Analysis of SEM Electron Backscattered Kikuchi Patterns Using a CCD Detector and a Macintosh Computer

The existence of electron backscattered (Kikuchi) patterns (EBSP) in the scanning electron microscope (SEM) is well known. The principal application of EBSP has been to determine the crystallographic orientation of bulk samples from materials with cubic symmetry. More recently the technique has being used to study crystallographic distortions and make space group determinations. An unexploited application of EBSP is that of phase identification, for example in metallographically prepared cross sections of solders and brazes. We have adapted EBSP to the general problem of crystallographic analysis of materials in an SEM though the development of high quality imaging hardware and interactive analysis software. Though visually complex, EBSP patterns exhibit interplanar spacing data comparable to Selected Area Diffraction (SAD) in TEM. After correcting for projection distortion, the angular information in a typical EBSP pattern is also comparable in precision to SAD (∼±1°), but, significantly, includes a much larger solid angle (∼60°) of reciprocal space which typically includes several crystallographic zones simultaneously.