Characteristic Energy Losses of Electrons in Solids

Abstract

Publisher Summary This chapter provides an overview of the wealth of information acquired on the characteristic energy losses of electrons and describes the methods and instruments used in the measurements, which show that the observed characteristic energy losses are, in first approximation at least, independent of the methods and instruments used in their observation. It is shown that the instrumentation used in measurements done in recent times use the Mollenstedt method. Where photographic plates have been used for detection, there would be some doubt as to the accuracy of intensity and width measurements even though attempts were made to calibrate the photographic plates. In this respect the early measurements of Rudberg, Haworth, and Farnsworth using Faraday cage and electrometer and the recent work of Marton and Leder using photomultiplier should be more dependable. The use of the electron microscope allows easy inspection of the specimen through observation of its image projected by the objective lens on to a fluorescent screen in the slit plane. This inspection is very useful, because thin film specimens frequently burst or curl up under the action of the intense primary beam, and from a practical viewpoint it is a great advantage to be able to discard a damaged specimen or to select an undamaged area. This chapter also reviews experimental data, qualitative interpretation, and theoretical problems related to the observations.