
%0 Journal Article
%A Fox, AG 
%A Fisher, RM 
%T A Summary of Low-angle X-ray Atomic Scattering Factors Measured by the Critical Voltage Effect in High Energy Electron Diffraction
%J Australian Journal of Physics
%D 1988/06/01
%V 41
%N 3
%P 461-468
%K 
%R https://doi.org/10.1071/PH880461
%U https://www.publish.csiro.au/paper/PH880461 
%X A summary of all the accurate (-0.1%) low-angle X-ray atomic scattering (form) factors for cubic and hexagonal close-packed elements which have been determined by the critical voltage technique in high energy electron diffraction (HEED) is presented. For low atomic number elements (Z ~ 40) the low-angle form factors can be significantly different to best free atom values, and so the best band structure calculated and/or X-ray measured form factors consistent with the critical voltage measurements are also indicated. At intermediate atomic numbers (Z:::: 40-50) only the very low-angle form factors appear to be different to the best free atom values, and even then only by small amounts. For heavy elements (Z ~ 70) the best free atom form factors appear to agree very closely with the critical voltage measured values and so, in this case, critical voltage measurements allow accurate determinations of Debye-Waller factors. 
