Measurement of the Scattering Factor of Copper in a Perfect Crystal

Abstract

Several studies of the scattering factors of metal powders have shown that the charge distribution is more spread out than that calculated by the Hartree-Fock (HF) method for free atoms. On the other hand, measurements on gases have yielded agreement with the HF calculations. In order to distinguish whether the disagreement in the case of the metals arises from the powder measurement technique or from solid-state effects, we have measured the scattering factor of copper in a nearly perfect crystal and compared the result with that obtained previously on copper powder; we find agreement within experimental error. The inference from this result is that the previous powder measurements on aluminum, which yielded a scattering factor even lower than that calculated for the core electrons by the HF method, are also reliable.