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International Union of Crystallography
Commission on Electron Diffraction (CED)

The electron microscope is a type of microscope that uses electrons to create an image of the target. It has much higher magnification or resolving power than a normal light microscope, up to two million times, allowing it to see smaller objects and details. However, one does not need to be limited to just obtaining images, and within one instrument a very wide range of different techniques can be used including imaging in projection with resolutions of better than one Angstrom (0.1nm), obtaining diffraction patterns and measuring charge densities from regions as small as ten Angstroms as well as obtaining information about the chemical composition and band structure also from regions of about ten Angstroms. Resolution is limited by spherical and chromatic aberration, but a new generation of aberration correctors have been able to overcome spherical aberration allowed the production of images with sufficient resolution to show carbon atoms in diamond separated by only 0.89 Angstrom (89 picometers) and atoms in silicon at 0.78 Angstrom (78 picometers) at magnifications of 50 million times. The ability to determine the positions of atoms within materials has made the HRTEM an indispensable tool for nano-technologies research and development in many fields.

The field is rapidly advancing, with the ability to obtain three-dimensional information now at close to five Angstroms as well as time-resolved diffraction information in the picosecond regime.

This web page provides links to some research groups, materials, books, and software in the field, emphasizing work in electron diffraction and cryomicroscopy, but it also includes material on microanalysis (eg ELS, EDX) and HREM.