ELECTRON BACKSCATTERING DIFFRACTION (EBSD): PROBLEMS AND PROGRESS

Electron backscattering diffraction, EBSD, is now well established as an important technique in scanning electron microscopy applied to crystalline materials. Early books on the subject (Dingley et al, 1995 and Schwartz et al 2000) indicate how long the technique has been in active development, while the status of the field is indicated by the presence of an extended section on EBSD in the latest edition of the standard text on scanning electron microscopy (Goldstein et al 2003). Nonetheless, there are many areas in which EBSD is not fully understood and not fully developed. One factor which limits the use of EBSD patterns is that there is, to date, no computer program to simulate the patterns. There are, of course, programs that simulate the positions of the lines using Bragg's law. These can be described as kinematic calculations. However, there are no programs that simulate correctly the intensity distribution in the patterns; there is no dynamical simulation. This means that, for example, there is a serious limit on the ability of EBSD to determine the lattice parameter of the crystal structure. There are good reasons for this: the computation is very complex. Nonetheless such a program could be written and it remains an outstanding challenge