| Research Abstract |
In order to identify the foreign atoms and their clusters in the materials by using electron microscopes, the inelastically scattered electrons which have suffered from the inner shell excitation were selected by energy spectrometer fabricated under the atom resolution electron microscopes, and reconstructed to be the images of atoms. Since the intensity of electrons with inner shell excitation 100-10,000 times smaller than the one of primary electrons, the exposure time necessary for recording the atom images becomes to be one minute to one hour. The images with such long exposures inevitably suffer from the drift if the specimen. To compensate the specimen drift, image movement was picked up and feed back to the shift of the specimen on the goniometer with piezo electric element. All processes including detection of drift and driving the goniometer with an accuracy of 0.02nm were carried out using a computer of PC 9801.
The drift of the specimen is not linear for a long exposure time at the atomic resolution level and the drift free goniometer system which was made at first was not sufficient in the driving mechanism. Thus the system was redesigned and reconstructed. Since it was expected, the image resolution of 0.2nm can be achieved by the 348(]SY.+-。[)3 eV energy loss electrons at 200kV,high T<@D2c@>D2 superconducting materials with Ca atoms were recorded using Ca-L<@D22,3@>D2 energy loss electrons with 40-120 sec exposures. Since the exposure time was not sufficient to reveal the images of Ca atoms clearly, some image processings have applied to reveal the single, double and triple Ca atom low and got reasonable Ca atom images.
New theoretical calculation of the potential localization for inelastic scattering at about 100kV energy loss have been calculated. Observation on the phase transformation of Ti alloy were also carried out.
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