Advanced EELS techniques in the TEM
This chapter reviews some of the more specialized techniques that can be performed in the environment of the Transmission Electron Microscopy (TEM) which are of particular relevance for materials science and solid state physics. A volume plasmon often shows a characteristic parabolic free-electron shape for the dispersion curve; however when the momentum transfer exceeds a certain value this collective oscillation cannot exist and decays into single electron excitations. The quantification of segregation levels at microstructural features such as interfaces and defects is becoming an increasingly important topic in materials characterization owing to the fact that trace amounts of impurities or dopants can, in many cases, modify microstructural development and affect the final mechanical, electrical or thermal properties of the macroscopic material. The energy position of the Compton peak depends on the square of the scattering angle and would be a delta function if the scattering were from stationary free electrons.