Electron-Spectrometric Study of Amorphous Germanium and Silicon in the Two-Phonon Region

Abstract
The energy-loss spectra of 25-keV electrons transmitted through thin amorphous Ge and Si films have been measured in the range of very small energy losses between 25 and 400 meV. The resolution was 4 and 6 meV. The main intensity in the spectra is located at low energy and is caused by "defect-induced" two phonon excitation.