Determination of the mean absorption potential of Si for electrons by energy loss spectroscopy

Complex structure potentials of silicon for 111 systematic diffraction were measured by convergent beam electron diffraction technique (Kossel - Molle nstedt pattern). The imaginary mean potential and its different components were determined directly by measuring the energy loss spectra of transmitte d electrons by means of an imaging filter (GIF) installed in the electron m icroscope. The imaginary mean inner potential was estimated to be 0.63 eV. The component of the imaginary inner potential due to plasmon excitation wa s estimated to be 0.53 eV. Some low indexed Fourier components were determi ned by matching intensity simulations to Kossel-Mollenstedt patterns. The a bsorption potential due to thermal vibration was found to be in the order o f the full Einstein model.