Low-temperature field evaporation mass spectrometry of Fe, Co and Ni

Abstract

Mass spectrometric analysis of the products of low-temperature field evaporation is a new and important technique through which surface phenomena can be investigated. A short review of the existing theories of field evaporation is presented to provide the uninitiated reader with some physical insight into the nature of this phenomenon and the type of information to be learned from an investigation of it. A simple field evaporation mass spectrometer has been used to analyse some of the field evaporation products of Fe, Co and Ni. The additional products formed when these three metals are field evaporated in the presence of N 2, O 2 and CO are also investigated. The difficulties in recording and detecting such field evaporation mass spectra are presented. The limitations of the existing apparatus and experimental technique are pointed out, and some directions for possible improvements in both of these areas are indicated. The nature of the field evaporation spectra which result is discussed, and the information content of these spectra is analysed.