
NICKEL
RESOLUTION
SOIL FERROMANGANESE NICKEL SEQUESTRATION ABSORPTION SPECTROSCOPY MICROFLUORESCENCE MICRODIFFRACTION
SOILS
SPECTROSCOPY
SYNTHETIC MATERIALS
TRACE AMOUNTS