Description
Scanning electron microscopy (SEM) is a technique used for observation and analysis of the micro- and nanostructure of sample surfaces. The combination of SEM with a Focused Ion Beam (FIB-SEM) makes it possible to obtain sequential cross sections through the sample, which can be constructed into a full 3D representation of the internal structure. Using a Gas Injection System (GIS), materials with various electrical properties can be added by vapor deposition from a suitable gas to avoid artefacts due to milling. For soft materials, like emulsions and foods, the microscope can be used under cryogenic conditions (cryo-(FIB-)SEM). X-rays are emitted when the electron beam hits a sample, with an energy that is characteristic for each element. These can be detected with an Energy Dispersive X-Ray Detector (EDX), which enables identification of the composition and measurement of the abundance of elements in a sample. This equipment is part of the equipment portfolio of Unilever made available for sharing through Shared Research Facilities.
Technical Details
FIB-SEM Zeiss Auriga (Crossbeam)
- Ultra high-resolution field emission scanning electron microscope
- Schottky Field Emitter
- Focused Ion beam (Ga liquid metal ion source)
- Single Gas Injection System (GIS) – Platinum precursor
- Charge compensation
- Inlens, SE (Everhart-Thornley) and EsB (Energy and Angle Selective) detection
- SmartSEM user interface
- Gatan Alto2500 cryotransfer(/coating) system
- EDX Oxford 80 mm detector – Aztec user interface
- Resolution down to 1 – 2 nm (at 30 – 1 kV), Ga FIB resolution ~ 3 nm
Applications
Wide range of applications in the area of food science, life science, plant science and material science.
Complementary Techniques
(cryo)-TEM
Sample preparation facilities
State-of-the-art facilities for sample preparation are available in the WEMC, among which:
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Sputter coating and carbon coating
- Critical point drying
Especially for cryo-samples:
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Plunge freezing
- Mirror freezing
- Freeze substitution (Leica AFS)
- High pressure freezing (Leica HPM100)
- Cryo-ultramicrotome (Leica UC7/FC7) including glove box to provide low humidity environment