OBSERVATION OF LATTICE FRINGES IN CONVERGENT-BEAM ELECTRON-DIFFRACTION PATTERNS

Mirror symmetry, no symmetry and glide symmetry of crystals are displa yed using interference (lattice) fringes appearing in overlapping disk s of convergent-beam electron diffraction (CBED) patterns. The lattice fringes with a spacing of 2.7 Angstrom of the 200 reflection of FeS2 have been observed in coherent CBED patterns with use of a JEM2010F el ectron microscope equipped with a field-emission gun. Two-dimensional interference fringes are shown in three overlapping disks taken from F eS2 at [111] electron incidence. It is demonstrated that such lattice fringes can be obtained even by an LaB6 electron source when using ima ging plates.