Absolute Measurement of the Atomic Scattering Factors of Aluminum on Powder in Transmission

Abstract

Measurements have been made of the absolute x-ray scattering factors for the first three reflections---(111), (200), and (220)---in aluminum, in symmetrical transmission on a powder sample. Monochromatized Mo $K\ensuremath{\alpha}$ radiation was applied. The form factors obtained were significantly less than the theoretical Hartree-Fock free-atom values, and even lower than the values calculated for the ten neon-core electrons. These findings were in agreement with previous measurements on powders, and on an imperfect single crystal in transmission. Qualitatively, the x-ray diffraction data correspond to the results of Compton-scattering measurements, which suggest that the momentum density for the aluminum core is more extended in momentum space than that for the Hartree-Fock free-atom calculation.