Experimental determination of low order structure factors in the intermetallic compound TiAl

Rocking curves from several low order reflections in TiAl were recorded in digitized form using energy-filtered convergent beam electron diffraction in a transmission electron microscope. The low order reflections studied were 001, 002, 200, 111, 110, 220, 202, 113, and 311. These experimental rocking curves were simulated using computations based on the dynamic theory of electron diffraction. From these simulations, values of the X-ray structure factors for these reflections were deduced, and then used to determine charge difference maps for varioius plane sections in TiAl. These charge difference maps were compared with theoretical predictions, and it was found that there is a considerable degree of agreement between theory and experiment.