Mikrochim. Acta [Wien] 1987, I, 125--134 Mikrochimica Acta 9 by Springer-Verlag 1987 Application of EELS to the Microanalysis of Materials Ferdinand Hofer* and Peter Warbichler Forschungsinstitut fur Elektronenmikroskopie und Feinstrukturforschung, Technische Universit/~t Graz, Steyrergasse 17, A-8010 Graz, Austria Abstract. Electron energy loss spectroscopy (EELS) is used in analytical electron microscopy (AEM) because it can provide results on the chemical composition and structure of a small volume of material. The practical application of EELS was demonstrated by the investigation of a refractory hard metal of the type WC-TiC-Co and by the investigation of a BaTiO3 ceramic material. To demonstrate the present status of quantitative analysis by EELS, the spectra of BezSiO4, TiB2 and BaTiO3 were quantified and the results indicate that quantitative analysis is feasible for major concentrations of light elements and also of heavier elements even in the presence of severe edge overlap. Key words: electron energy-loss spectroscopy, analytical electron microscopy, microanalysis. For the last years electron energy-loss spectroscopy (EELS) has been described as a promising tool for the study of the local composition of solid samples [1--3]. In the beginning of EELS it was mainly considered to be a supple- menting tool within the analytical electron microscope when compared to energy-dispersive X-ray spectrometry (EDX), but EELS has become a method which can give by far more information on the nature of solids than EDX: EELS is capable of analyzing all elements from lithium to uranium and is especially suited to detect the ultralight elements due to the high signal collection efficiency which is ca. 50 times higher than for X-rays [4]. Furthermore, one can extract from the fine structures of the ionization edges, oxidation states [5], bond distances [6] and, under favourable circum- stances, the electronic structure of solids [7]. All this can be achieved by using transmission electron microscopes fitted with an appropriate electron spectrometer. * To whom correspondence should be addressed