The ability of electron microscopes to analyze all the atoms in individual nanostructures is limited by lens aberrations. However, recent advances in aberration-correcting electron optics have led to greatly enhanced instrument performance and new techniques of electron microscopy. The development of an ultrastable electron microscope with aberration-correcting optics and a monochromated high-brightness source has significantly improved instrument resolution and contrast. In the present work, we report information transfer beyond 50 pm and show images of single gold atoms with a signal-to-noise ratio as large as 10. The instrument's new capabilities were exploited to detect a buried Sigma3 {112} grain boundary and observe the dynamic arrangements of single atoms and atom pairs with sub-angstrom resolution. These results mark an important step toward meeting the challenge of determining the three-dimensional atomic-scale structure of nanomaterials.

A compact electron-spin-polarization manipulator is described which allows one to align the polarization in any desired direction in space. The system delivers a focused electron beam of typically 3–5 keV. Its application in spin-polarized low-energy electron microscopy for the study of magnetic domain structures is briefly illustrated.

A 1M-and a 4M-pixel monolithic CMOS active pixel sensor with 9.5×9.5 µm 2 pixels have been developed for direct imaging in transmission electron microscopy as part of the TEAM project. We present the design and a full characterisation of the detector. Data collected with electron beams at various energies of interest in electron microscopy are used to determine the detector response. Data are compared to predictions of simulation. The line spread function measured with 80 keV and 300 keV electrons is (12.1 ± 0.7) µm and (7.4 ± 0.6) µm, respectively, in good agreement with our simulation. We measure the detection quantum efficiency to be 0.78±0.04 at 80 keV and 0.74±0.03 at 300 keV. Using a new imaging technique, based on single electron reconstruction, the line spread function for 80 keV and 300 keV electrons becomes (6.7 ± 0.3) µm and (2.4 ± 0.2) µm, respectively. The radiation tolerance of the pixels has been tested up to 5 Mrad and the detector is still functional with a decrease of dynamic range by ≃ 30 %, corresponding to a reduction in full-well depth from ∼39 to ∼27 primary 300 keV electrons, due to leakage current increase, but identical line spread function performance.

TEAM I is the final product of the Transmission Electron Aberration-corrected Microscope (TEAM) Project, a collaborative project funded by the Department of Energy with the goal of designing and building a platform for a next generation aberration-corrected electron microscope capable of image resolution of up to 50 pm. The TEAM instrument incorporates a number of new technologies, including spherical- and chromatic-aberration correction, an all-piezo-electric sample stage and an active-pixel direct electron detector. This article describes the functionality of this advanced instrumentation, its response to changes in environment or operating conditions, and its stability during daily operation within the National Center for Electron Microscopy user facility.

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