Diffraction from a Natural Grain Boundary in a Magnetite Bicrystal

The structure of a natural small-angle boundary in a magnetite bicrystal was investigated by X-ray diffraction. This boundary was a "general" type with a mixed twist and tilt character. The grain-boundary reflections observed around an 040 matrix reflection were in good agreement with those predicted by Boll-mann's O-lattice theory. These extra reflections appear to arise from a predominantly planar dislocation network. The structural width of the boundary, determined from the length of the relrods of the grain-boundary reflections, was of the order of four unit cells, close to the average spacing of the expected dislocation network.