Scanning Electron Microscopy


Core edges recorded in Electron Energy Loss Spectroscopy (EELS) display a large variety of profiles. We have investigated several specific aspects concerning Energy Loss Near Edge Structures (ELNES) and emphasize the interest in a careful edge shape analysis to obtain refined microanalytical information, such as local symmetry. After indicating the general impact of EELS fine structures as compared to EDX and Auger spectroscopies we discuss the instrumental conditions required for recording satisfactory spectra and consider the theoretical problems which are involved in data interpretation. The major portion of this paper presents results for selected K, L23, M45 and N45 core excitations in compounds (mainly oxides). In each case the phenomena governing the ELNES distribution are pointed out. In conclusion, we summarize the potential of a careful analysis of ELNES for studying the chemical state of the absorbing atom and the symmetry of it s first coordination shell (molecular description) or longer range effects (projections of solid state density of states as seen by the ejected atom).

Included in

Biology Commons