ELECTRON MICROSCOPY – AN OVERVIEW

Abstract

The electron microscope (EM) is one of the most widely used instruments in research laboratories and is central based to micro-structural analysis and therefore important to any investigation related to the processing. The SEM/TEM provides information relating to topographical features, morphology, phase distribution, compositional differences, crystal structure, crystal orientation, and the presence and location of various defects. The strength of the SEM lies in its inherent versatility due to the multiple signals generated, simple image formation process, wide magnification range, and excellent depth of field. Later The SEM has more than 300 times the depth of field of the light microscope. The higher magnifications of the SEM are rivaled only by the transmission electron microscope (TEM) which requires the electrons to penetrate through the entire thickness of the sample. TEM images allow researchers to view the samples on a molecular level, making it possible to analyze structures and texture clearer and resolute which is useful in the study of crystals and metals and also has industrial applications.  As a result, sample preparation of bulk materials through TEM is tedious and time-consuming compared to the ease of SEM sample preparation and may also damage the microstructure.