This research area supports three electron-beam microcharacterization centers, which operate as user facilities, work to develop next-generation electron-beam instrumentation, and conduct corresponding research. Operating funds are provided to enable expert scientific interaction and technical support and to administer a robust user program at these facilities, which are made available to all researchers with access determined via peer review of brief proposals. Capital equipment funding is provided for instruments such as scanning, transmission, and scanning transmission electron microscopes; atom probes and related field ion instruments; related surface characterization apparatus and scanning probe microscopes; and/or ancillary tools such as spectrometers, detectors, and advanced sample preparation equipment.
Electron scattering has key attributes that give such approaches unique advantages and make them complementary to xray and neutron beam techniques. These characteristics include strong interactions with matter (allowing the capture of meaningful signals from very small amounts of material, including single atoms under some circumstances) and the ability to readily focus the charged electron beams using electromagnetic lenses. The net result is unsurpassed spatial resolution and the ability to simultaneously get structural, chemical, and other types of information from subnanometer regions, allowing study of the fundamental mechanisms of catalysis, energy conversion, corrosion, charge transfer, magnetic behavior, and many other processes. All of these are fundamental to understanding and improving materials for energy applications and the associated physical characteristics and changes that govern performance. (more (30KB))
The Electron Microscopy Center for Materials Research (EMC) at Argonne National Laboratory has an emphasis on in-situ capabilities and measurements, including observation of samples in magnetic fields, under ion beam irradiation, and within a range of environments. A variety of instruments and approaches are available including an electron microscope with unique capabilities for correction of chromatic lens aberrations, which affords users the possibility of pursuing 3D chemical imaging for characterization of buried interfaces and the study of hard/soft materials at low voltages below the displacement damage threshold. Research at EMC includes microscopy based studies on high-temperature superconducting materials, irradiation effects in metals and semiconductors, phase transformations, and processing related structure and chemistry of interfaces in thin films.
The National Center for Electron Microscopy at Lawrence Berkeley National Laboratory provides instrumentation for high-resolution, electron-optical microcharacterization of atomic structure and composition of metals, ceramics, semiconductors, superconductors, and magnetic materials. This facility includes, and provides users with access to, the TEAM I instrument, the most advanced scanning/transmission electron microscope in the world with unparalleled lateral spatial resolution of under 50 picometers. NCEM’s focus and major impact is in the following areas of research: defects and deformation; mechanisms and kinetics of phase transformations in materials; nanostructured materials; surfaces, interfaces and thin films; and microelectronics materials and devices.
The Shared Research Equipment (ShaRE)User Facility at Oak Ridge National Laboratory makes available state-of-the-art electron beam microcharacterization facilities for collaboration with researchers from universities, industry and other government laboratories. Particular emphases include compositional analysis via spectroscopic and other techniques, including state-of-the-art atom probe tomography. Most ShaRE projects seek correlations at the microscopic or atomic scale between structure and properties in a wide range of metallic, ceramic, and other structural materials. A diversity of research projects has been conducted, such as the characterization of magnetic materials, catalysts, semiconductor device materials, high Tc superconductors, and surface-modified polymers.
For more information about this research area, please contact Dr. George Maracas.