In a transmission electron microscope (TEM), a thin specimen (ideally ≤ 100 nm) is exposed to a high-energy (typically 60 - 300 keV) electron beam. Images generally contain contrast that may be due to crystallinity, atomic mass, or thickness variations within the sample. Crystallographic information can also be obtained from diffraction patterns. We can also collect elemental and chemical state maps via analysis of 1) emitted x-rays (Energy Dispersive Spectroscopy – EDS) or 2) the energy loss of electrons that have gone through the specimen (Electron Energy Loss Spectroscopy – EELS). All of our micrcosopes can also be operated in STEM mode which may be better in some cases for beam sensitive or low contrast samples.
|TEMs||Source||kV||Min. Resolution (Å)||Min. Probe Size (Å)||STEM||EDS||EELS||EFTEM|
|Tecnai G2 20 XTWIN||LaB6||80, 200||0.24||10||*||*||*||*|
|Talos F200X||XFEG||80, 200||0.12||1.6||*||* (SuperX EDS)|
|FEI Titan3 G2*||XFEG||60, 80, 200, 300||0.7||0.7||*||* (SuperX EDS)||*||*|
New users will generally start training first on the Tecnai. Please see individual instrument pages for details regarding training. Users can also get training on how to prepare their own samples with the assistance of MCL staff.
For users with a limited number of samples that do not wish to get trained on the TEM, the TEM staff scientists can help to determine the proper techniques, acquire and analyze the data that is needed for your samples.