MULTIPLE-FILM BACK-REFLECTION CAMERA FOR ATOMIC STRAIN STUDIES

摘要

A new back-reflection X-ray diffraction technique, which eliminates some of the principal limitations and reduces the remaining limitations Imposed by conventional single-film hack-reflection methods, was developed through use of a multiple-film camera containing four parallel films separated by known distances. Diffraction angles were calculated by determining the change in radius of the diffraction ring from film to film. In the analysis of a polycrystalline aggregate, the atomic spac¬ing of a particular set of crystal planes in essentially one orientation is determined from the calculated diffraction angle. Diffuse diffraction patterns could he analyzed by the multiple-film technique with greater accuracy than could be obtained with conventional cameras. Calibration of the multiple-film camera with a gold powder standard for a set of planes having a reported atomic spacing of 0.91008 A yielded a possible accuracy of- the atomic spacing of approximately ±.4x10-5 A.