Developments in Application of High Voltage Electron Microscope

Some applications of high voltage electron microscope (HVEM) at Hitachi are reviewed. Accompanied by the development of HVEM, applications for many kinds of fields are studied. In the field of electron diffraction, the critical voltage effect was observed for the first time. It has been shown that the intensity of 222 reflection from aluminium become minimum at about 600 kV. In biological fields, higher resolution images of sectioned specimens can be obtained. Stereoscopic observation method of thick sectioned specimen ( ~ 1 fim) has been established and some new information obtained. The possibility of observing living materials has also been investigated. A new environmental cell is developed, and wet specimens are observed. The irradiation effect on a living material is also studied with spores. Electron microscope image within the fatal dose (2 x 10~6 C/cm2) are too poor to obtain new information. In the materials science field, the coincidence relation of grain boundary in Fe alloy has been studied. Key words: high voltage electron microscope (HVEM), critical voltage, sectioned specimen, stereoscopic observation, living material, environmental cell, irradiation effect, coincidence relation The accelerating voltage of conventional transmissio