Abstract
The ‘Pendellösung’ intensity beats of white radiation diffracted from copper whiskers have been measured by the energy-dispersive diffraction technique using a solid-state detector. The atomic scattering factors of copper were evaluated by measuring the positions of the intensity extrema and utilizing the dynamical diffraction theory for six low-order reflections. A tendency for the atomic scattering factors to increase with the wavelength was observed in the range between 0·3 and 0·6 Å, which is attributed to the anomalous dispersion term f′ as calculated by Cromer (1965). The absolute atomic scattering factors, f hkl° obtained for five specimens with different thickness, were 21·80±0·06, 20·28±0·11, 16·75±0·08, 14·74±0·04, 14·36±0·06 and 12·46±0·06 for 111, 200, 220, 311, 222 and 400 reflections, respectively. These values are very close to those calculated by Wakoh and Yamashita (1971) who have taken into account the band structure of copper crystals.