MOESSBAUER SPECTROSCOPY IN MINERALOGY AND GEOLOGY

摘要

A great advantage of Mossbauer spectroscopy (MS) compared to macroscopic classical techniques lies in the possibility of separating, in a very simple way, magnetic and nonmagnetic sublattices. This may be the case of ions at non-equivalent crystallographic sites, ions in different charge states (for example Fe~(2+)/Fe~(3+), fluctuating valences, etc.) or magnetically different ions. Typical materials in that respect are magnetic oxides and magnetic fraction of minerals, intermetalic compounds and other materials interesting from a fundamental as well as a technological point of view. In the physics of minerals, Moessbauer spectroscopy gives some insight into electronic structure of inhomogenous mixed-valent compounds. Through the determination of hyperfine parameters, different iron-bearing components and also different types of iron present in a mineral can be distinguished in the sample. This leads to variety of applications in geological and mineralogical branches such as paleomagnetism, meteorites, earth science, extraterrestrial samples, etc.