CSEMs (conventional SEMs with a thermic electron source) and FE-SEMs (field emission SEMs with a field emission electron source) from ZEISS deliver high resolution imaging and superior materials contrast. The scanning electron microscope (SEM) uses a focused beam of high-energy electrons to generate a variety of signals at the surface of solid specimens. X-ray analysis is difficult with a coating of a heavy metal, so carbon coatings are routinely used in conventional SEMs, but ESEM makes it possible to perform X-ray microanalysis on uncoated non-conductive specimens; however some specific for ESEM artifacts are introduced in X-ray analysis. A wide range of magnifications is possible, from about 10 times (about equivalent to that of a powerful hand-lens) to more than 500,000 times, about 250 times the magnification limit of the best light microscopes. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. In an SEM, as in scanning probe microscopy, magnification results from the ratio of the dimensions of the raster on the specimen and the raster on the display device. BSE detectors are usually either of scintillator or of semiconductor types. In environmental SEM (ESEM), the chamber is evacuated of air, but water vapor is retained near its saturation pressure, and the residual pressure remains relatively high. Electrons have a much shorter wavelength and … [32], The first commercial development of the ESEM in the late 1980s[33][34] allowed samples to be observed in low-pressure gaseous environments (e.g. High-quality 2D SEM images, on the other hand, are widely available. Scanning electron microscopy (SEM) gives information of the microstructure of coated surface, distribution of photocatalyst on the substrate surface, homogeneity, and morphology of particles in the coating. Updates? However, BSE are often used in analytical SEM, along with the spectra made from the characteristic X-rays, because the intensity of the BSE signal is strongly related to the atomic number (Z) of the specimen. Non-conducting materials are usually coated with an ultrathin coating of electrically conducting material, deposited on the sample either by low-vacuum sputter coating or by high-vacuum evaporation. 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