Free Access
Microsc. Microanal. Microstruct.
Volume 2, Number 5, October 1991
Page(s) 561 - 568
Microsc. Microanal. Microstruct. 2, 561-568 (1991)
DOI: 10.1051/mmm:0199100205056100

A study of silicon ELNES in nesosilicates

David W. McComb1, Poul L. Hansen2 et Rik Brydson3

1  Microstructural Physics Group, Cavendish Laboratory, Madingley Rd., Cambridge CB3 OHE, G.B.
2  Laboratory of Applied Physics, Technical University of Denmark, 2800 Lyngby, Denmark
3  The Blackett Laboratory, Imperial College, Prince Consort Rd., London SW7 2B2, G.B.

Si L2,3-absorption edges have been collected using EELS from four nesosilicates; Forsterite, Fayalite, Phenacite and Willemite. Nesosilicates, also known as orthosilicates or island silicates, are the simplest materials to be found in the silicate mineral class, consisting of isolated tetrahedral SiO4 groups. While many features in energy-loss spectra are common to all of the materials, remarkable extra intensity was observed for Forsterite. This appears to arise from distortion of the SiO4 tetrahedron; a hypothesis supported by XANES calculations. The concept of a simple fingerprint in near-edge structure analysis is questioned.

7920U - Electron energy loss spectroscopy.
8280P - Electron spectroscopy (x-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.).
9165 - Geophysical aspects of geology, mineralogy, and petrology.

Key words
EEL spectroscopy -- Inner-shell excitation -- MO method -- XANES -- Energy-level transitions -- Ternary compounds -- Iron silicates -- Magnesium silicates -- Beryllium silicates -- Zinc silicates -- Forsterite -- Mg2SiO4 -- Fe2SiO4 -- Be2SiO4 -- Zn2SiO4

© EDP Sciences 1991