Scanning Electron Microscopy

Abstract

Scanning electron microscopy (SEM) is the most preferred method in microstructural analysis today. In this method, electrons accelerated by high voltage (0-30 kV) are focused on the sample. During the scanning of the surface of this focused electron beam, electrons and material atoms interact. Electrons and X-rays formed as a result of this interaction are collected by detectors. These signals coming to the detector are converted into digital signals and given to the computer screen. The image taken on the screen gives us information about the microstructure of our sample. In addition, SEM have the ability to perform microchemical analysis. Elemental analyzes of the surface can also be performed with the energy dispersive X-ray (EDX) feature. SEM has a much higher resolution and focusing depth compared to optical microscopes. For example, at 1000X magnification, the focal depth of the optical microscope is 0.1 μm, while the focal depth of the SEM is in the range of 30–40 μm. In today’s technology, very modern and superior scanning electron microscopes are produced and used.