ELECTRON ENERGY-LOSS SPECTROSCOPY AND CHEMICAL-CHANGE

Electron energy loss spectroscopy provides a sensitive in situ method of studying beam-induced changes in the overall chemical composition of a thin specimen. Light-element concentrations can be monitored using the appropriate inner-shell ionization edges; free-electron metals can be identified from their plasmon-loss spectrum. Electron irradiation causes mass loss due to bond scission, radiolysis or surface sputtering, depending on the type of specimen. However, mass loss can often be reduced by cooling the specimen and/or the use of surface coatings.