Ag. Fox, IS IT FEASIBLE TO DETERMINE THE BONDING CHARGE-DENSITY OF STOICHIOMETRIC GAMMA-TIAL THROUGH STRUCTURE FACTOR MEASUREMENTS, Philosophical magazine letters, 68(1), 1993, pp. 29-37
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 gamma-TiAl. The t
echniques discussed include X-ray diffraction, X-ray pendellosung meth
ods, gamma-ray diffraction and high-energy electron diffraction (inter
secting Kikuchi line, critical voltage and convergent-beam rocking-cur
ve procedures). All these methods (except for electron diffraction) re
quire high-quality single crystals which seem impossible to prepare fo
r equiatomic gamma-TiAl. However, the critical-voltage electron diffra
ction measurements presented in this work indicate that the 001, 110,
111, 200, 002, 220 and 202 structure factor amplitudes of stoichiometr
ic gamma-TiAl can be determined with sufficient accuracy for a charge-
density study provided that great care is taken.