Scanning electron microscopy consists of an electron gun to emit electrons that are focussed into a beam, with a very tiny spot size of ~5 nm. Electrons are accelerated to energy values in the range of a few hundred eV to 50 KeV, then rastered over the surface of the specimen by. A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. With a magnification range of 10 to over 300,000, SEM can properly analyze specimens down to a resolution of a few nanometers. In order to understand which model best fits your research process, it is essential to understand the exact diference between them. The optical microscope is the most popular and. OUTLINE Introduction to scanning probe imaging • Electron gun and electromagnetic lenses • Principles of backscattered and secondary electron emission and their dependence on sample composition, topography, voltage, detector position, sample tilt, etc.
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