Transmission Electronic Microscopy (english version)
Technical manager
Scientist Director
Philippe MOREAU
The equipment and activities described on this page are part of the GIS "CIMEN" which is currently under construction. It can be found on the website https://www.gis-cimen.fr/
Equipments
1- Nant'Themis (S/TEM Themis Z G3 from Thermo Fisher Scientific)
This new generation microscope was installed in 2018. Its exceptional configuration (monochromator, probe corrector, energy filter with direct detection camera) was the first to be installed in Europe. Having been defined to be open and interdisciplinary, the Nant'Themis is available to :
- IMN researchers,
- Nantes laboratories
- regional and national laboratories,
- industries working in fields such as metallurgy, biology, energy...
The Nant'Themis microscope was funded by the « 2015-2020 Contrat de Plan Etat Région (CPER)
The cost of the microscope (>3.5M€) was supported by
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- ETAT 18%
- FEDER (Europe) 50%
- REGION Pays de la Loire 14%
- Nantes Métropole 14%
- CNRS 4%
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The CNRS DR17 Regional Delegation financed a large part of the developpement work to fit out the MET room and the external accesses. The inauguration took place on 7 February 2019.
Nant'Themis is equipped with a Schottky X-FEG gun (high brightness and high stability), a monochromator (achievable energy resolution < 100 meV) and a probe corrector (resolution : 60 pm @ 300 kV in STEM). It is aligned at accelerating voltages of 300, 200 and 80 kV chosen according to the sample and the techniques used to characterise it.
In addition to "classical" electron diffraction and imaging, other more recent techniques or those under development can be used. These include:
- Tomography with the use of data acquisition and reconstruction software (TEM and STEM)
- Electron precession (especially for electron crystallography) and phase and orientation mapping (Digistar and Astar from Nanomegas)
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EDX spectroscopy (SuperX system with 4 detectors): quantitative elemental analysis, mapping, 3D reconstruction
- Light element imaging in STEM (iDPC)
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Ultrafast image acquisition, in situ mode: up to 300 frames/s in 512*512 pixels with the Gatan OneView IS camera
- Diffraction imaging in STEM mode (Gatan STEMx)
Here are some examples of results obtained at IMN :
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HAADF image of a hexagonal perovskite Ba2.5Sr0.5NiSb2O9 along [010] and associated EDX maps of the elements Sb (green), Ni (blue) and Ba (yellow) (sample: IMN, C. Deudon, C. Payen, images: IMN, M. Caldes, N. Gautier, E. Gautron, July 18). One of the Sb sites has an occupancy factor of 50%, the other 100%. On the right, theoretical crystal structure and associated simulation (programme: Dr Probe, thickness 5.7 nm) |
HAADF, iDPC and dDPC images of GaN along [11-20] (sample: Thermo Fisher Scientific, images: IMN, E. Gautron, Nov 18). The nitrogen atoms separated by 63 pm are clearly visible in dDPC. The contrast in iDPC is related to the projected potential, that in dDPC to the charge density in the sample (i = integrated, d = differentiated, DPC = Differential Phase Contrast)
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| Evolution de la morphologie de nanoparticules métalliques avec la température (Porte-objet NanoEx-i/v, images : IMN, E. Gautron, déc. 18). |
Images MET en champ clair de précipités dans une matrice d’aluminium (échantillon : G. Doumenc, R. Gautier, L. Couturier, images : IMN, E. Gautron, déc. 18). |
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Cartographie d’orientations d’une couche de TiO2 anatase déposée par PECVD sur substrat SiO2/Si Nant'Themis was one of the first microscopes in Europe to be equipped with a configuration combining a very high resolution energy filter (Gatan GIF Quantum 966 ERS) with a direct electron detection camera (Gatan K2 Summit) in addition to the conventional CCD camera. This camera technology greatly improves both energy resolution and signal-to-noise ratio of electron energy loss spectra (EELS) compared to a CCD camera. It allows to characterise highly sensitive to the electron beam samples using EELS.
Lien vers http://www.gatan.com/products/tem-imaging-spectroscopy/gif-quantum-k2-system Seven different holders are available depending on the application:
2- H-9000 NAR (Hitachi))
3- Autres équipements de préparation des échantillons
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Institut des Matériaux de Nantes Jean Rouxel,
Polytech Nantes,