Chemistry Reference
In-Depth Information
Chapter 3
Application of Mössbauer Spectroscopy
in Earth Sciences
Robert E. Vandenberghe and Eddy De Grave
Abstract Iron being the fourth most abundant element in the earth crust,
57
Fe
Mössbauer spectroscopy has become a suitable additional technique for the
characterization of all kind of soil materials and minerals. However, for that
purpose a good knowledge of the spectral behavior of the various minerals is
indispensable. In this chapter a review of the most important soil materials and
rock-forming minerals is presented. It starts with a description of the Mössbauer
spectroscopic features of the iron oxides and hydroxides, which are essentially
present in soils and sediments. Further, the Mössbauer spectra from sulfides,
sulfates and carbonates are briefly considered. Finally, the Mössbauer features of
the typical and most common silicate and phosphate minerals are reported. The
chapter ends with some typical examples, illustrating the use and power of
Mössbauer spectroscopy in the characterization of minerals.
3.1 Introduction
The discovery of the resonant absorption of gamma-rays in
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Ir by Rudolf
Mössbauer in 1958 was a milestone in nuclear physics because it was formerly
assumed that such a phenomenon could never occur due to the large recoil
energies involved. The interest for this new finding was nevertheless still limited in
the first years, but, a real breakthrough emerged from the fact that many isotopes
showed a larger and much more sensitive effect. So, a new technique, called
Mössbauer spectroscopy, was born. The most important feature of this spectro-
scopic method is the extreme sharpness of the emission line which can easily be
R. E. Vandenberghe (
)
E. De Grave
Department of Physics and Astronomy, Ghent University,
Proeftuinstraat 86, 9000 Ghent, Belgium
&
