TEM grid holders and STEM imaging holders
1- EM-Tec TG4 pin stub-based TEM grid holder for up to four TEM grids. The longer pin creates a distance from the stage adaptor to reduce electron and X-ray signals from the SEM stage.
2-TEM grids are clamped down by a top plate and a central brass screw. The hole size is Ø2.1mm with a 60° side angle on top and base to reduce electron and X-ray scattering interference from the holder.
3-Top plate removed: numbered positions with machined pockets and side grooves in the base to facilitate loading/unloading the TEM grids with fine pointed tweezers.
Imaging TEM specimens in an SEM
TEM specimens are very thin and therefore do not exhibit signal originating from their bulk. This enables improved surface imaging and increased spatial resolution - clear advantages for SEM/EDX studies of thin films, fine dispersions, inclusions, precipitations and low-Z materials. An SEM - or preferably a FESEM - can be used to check TEM specimens or FIB lamellae before inserting into an TEM.
There are two methods of imaging TEM specimens requiring different types of TEM grid holders:
- surface imaging and investigation requiring TEM grid holders
- STEM imaging which requires a special TEM grid holder with integrated conversion plate
EM-Tec TEM grid holders
Only available with a standard 3.2mm pin. They can be used on other SEMs, when an EM-Tec SEM stub adaptor is used.
EM-Tec PS11 mini pin stub holder for a single TEM or FIB grid. TheTEM grid rim rests on a ledge: in the middle of the cavity there is dimple to provide a non-touching area for the mesh of the grid. A groove is provided for easy loading/unloading of the TEM grid with fine tweezers. The TEM grid is not clamped. This holder is used for quickly checking a TEM grid in the SEM or as a TEM grid holder for a carbon evaporator.
EM-Tec PS14 mini pin stub holder for four TEM or FIB grids. TEM grid rim rests on a ledge; in the middle of each cavity there is dimple to provide a non-touching area for the mesh of the grid. Grooves are provided for easy loading/unloading of the TEM grids with fine tweezers. The TEM grids are not clamped. This holder is used for quickly checking up to four TEM grids in the SEM or as a grid holder for a carbon evaporator.
EM-Tec TG4 TEM grid holder securely holds up to 4 TEM grids (each). Numbered positions with machined pockets and side grooves for loading/unloading the TEM grids. The TEM grids are clamped down by the top plate and a central brass screw. Precision machined from vacuum grade aluminium. Through hole size is Ø2.1mm with a 60° side angle on top and base to reduce electron and X-ray scattering interference from the holder.
EM-Tec ST1 STEM imaging holder
Facilitates STEM imaging of TEM specimen in an SEM or FESEM. It is a cost-effective method for adding STEM capabilities to your SEM at a fraction of the cost of a dedicated STEM holder and detector. The STEM imaging holder image quality rivals that of a dedicated STEM detector system. The limiting factors are specimen thickness and accelerating voltage of the SEM.
EM-Tec ST1 STEM imaging holder
Uses the Everhart-Thornley SE detector in the SEM chamber. The TEM grid is placed in the STEM imaging holder and the holder is positioned under the electron beam (typically in the centre of the SEM stage). The TEM specimen is scanned with the electron beam and the STEM image is formed by converting the transmitted electrons, which hit the platinum conversion plate, into secondary electrons. The secondary electrons (holding the STEM image information) are collected by the SE detector in the specimen chamber.
It is best to use high accelerating voltages (25-30kV) and thin specimens to increase the transmitted electron signal. The STEM imaging detector is provided with a black conductive plastic electron absorption sleeve which is placed between the polepiece and the EM-Tec ST1 STEM imaging holder. The sleeve absorps the secondary and backscattered electrons emitting from the specimen surface.
Constructed from vacuum grade aluminium, brass (TEM grid holder), platinum for the electron conversion plate and conductive plastic sleeve. Platinum is used for the conversion plate due to its high secondary electron signal, stability and corrosion resistance. The STEM imaging holder provides a genuine signal from the converted transmitted electrons, resulting in high contrast STEM imaging.