High-voltage electron diffraction study of structure factors of Pd and Pt

In order to determine the atomic scattering factors of Pd and Pt for g = 200 and 220 reflections as well as their temperature factors, we measured critical voltages under the systematic excitation and the splitting of Kikuchi lines of high-order reflections. A simulation of the many-beam dynamical diffraction showed that the absorption of electrons in Pd and Pt is so significant as to narrow the splitting of kikuchi lines by 1.1% and 5.5%, respectively. The analysis of the experimental results, taking into account the absorption effect, determined the atomic scattering factors for both elements and the B-factor of Pd with quite good accuracies. In contrast, the B-factor of Pt involves relatively large uncertainty, owing to diffuse Kikuchi lines.