DETERMINATION OF STRUCTURE FACTORS, LATTICE STRAINS AND ACCELERATING VOLTAGE BY ENERGY-FILTERED CONVERGENT-BEAM ELECTRON-DIFFRACTION

Transmission electron microscopes with integrated imaging energy filters make it possible to acquire two-dimensional energy-filtered convergent beam electron diffraction patterns. Zero-loss filtered diffraction patterns can be compared quantitatively with computer simulations and by this the underlying crystallographic parameters can be determined. High-index reflections are used to measure lattice strain with high accuracy and also to determine the accelerating voltage. Low-index reflections are used to measure structure factors. For structure factor determination, we have modified the refinement method of Zuo and Spence [Ultramicroscopy 35 (1991) 185] to include a global optimization algorithm which is a variant of the simulated annealing procedure.