SEM or scanning electron microscope uses electrons for imaging, in a similar way that light microscopes use visible light. They use a specific set of coils to scan the beam in a raster-like pattern and use the electrons that are reflected or knocked off the near-surface region of a sample to form an image. Since the wavelength of electrons is much smaller than the wavelength of light, the resolution of SEMs is superior to that of a light microscope.
Scanning Electron Microscope is an electron microscope that scans a sample using a focused beam of electrons and magnifies it from 10 times to 300,000 times. Learn more about the scanning electron microscope, its uses, and types in this infographic.
The Scanning Electron Microscope (SEM) uses high-energy electrons to produce images of a solid specimen. SEM’s high-resolution electron imaging reveals various details about the sample including chemical composition, external morphology, shape, the orientation of materials and crystalline structure. It is used in forensic laboratories for examining the evidence, testing & quality control labs for testing metals & materials and it is also used by medical researchers. There is arguably no other microscope that can compare with the SEM because it has higher magnification and greater depth of field abilities. Most SEMs are easy to operate and have user-friendly interfaces.
Advantages of an SEM -
Advantages of a Scanning Electron Microscope include its wide array of applications, the detailed three dimensional and topographical imaging and the versatile information garnered from different detectors. SEMs are easier to operate with the proper training and advances in computer technology and associated software make operation user-friendly. SEMs are fast and often completing SEI, BSE and EDS analyses take less than five minutes. Along with that, the technological advances in modern SEMs allow for the generation of data in digital form.
Practical uses of SEM –
SEMs have a variety of applications in numerous scientific and industry-related fields critically in places where the characterization of solid materials is beneficial. In addition to topographical, morphological and compositional information, a Scanning Electron Microscope can detect and analyze surface fractures, provide information in microstructures, examine surface contaminants, reveal spatial variations in chemical compositions, provide qualitative chemical analyses and identify crystalline structures. SEMs also have practical industrial and technological applications such as semiconductor inspection, production line of minuscule products and assembly of microchips for computers. See the below infographic to know about the types of SEMs that are used for scientific and industrial applications.