Absorption coefficients of electrons in crystals

Absorption coefficients of Si, Ge and InSb are obtained from the analysis of extinction contours in the acceleration voltages ranging from 100 to 750 kV. The cross sections of thermal diffuse scattering, plasmon excitation and electronic excitation are obtained separately. An agreement between theory and experiment is obtained for thermal diffuse scattering and plasmon scattering. The theoretical estimation based on the electron gas statistical model is favourable for the electronic excitation. (Auth.)