X-Ray Diffraction Topography Utilizing Double-Crystal Arrangement of (+, +) or Non-Parallel (+, -) Setting

Abstract

A potential utility of the double-crystal arrangement of (+, +) or non-parallel (+, -) setting for obtaining a diffraction topograph is studied. The method is simple in mechanism and enables us to obtain well-defined images of imperfections from a large area of a specimen without any scanning mechanism in a rather short exposure time. Differing from the double-crystal arrangement of the parallel setting usually used, the present method allows us to obtain topographs for any reflection of any kinds of crystals irrespectively of the first crystal. For the first crystal is employed the asymmetric 111 reflection of a nearly perfect Ge crystal to take photographs from a large area in a rather short exposure time by using a usual sealed-off X-ray tube. As examples are shown some transmission topographs taken with Cub α1 from a LiF crystal, and Si web crystals as grown and after heat-treated.