Interband scattering of channelled electrons suffering high energy losses

Abstract

An analysis has been made of the loss in fringe contrast, with increasing energy loss, observed in thickness fringes due to energy-filtered inelastically scattered electrons in a wedge foil of aluminium oriented to a (111) Bragg condition. The fringe amplitudes, observed in a transmission electron microscope equipped with an energy-loss spectrometer, result from intraband and interband scattering between dispersed Bloch waves. The analysis uses dynamical elastic scattering together with inelastic scattering. The impact parameter method is used to calculate interband transition rates from electron currents, with high-energy losses, distributed across the unit cell of the crystal. A good fit with experimental data is obtained.