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 Fitler (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 offeres 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 K2 IS direct electron detector capable of 4kx4k low-dose TEM imaging with single electron sensitivity at 40 frames per second using electron counting to elimenate detector readout noise. The K2-IS is also operable as a 2kx2k in-situ imaging and scanning diffraction 4D-STEM detector at 400 frames per second (800/1200/1600 frame per second available for smaller fields of view). TEAM I is also equipped with two 2048×2048 slow-scan CCD cameras (Gatan US1000); one is bottom mounted for high-resolution TEM imaging and one is mounted after the Gatan Imaging Filter (GIF). The GIF can be used for electron energy loss spectroscopy in both TEM and STEM modes.
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
- 4D-STEM with the K2-IS for ptychography, strain mapping, 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
- Off-axis TEM holography with an electrostatic biprism
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 |
