J. Phys. IV France
Volume 104, March 2003
Page(s) 373 - 376

J. Phys. IV France
104 (2003) 373
DOI: 10.1051/jp4:20030102

XPEEM valence state imaging of mineral micro-intergrowths with a spatial resolution of 100 nm

A.D. Smith1, P.F. Schofield2, A. Scholl3, R.A.D. Pattrick4 and J.C. Bridges1

1  CLRC-Daresbury Laboratoly, Warrington, Cheshire WA4 4AD, U.K.
2  Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD, U.K.
3  Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, U.S.A.
4  Department of Earth Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.

The crystal chemistry and textural relationships of minerals hold a vast amount of information relating to the formation, history and stability of natural materials. The application of soft X-ray spectroscopy to mineralogical material has revealed that 2p (L 2,3) spectra provide a sensitive fingerprint of the electronic states of 3d metals. In bulk powdered samples much of the textural and microstructural information is lost, but the area-selectivity capability of X-ray Photo-Emission Electron Microscopy (XPEEM) provides the ability to obtain valence state information from mineral intergrowths with a submicron spatial resolution.

Using the state-of-the-art PEEM2 facility on beamline at the Advanced Light Source, Berkeley, USA, a range of minerals, mineral intergrowths and mineralogical textures have been studied for a broad suite of geological, planetary and environmental science materials. High-quality, multi-element valence images have been obtained showing the distribution/variation of the metal valence states across single grains or mineral intergrowths/textures at the l00 nm scale and quantitative valence state ratios can be obtained from areas of ~0.01  $\rm\mu m^2$.

© EDP Sciences 2003