The TEAM Project
The Transmission Electron Aberration-corrected Microscope (TEAM) project was a multi-laboratory development project from 2003 – 2009 to integrate the latest advancements in electron optics, detectors, sample stages, and computational techniques into a suite of instruments freely available to the worldwide scientific community. The NCEM facility has 2 double-aberration corrected microscopes for atomic resolution imaging.
TEAM I Optics
TEAM I is a double-aberration-corrected (scanning) transmission electron microscope (STEM/TEM). The basic instrument is a modified FEI Titan 80-300 microscope equipped with a high-brightness Schottky-field emission “X-FEG” electron source, a source monochromator, a CEOS DCOR spherical-aberration STEM probe corrector, and a CEOS CEOS CCOR combined spherical/chromatic aberration TEM corrector, and a high-resolution Gatan Imaging Filter (GIF) Continuum K3 spectrometer with direct electron detection. The probe corrector corrects coherent axial aberrations up to 4th order, as well as 5th order spherical aberration and six-fold astigmatism. The image corrector corrects for coherent axial aberrations up to 3rd order, partially compensates for 4th and 5th order aberrations and corrects for chromatic aberrations. TEM and STEM modes and 0.15 eV energy resolution using source monochromation. This instrument also offers a variety of 4D-STEM operational modes including ptychography, strain mapping, differential phase contrast, microprobe scanning diffraction, orientation imaging, and more.
Stage
TEAM I is equipped with a conventional Compustage goniometer and has a pole piece gap of 5.4mm. The stage is compatible with a vast array of in-situ specimen holders of either 3mm or MEMS geometries.
Detectors
TEAM I is equipped with a Gatan K3 IS direct electron detector capable of 4kx4k low-dose TEM imaging with single electron sensitivity operating at 150 frames per second at full frame readout and up to 1500 frames per second for 256×256 readout using electron counting to eliminate detector readout noise. TEAM I is also equipped with a Dectris Arina electron-counting hybrid-pixel detector optimized for 4D STEM measurements at full beam currents. The Arina operates at frame rates up to 120 kHz with 96×96 pixel readout or at 30 kHz with 192×192 pixel readout. The GIF can be used for electron-counted electron energy loss spectroscopy and energy-filtered 4D-STEM with the K3-IS detector.
Experimental Modes
The microscope is primarily operated at 300 kV in the following modes (80 kV is also possible):
- Aberration corrected HR-TEM combined with monochromated 0.15 eV energy resolution with 60 pm spatial resolution suitable for focal-series reconstructions
- HR-STEM with 60 pm resolution with simultaneous use of BF and HAADF-STEM detectors
- Energy-filtered 4D-STEM with the K3-IS for ptychography, strain mapping, and other scanning nanodiffraction experiments
- High-speed 4D-STEM with the Dectris Arina, optimized for ptychography and other scanning nanodiffraction experiments
- Nanoscale and Atomic Electron Tomography in STEM and TEM modes
- Electron energy loss spectroscopy (EELS) for both energy filtered TEM (EF-TEM) and STEM-EELS
- Monochromated STEM-EELS for low-loss measurements and near edge core-loss bonding information with ~0.15e eV energy resolution
- Lorentz TEM (zero field at sample) with ~1nm spatial resolution
Specifications 300 kV
| Monochromator ON | Monochromator OFF | |
| Information limit | 0.05 nm (at 0.15 eV) | 0.05 nm |
| STEM resolution | 0.078 nm | 0.05 nm |
| Energy resolution (EELS) | 0.15 eV | 0.8 eV |
| TEM 3rd order spherical aberration | <1 µm, adjustable (± 50 µm) |
| TEM 5th order spherical aberration | ~4 mm |
| STEM 3rd order spherical aberration | <0.5 µm |
| STEM 5th order spherical aberration | <0.5 mm |
Specifications 80 kV
| Monochromator ON | Monochromator OFF | |
| Information limit | 0.07 nm (at 0.2 eV) | 0.15 nm |
| STEM resolution | 0.1 nm | 0.1 nm |
| Energy resolution (EELS) | 0.1 eV | 0.8 eV |
| TEM 3rd order spherical aberration | <1 µm, adjustable (± 50 µm) |
| TEM 5th order spherical aberration | ~8 mm |
| STEM 3rd order spherical aberration | <1 µm |
| STEM 5th order spherical aberration | <2 mm |
