This facility consists of four top-of-the line transmission electron microscopes, two of which are highly specialized instruments capable of extreme levels of resolution, achieved through spherical aberration correction. The facility is also equipped with extensive sample-preparation capabilities. The scientific interests of the staff focus on understanding the microscopic origin of the physical and chemical behavior of materials, with specific emphasis on in-situ studies of materials in native, functional environments.
This is a state-of-the-art dedicated 200kV cold field emission STEM with an aberration-corrector for the probe-forming lens. It is the first Hitachi-made aberration corrected electron microscope. The aberration corrector improves the spatial resolution (probe size) to <0.1 nm, while boosting the probe current by a factor of 10. The instrument is optimized for spectroscopic imaging and simultaneous acquisition of “Z-contrast” images and electron energy-loss spectra. It is equipped with five detectors for various settings using different convergent angles and collection angles in annular-dark-field imaging. It is also equipped with a high resolution electron energy-loss spectrometer which can routinely achieve an energy resolution of 0.35eV at zero energy-loss. The instrument is shielded within a metal box to reduce acoustic noise. A SDD EDX detector will be installed very soon to perform chemical analysis for heavy elements at atomic resolution. The Hitachi STEM is particularly good at resolving the chemical and electronic information of materials at the deep nanoscale.
This instrument is the first 80-300kV field-emission environmental transmission electron microscope to be installed in the US with an objective-lens aberration corrector. It has a spatial resolution of 0.08nm in the high-resolution phase contrast mode, and is capable of achieving this resolution at unusually high pressures due to the differential pumping apertures and custom pumping arrangement that is incorporated with the system. The maximum gas pressure for the environmental-cell is about 20mbar for N2, with other maximum pressures dependent on the atomic weight of the gas. As a result, this instrument is uniquely well-suited to imaging the fundamental mechanisms of catalysis and catalyzed nanostructure growth. The instrument has also scanning transmission imaging (STEM), magnetic imaging, and chemical analysis capabilities. It has a Lorentz lens and a bi-prism for imaging electrostatic and magnetic potentials or fields in materials. It is also equipped with an energy dispersive x-ray spectrometer and an electron energy-loss image filter spectrometer. A mass-flow controlled catalytic reaction system capable of providing controlled pressures of gas mixtures will be installed in the near future.
Contact: Lihua Zhang
This is the center’s workhorse instrument. It is a 120-200kV scanning transmission and transmission field-emission electron microscope (STEM/TEM) for high-resolution analytical structural characterization. It is equipped with a chottky field-emission gun and two exchangeable objective-lens pole-pieces (an ultra high-resolution pole-piece with a 0.19 nm point-to-point resolution and a ±20° sample tilt, and a high-resolution pole-piece with a 0.23 nm point-to-point resolution and a ±40° sample tilt). The instrument is also equipped with an energy dispersive x-ray spectrometer for chemical analysis, and heating and cooling stages for in-situ experiments and dynamic observations. An electron energy-loss spectrometer will be added in the near future. It is a user-friendly electron microscope. Users and students can be trained to operate the instrument.
Contact: Kim Kisslinger
The JEOL JEM-1400 LaB6 120KeV transmission electron microscope is an easy-to-use, high contrast, instrument with excellent imaging and analytical capabilities in one compact package. With an easily changeable accelerating voltage range of 40-120KeV, the JEM-1400 TEM is highly suitable for polymer, biological, and materials science applications. New software included with the JEM 1400 TEM provides a complete set of tutorials and user guides to help the beginning microscopist familiarize themselves with the instrument, but also allow the more experienced user to explore and utilize more advanced features.
Contact: Kim Kisslinger
Sample preparation is a critical and often underestimated aspect of transmission electron microscopy. Sample preparation for TEM can be a complex and involving procedure drawing upon a variety of mechanical and non-mechanical methods. The method chosen for TEM sample preparation is highly specific to the material to be analyzed and the desired information to be attained. Thin high quality TEM samples should have a thickness that is roughly equal to the mean free path electrons that transmit through the sample, which may only be a few tens of nanometers. The CFN maintains an array of equipment enabling a variety of standard TEM sample preparation capabilities. While users are generally expected to carry out their own specimen preparation, guidance and expertise may be provided by CFN electron microcopy staff.
The EM Group has a full range of image processing and analysis software for the interpretation of data. These includes, one 4-core, dual quad MacPro, equipped with MacTempas (for HREM/STEM image simulation and exit-wave reconstruction), CrystalKit and Adobe Photoshop (Fovea Pro Image analysis plug-ins) and one 4-core dual-quad PC with Digital Micrograph, True Image (exit wave reconstruction), and Inspect3D / Amira (tomographic reconstruction).