Study of Thin Crystalline Films by Universal Electron Diffraction Microscope

In ordinary electron micrographs of MoO 3 crystals and mica films, which were obtained by using our universal electron diffraction microscope as ordinary electron microscope unit, there observed the well-known patterns which may be called “a group of closed contours” “dark spots” and “feather-like patterns” and further some patterns were also observed which may be called “wave-like patterns”. These patterns could be analysed by using the universal electron diffraction microscope as shadow microscope unit and high resolution electron diffraction camera. In the high resolution electron diffraction patterns and in the diffracted parts of shadow micrographs of bent, films of the crystals obtained by the universal electron diffraction microscope, the subsidiary maxima were observed which correspond to the intensity region in the reciprocal lattice extended in the direction normal to the film surface, and from the angular distances of the subsidiary maxima, the thickness of the film, Fourier coefficient of periodic electric field in the crystal and the external form of bent film could be obtained. Takagi arid König observed that MoO 3 crystal transforms into minute MoO 2 cystals when MoO 3 crystal is irradiated by intense electron beam. Besides the transformation of MoO 3 to MoO 2 , another hype of transformation MoO 3 →MoO 2 '→MoO 2 was observed in our experiment. The intermediate substance MoO 2 ' is observed as homogeneous parts in ordinary electron micrographs. By using the universal electron diffraction microscope as micro-diffraction unit, it has been possible to show that the intermediate substance belongs to monoclinic system and that some hexagonal holes produced in it are bounded by its net planes.