STEM Detector Knowledge base
– ThermoFisher Scientific –
TEM-standard Imaging on the Phenom Pharos G2 Desktop FEG-STEM
Low-kV STEM imaging of soft tissues for cell biology…
Product Brochure
Phenom Pharos Desktop SEM
Desktop STEM Detector & Sample Holder
Product Overview
The Phenom STEM (scanning transmission electron microscopy) detector enables transmission imaging modes for the Phenom Pharos Desktop SEM. STEM imaging offers increased visibility of sample morphology and reveals subsurface structural details at higher resolutions than conventional SEM. The small footprint and lower operating vacuum also provide a faster workflow compared to conventional STEM imaging for applications that do not demand atomic resolution imaging. This new imaging modality provides immense value to a variety of fields including nanomaterials, catalysts, pathology, and batteries.
STEM Imaging
Higher Resolution
With a resolution of < 1nm, STEM achieves a higher resolution than possible with secondary electron detectors.
Application Flexibility
Expand the range of applications accessible to users of any skill level with low-kV STEM imaging on a desktop SEM platform.
STEM Holder Features
The sample holder is compatible with standard 3 mm TEM grids. A clamp-based mount ensures that delicate samples are safely loaded and securely held in place during handling.
The STEM detector and its electronics are conveniently integrated into the holder. Switching between conventional SEM and STEM imaging modes is as simple as loading a new sample. Users can obtain a time-to-image of less than 40 seconds and select from three standard STEM imaging modes or explore custom configurations.
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Desktop STEM Detector
STEM Imaging Modes
Bright Field
(BF)
BF imaging collects on-axis electrons scattered by the sample. BF image contrast depends primarily on sample thickness and composition, where thicker areas containing heavier elements appear darker. With improved sensitivity to light elements, BF mode can be particularly useful for studying organic samples.
Dark Field
(DF)
DF imaging detects off-axis electrons that result from relatively lower diffraction angles. Image contrast depends on thickness and atomic number with brighter areas corresponding to local mass-thickness. DF imaging is more sensitive to atomic number differences in lighter elements, and is useful for a broad range of samples.
High Angle Annular Dark Field (HAADF)
HAADF imaging collects the off-axis signals at the highest scattering angles and is most sensitive to atomic number contrast, or Z contrast. HAADF is particularly sensitive to heavier elements such as metal atoms. This mode can be used to detect features that are harder to visualize with the other imaging modes.
Video of how to select the specific detector segments to investigate different diffraction angles between BF, DF, and HAADF STEM imaging.
