Electron energy-loss spectroscopy and the crystal chemistry of rhodizite. Part 1.—Instrumentation and chemical analysis

An electron microscope fitted with a magnetic prism spectrometer and a parallel recording system has been used to measure the electron energy-loss spectrum of rhodizite, a naturally occurring mineral containing a number of light elements which are difficult to detect with energy-dispersive X-ray emission analysis (X.r.e.). We consider in detail the use of electron energy-loss spectroscopy (EELS) as an analytical probe and the quantitative chemical analysis for beryllium, boron and aluminium, measured with respect to oxygen, is in good agreement with the analysis obtained using wet chemical and crystallographic methods. The presence of potassium and caesium is confirmed, but for these elements the quantitative analysis is less reliable. X.r.e. measurements are also given for comparison. The potential as well as the limitations associated with the use of parallel recording arrays for chemical analysis based on EELS, is discussed.