Conversion Electron Mössbauer Spectroscopy

Abstract

Conversion electron Mossbauer spectrometry (CEMS) has been developed and widely used for surface study of solid materials, which contain iron (57Fe) and tin (119Sn). Table 1 shows the development of CEMS. At the initial stage, an electron energy analyzer was experimentally used to certificate the principle of CEMS, but the luminosity was very low. The electron energy analyzer was not useful for daily measurement of CEMS. CEMS, X-ray MS (XMS) and scattering y-ray MS (GMS) are effectively used in order to analyze the chemical states of surface layers with the thickness from several tens of nm to several tens of mm non-destructively. Integral CEMS (ICEMS) has been most widespread since a simple gas flow counter was developed. Low temperature CEMS, Auger electron MS (AEMS) and glancing angle CEMS (GACEMS) have been developed recently. Depth selective CEMS (DCEMS) has been again used to analyze thin films with more precise depth although enriched 57Fe is often used. Some reviews concerning CEMS have been published in the various fields [43]. The surface of solid improved by ion implantation has been most often analyzed by CEMS [44] because the ion implanted layer can be easily controlled to the observed layer. There are relatively not so many chemical applications of CEMS. The development of CEMS and the analytical applications to (i) corrosion layers, (ii) chemical coatings of steel, (iii) oxide films prepared by spray pyrolysis, (iv) transparent conductive films and (v) diffused tin in the bottom surface of glass are presented in this article. The advantage and feasibility of CEMS are hereby discussed from the viewpoint of the chemical applications.