The FEI ThemIS 60-300 STEM/TEM specializes in in-situ experiments – liquid cell, heating, biasing, and mechanical testing. Its main components are an X-FEG gun, image aberration corrector, Bruker SuperX energy dispersive x-ray spectroscopy (EDS) detector, and a Ceta2 CMOS camera. The image aberration corrector fully corrects for coherent axial aberrations up to 3rd order and partially compensates for 4th and 5th order aberrations resulting in TEM spatial resolution of 70pm. The Bruker windowless EDS detector has a solid angle of 0.7 steradian enabling high count rates with minimal dead time for fast STEM-EDS mapping. The high speed Ceta2 camera can acquire 4kx4k images at 40 frames per second for in situ movies or large dynamic range diffraction patterns. Installed STEM detectors include a grouped bright field (BF), annular BF, and annular dark field (ADF), as well as a separate high-angle ADF (HAADF) detector. The ADF detector is segmented, allowing for differential phase contrast. The microscope is equipped with a Lorentz lens for field-free imaging of magnetic materials. Special techniques have been developed for air free transfer of samples from glove box to the microscope.
The versatile 3-condenser column facilitates nanobeam diffraction imaging and fluctuation microscopy. The microscope is aligned at 60, 80, 120, 200 and 300 kV and the Ceta2 camera has good performance at all accelerating voltages.
The 5.2 mm pole gap of the FEI Super-twin objective lens is compatible with a variety of holders available to users:
- Double-tilt holder (alpha/beta ~+/- 30°)
- Tomography holder (alpha > +/- 70°)
- Gatan 652 double-tilt heating holder (to 1000C)
- Protochips single and double tilt heating (to 1100C) and biasing holders
- Hummingbird single tilt biasing holder for user-defined MEMs devices
- Hysitron PI-95 mechanical testing holder for compression, tension, and biasing during mechanical testing
- Liquid nitrogen double-tilt holders for materials science and cryo-transfer of biological samples
General Specifications
| Accelerating Voltage | 60, 80, 120, 200, and 300 kV |
| TEM Information Limit (300kV) | 0.07 nm |
| TEM 3rd order spherical aberration | <1 µm (adjustable range +/- 50 um) |
| STEM Resolution (300kV) | 0.136 nm |
| STEM Spherical Aberration Cs | 1.2 mm |
Detectors
| EDS | Super X – four windowless silicon drift detectors with a total solid angle of 0.7 steradians and 140 eV energy resolution. |
| STEM | HAADF, segmented ADF, ADF, BF |
| HRTEM/Diffraction/Movies | FEI Ceta2 4k x 4k CMOS with scintillator, 40 fps. |
Specimen Holders
| Temp range | Alpha tilt | Beta tilt | |
| FEI low background double tilt for EDS | – | ±33° | ±26° |
| Hummingbird Tomography holder for tomography and EDS | – | ±70°/±70° | – |
| Protochips double tilt holder for in-situ heating and biasing and EDS | 23°C-1000°C | ±30° | ±11° |
| Protochips single tilt holder for in-situ heating and biasing | 23°C-1000°C | ±30° | |
| FEI low background double tilt for general use with hexring for magnetic samples | – | ±30° | ±26° |
| FEI single tilt for general use | – | ± 30° | – |
| Gatan 652-Ta double tilt heating holder | 23°C-1000°C | ±30° | ±26° |
| Gatan 636-DH low background DT liquid nitrogen cooling holder | -170°C/ 100°C | ± 30° | ±26° |
| Gatan 915 Cryo-transfer LN2 DT holder | -170°C/ 100°C | ± 30° | ±26° |
| Hysitron PI-95 Mechanical compression, tension, biasing holder | – | ± 30° | – |
| Gatan 654 Mechanical straining holder | – | ± 30° | – |
| Hummingbird Biasing Holder for MEMS devices | – | ± 30° | – |
