ULTRA-HIGH VOLTAGE ELECTRON-MICROSCOPY AND ITS APPLICATIONS TO NEW RESEARCH FIELDS IN MATERIALS SCIENCE

The electron channeling, whose rate is proportional to the relativistic mass of an electron, occurs at high accelerating voltages by interaction among many simultaneously excited electron waves. As a result, the maximum observable specimen thickness markedly increases with increasing the voltage, so that essentially the same behavior of lattice defects in almost all materials can be observed dynamically as that in bulk specimens with an ultra-high voltage electron microscope (UHVEM). In situ experiments with UHVEM have been carried out in many research fields of natural science, particularly materials science. In the present article, in these experiments, only the formation process of non-equilibrium phases and its related phenomena are mentioned as one of topics in the electron beam science and engineering which has been developed recently with UHVEM. © 1990, The Iron and Steel Institute of Japan. All rights reserved.