Is it feasible to determine the bonding charge density of stoichiometric γ-TiAl through structure factor measurements?

Abstract

All the experimental methods for the measurement of structure factors are reviewed with emphasis on determining the electron charge-density distributions of intermetallic alloys, in particular γ-TiAl. The techniques discussed include X-ray diffraction, X-ray pendellösung methods, γ-ray diffraction and high-energy electron diffraction (intersecting Kikuchi line, critical voltage and convergent-beam rocking-curve procedures). All these methods (except for electron diffraction) require high-quality single crystals which seem impossible to prepare for equiatomic γ-TiAl. However, the critical-voltage electron diffraction measurements presented in this work indicate that the 001, 110, 111, 200, 002, 220 and 202 structure factor amplitudes of stoichiometric γ-TiAl can be determined with sufficient accuracy for a charge-density study provided that great care is taken.