A New Method of X-Ray Diffraction Topography Using Monochromatic Divergent Beams Made by a Curved Crystal

Abstract

A new method of X-ray diffraction topography is proposed, in which monochromatic divergent beams made by a curved crystal are used as the incident beam and diffracted successively from different positions of the specimen crystal by oscillating it. The method is simple in mechanism and easy in experimental procedure. As a remarkable merit, a topograph of fairly high resolution and contrast is obtained from the whole region of the specimen even if it is heavily distorted. Some reflection as well as transmission topographs from a LiF crystal and a Si wafer locally coated with oxide film are shown and compared with those taken by the Lang method. A modified use is also described in which the specimen and photographic plate are rotated step-wise and by which information on the relative misorientation of various parts of the specimen is given.