Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-23T23:21:29.007Z Has data issue: false hasContentIssue false
  • English
  • Français

Synchrotron X-ray microdiffraction (μXRD) in minerals and environmental research

Published online by Cambridge University Press:  17 November 2014

Markus Gräfe ,
Craig Klauber ,
Bee Gan  and
Ryan V. Tappero
Markus Gräfe*
Affiliation:
CSIRO Mineral Resources Flagship, 7 Conlon Street, Waterford, Western Australia 6152, Australia Universidad de las Américas, Facultad Ingeniería y Ciencias Agropecuarias, Centro de Investigación, Estudios y Desarrollo de Ingeniería (CIEDI), Quito – Ecuador
Craig Klauber
Affiliation:
CSIRO Mineral Resources Flagship, 7 Conlon Street, Waterford, Western Australia 6152, Australia
Bee Gan
Affiliation:
CSIRO Mineral Resources Flagship, 7 Conlon Street, Waterford, Western Australia 6152, Australia
Ryan V. Tappero
Affiliation:
Photon Sciences Department, Brookhaven National Laboratory, Upton, New York 11973
*
a)Author to whom correspondence should be addressed. Electronic mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

A number of synchrotron X-ray fluorescence microprobes (XFMs) around the world offer synchrotron X-ray microdiffraction (μXRD) to enhance mineral phase identification in geological and other environmental samples. Synchrotron μXRD can significantly enhance micro X-ray fluorescence and micro X-ray absorption fine structure measurements by providing direct structural information on the identity of minerals, their crystallinity, and potential impurities in crystal structures. The information is useful to understand the sequestration of metals in mineral deposits, mineral processing residues, soils, or sediments. Synchrotron μXRD was employed to characterize a surficial calcrete uranium (U) ore sample and to illustrate its usefulness in conjunction with U LIII μXANES analysis. μXRD and U LIII μXANES revealed that the mineral carnotite [K2(UO2)2(V2O8)·nH2O, n = 0, 1, 2, or 3] was not the sole U bearing mineral phase present and that surface complexes and or an amorphous precipitate were present as well. Unit-cell analysis from the μXRD patterns revealed that the interlayer spacing of carnotite was not uniform and that significant unit-cell volume expansions occurred likely because of variable cations (K+, Rb+, and Sr2+) and variably hydrated interlayer cations being present in the interlayer. Oriented specimen, single crystal effects, and the fixed orientation of the sample relative to the incident beam and the charge-coupled device camera limit the number of visible reflections and complicate mineral phase identification. With careful analysis of multiple structural analysis tools available at XFMs, however, a strong link between X-ray amorphous and X-ray crystalline materials in geologic and environmental samples can be established.

Keywords

X-ray fluorescence microscopysynchrotron X-raysmineralogytransmission geometrycarnotiteμXRDμXANES
Type
Technical Articles
Information
Powder Diffraction , Volume 29 , Issue S1 , December 2014 , pp. S64 - S72
Check for updates
Copyright
Copyright © International Centre for Diffraction Data 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ablett, J. M., Kao, C. C., Reeder, R. J., Tang, Y., and Lanzirotti, A. (2006). “X27A – A new hard X-ray micro-spectroscopy facility at the National Synchrotron Light Source,” Nucl. Instrum. Method Phys. Res. A 562, 487–494.CrossRefGoogle Scholar
Abraham, F., Dion, C., and Saadi, M. (1993). “Carnotite analogues: synthesis, structure and properties of the Na1−x-KxUO2VO4 solid solution (0 ≤ x ≤ 1),” J. Mater. Chem. 3, 459–463.CrossRefGoogle Scholar
Appleman, D. E. and Evans, H. T. Jr (1965). “The crystal structures of synthetic anhydrous carnotite, K2-(UO2)2V2O8, and its cesium analog, Cs2(UO2)2V2O8,” Am. Mineral. 50, 825–842.Google Scholar
Brinza, L., Schofield, P. F., Hodson, M. E., Weller, S., Ignatyev, K., Geraki, K., Quinn, P. D., and Mosselmans, J. F. W. (2014). “Combining microXANES and microXRD mapping to analyse the heterogeneity in calcium carbonate granules excreted by the earthworm Lumbricus terrestris,” J. Synchroton. Radiat. 21, 235–241.CrossRefGoogle Scholar
Bruker (2008). TOPAS. Version 4.2 (Computer Software) Bruker AXS, Karlsruhe, Germany.Google Scholar
Den Auwer, C., Simoni, E., Conradson, S., and Madic, C. (2003). “Investigating actinyl oxo cations by X-ray absorption spectroscopy,” Eur. J. Inorg. Chem. 21, 3843–3859.CrossRefGoogle Scholar
Galloway, C. M., Le Ru, E. C., and Etchegoin, P. G. (2009). “An iterative algorithm for background removal in spectroscopy by wavelet transforms,” Appl. Spectrosc. 63, 1370–1376.CrossRefGoogle ScholarPubMed
Gräfe, M., Landers, M., Tappero, R., Austin, P., Gan, B., Grabsch, A., and Klauber, C. (2011). “Combined application of QEM-SEM and hard X-ray microscopy to determine mineralogical associations and chemical speciation of trace metals,” J. Environ. Qual. 40, 767–783.CrossRefGoogle ScholarPubMed
Hammersley, A. P. (1987–2005). FIT2D. Grenoble, European Synchrotron Radiation Facility.Google Scholar
Ilavsky, J. (2012). “Nika: software for two-dimensional data reduction,” J. Appl. Crystallogr. 45, 324–328.CrossRefGoogle Scholar
Kolitsch, U. and Giester, G. (2001). “Revision of the crystal structure of ulrichite, CaCu2+(UO2)(PO4)2·4H2O,” Mineral. Mag. 65, 717–724.CrossRefGoogle Scholar
Templeton, D. H. and Templeton, L. K. (1982). “X-ray dichroism and polarized analomous scattering of the uranyl ion,” Acta Crystallogr. A 38, 62–67.CrossRefGoogle Scholar