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Electron Microscopy

Environmental Molecular Sciences Laboratory (EMSL)

National Center for Electron Microscopy (NCEM)

Electron microscopy is a unique and indispensable tool for materials characterization because it is the only technique that provides information on the inner structure of materials at a high spatial resolution. In a transmission electron microscope, a high-energy electron beam penetrates an extremely thin slice of material to form a transmission image of the sample's interior structure. The resulting micrographs carry quantitative information on the property-controlling characteristics of materials such as internal interfaces, defects, structure, bonding, and composition. Electron microscopy is used to characterize advanced materials, establish the link between microstructure and properties, detect causes for failure, and discover new materials and phenomena in fundamental materials science.

NCEM provides the U.S. electron microscopy community with advanced instrumentation for electron-optical characterization of materials. The NCEM houses two unique high-voltage electron microscopes--the 1 MeV atomic-resolution microscope (ARM), which reaches the highest resolution in the United States, and the 1.5 MeV high-voltage electron microscope (HVEM), which provides the highest energy. In addition, the Center houses several smaller mid-voltage microscopes, including a 200 keV analytical electron microscope (AEM) and a 200 keV high-resolution electron microscope (HREM). A 200 keV in-situ microscope (ISM) has recently been added, and a computer-facilitated one-Ångstrom microscope (OÅM) is being acquired. Facilities for specimen preparation, image processing, and data analysis are also available to NCEM users.

With the OÅM, researchers will be able to explore the structures of many technologically important materials at the highest resolution available anywhere, and in a much larger number of viewing directions than with other microscopes, revealing the positions of both metal and light atoms, as shown in the simulation of an OÅM image of a grain boundary in rutile.

The Center is a national facility open to qualified researchers in materials science and associated disciplines. NCEM is located at Berkeley Lab.