Lj. Allen et al., MODELING THERMAL DIFFUSE-SCATTERING IN ELECTRON-DIFFRACTION INVOLVINGHIGHER-ORDER LAUE ZONES, Acta crystallographica. Section A, Foundations of crystallography, 53, 1997, pp. 421-425
The importance of thermal diffuse scattering (TDS) in electron diffrac
tion contrast is well known. Experiments involving higher-order Laue-z
one (HOLZ) reflections are highly sensitive to variations in the TDS f
orm factors. The Einstein model for TDS gives excellent agreement with
experimental convergent-beam electron diffraction (CBED) patterns con
taining HOLZ lines provided that the absorption coefficients are not c
alculated using perturbative methods but instead are evaluated exactly
. This is in contrast to absorption potentials determined from experim
ents sensitive to beams in the zero-order Laue zone (ZOLZ) only, the u
se of which can be inconsistent with data sensitive to HOLZ beams. Her
e the features of the Einstein model important for the correct interpr
etation of the experimental data are analyzed and why it is inadequate
to treat HOLZ beams perturbatively is discussed.