Introduction to Energy-Filtering Transmission Electron Microscope fundamental principles

For many years now, Conventional Transmission Electron Microscope (CTEM) has been used as an efficient tool to fulfill Nano scale analysis and imaging requirements of scientists and researchers of different areas. Despite the fact that CTEM is a very efficient tool, in some areas researchers must add specially designed equipment to this microscope in order to create desired conditions for observing and imaging their specific specimens. In this article, we introduce one of the most practical kind of CTEM that has been invented for over a decade namely, Energy-Filtering Transmission Electron Microscope (EFTEM). EFTEM has been designed by using physical principles of electron energy-loss spectrometry (EELS) and commercial in-column or post-column energy-filters introduced by companies like: ZEISS and GATAN. It can generate precise images from ultrastructure of different specimens belonging to different areas of research by using inelastically scattered electrons. The operation of these kind of energy-filters is straightforward and because of that acquiring element specific images within only a few minutes has become possible. For obtaining best results, a fundamental knowledge of the underlying physics of EELS and a systematic development of the technical details is necessary. Also it is important that users be able to know with certainty that EFTEM is the optimal equipment for their experiments. For aforementioned reason, detailed structures of available energy filters and applications of EFTEM in various fields are reviewed in the next article titled “Introduction to Energy-Filtering Transmission Electron Microscope structure and applications” that will be publish in the next issue of this journal.