Others were focusing of the electrons by an axial magnetic field by Emil Wiechert in 1899, improved oxide-coated cathodes which produced more electrons by Arthur Wehnelt in 1905 and the development of the electromagnetic lens in 1926 by Hans Busch. One significant step was the work of Hertz in 1883 who made a cathode-ray tube with electrostatic and magnetic deflection, demonstrating manipulation of the direction of an electron beam. Many developments laid the groundwork of the electron optics used in microscopes. See also: Transmission electron microscopy § History Reproduction of an early electron microscope constructed by Ernst Ruska This articles contains some general information mainly about transmission electron microscopes. Photoemission electron microscopy (PEEM) is similar to LEEM using electrons produced at surfaces by photonsĪdditional details can be found in the above.Low-energy electron microscopy (LEEM), used to image surfaces.Ultrafast scanning electron microscopy, version of SEM that can operate very fast.Electron microprobe similar to a SEM, but more for chemical analysis.Scanning electron microscope (SEM) is similar the STEM, but with thick samples.Scanning transmission electron microscopy (STEM) is similar to TEM with a scanned electron probe.Transmission electron microscopy (TEM) where swift electrons go through a thin sample.As the wavelength of an electron can be up to 100,000 times shorter than that of visible light, electron microscopes have a higher resolution of about 0.1 nm, which compares to about 200 nm for light microscopes. They use electron optics that are analogous to the glass lenses of an optical light microscope. A modern transmission electron microscope An image of an ant in a scanning electron microscopeĪn electron microscope is a microscope that uses a beam of electrons as a source of illumination. Not to be confused with Scanning tunneling microscope.
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