Electron microscope wavelength

The electron-optical performance of the EPMA system is indistinguishable from that of a conventional scanning electron microscope (SEM) thus, EPMA combines all of the imaging capabilities of a SEM with quantitative elemental analysis using both energy- and wavelength-dispersive X-ray spectrometry. ... 

Excitation of sample by bombardment with electrons, radioactive particles or white X-rays. Dispersive crystal analysers dispersing radiation at angles dependent upon energy (wavelength), detection of radiation with gas ionization or scintillation counters. Non-dispersive semiconductor detectors used in conjunction with multichannel pulse height analysers. Electron beam excitation together with scanning electron microscopes. 

Seeing the surface of a catalyst, preferably in atomic detail, is the ideal of every catalytic chemist. Unfortunately, optical microscopy is of no use for achieving this, simply because the rather long wavelength of visible light (a few hundred nanometers) does not enable features smaller than about one micrometer to be detected. Electron beams offer better opportunities. Development over the past 40 years has resulted in electron microscopes which routinely achieve magnifications on the order of one million times and reveal details with a resolution of about 0.1 nm [1], The technique has become very popular in catalysis, and several reviews offer a good overview of what electron microscopy and related techniques tell us about a catalyst 12-6],... 

The convenience of using X-rays for stmcture determination stems from the nature of their interactions with matter the wavelengths of radiation in the X-ray region of the electromagnetic spectmm are comparable to the sizes of atoms and interatomic distances that are to be analyzed. Although, in principle, interatomic distances can be determined by electron microscopy, unlike electron microscopic... 

Electron microscopy is widely used in the characterization of solids to study structure, morphology, and crystallite size, to examine defects and to determine the distribution of elements. An electron microscope is similar in principle to an optical microscope. The electron beam is produced by heating a tungsten filament, and focused by magnetic fields in a high vacuum (the vacuum prevents interaction of the beam with any extraneous particles in the atmosphere). The very short wavelength of the electrons allows resolution down to 0.1 nm. 

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