LIST installs Luxembourg’s most powerful electron microscope

The Luxembourg Institute of Science and Technology (LIST) recently installed an impressive electron microscope that now takes the title of the most powerful microscope of its kind in Luxembourg.

The size of the equipment known as Transmission Electron Microscope (TEM) means that it is now set up in its own dedicated laboratory, having made the journey as a kit all the way from Japan.

While the shipment arrived in late December, the complexity of the equipment meant that it took a further eight weeks to assemble and install it at the LIST site in Belvaux, and only recently became operational.

The TEM is unique in LIST and indeed Luxembourg, as it can analyse material at minute nanoscale to a magnification and detail that was not possible previously or on any other equipment within the institute.

Dr Adrian-Marie Philippe, a Senior Engineer at LIST who now works directly with TEM stated, “Thanks to this microscope we can analyse really tiny objects, so tiny that we were not able to see them before. This is important because here in the department, researchers are designing innovative materials and they are targeting materials that provide specific properties from an industrial standpoint”.

Unlike other microscopes that tend to have dedicated areas of analysis, TEM has the ability to examine any type of material whether it be biological, polymers, metallic, or composite materials, rendering its use applicable to a wide variety of fields and markets.

The first users of TEM is for LIST researchers at a fundamental research level as they fine tune the microscope which will result in it being beneficial for several research projects.

“What is also unique for LIST is that we are equipped with different complimentary techniques,” explained Dr Nathalie Valle Principal Investigator of the TEM mission in LIST. “In LIST we have also different specialists, and we can combine the different expertise just to understand materials. And we are not focused on one type of material, any kind of sample can be examined for accelerating our own and partner’s research impact”.

However, it is not as simple as placing materials under the microscope and examining them. Samples have to be prepared in a specific way and be thin enough for electrons to pass through them. Therefore, specific techniques must be implemented just to prepare the samples to be ready for examination.

The next step, planned for about a year from now, is to be able to open up the use to businesses and partners for the wide implications TEM use could have on an industrial level, and to this end several parties have already expressed interest in the technology.

As an example, Ceratizit, a Luxembourg-based company with international outreach specialised in producing sophisticated hard cutting materials for tools, has already worked with LIST in several projects. Now they are developing a special hard coating made up of different thin layers. TEM will help to examine each tiny layer individually to identify its characteristics.

The use of TEM, where virtually no material can’t be observed, means that the potential use for many sectors of industry is extremely wide-reaching.

Technical sheet

The JEOL’s microscope JEM-F200 allows recording images in Bright Field (BF), Dark Field (DF) and High Angle Annular Dark field (HAADF) modes. Crystalline properties are made accessible thanks to the acquisition of diffraction patterns in reciprocal space. In addition, the microscope is able to work in scanning mode (STEM) with the possibility, amongst other things, to perform chemical analysis by Energy-Dispersive X-ray Spectroscopy (EDS). More advanced chemical characterization will be achieved as well, thanks to Electron Energy-Loss Spectroscopy (EELS).

In terms of technical specifications, the microscope is equipped with a Cold-FEG gun providing a high brightness and a narrow energy spread, making it well suited for elemental mapping by EELS. The condenser part of the electronic column allows tuning both the probe size and its convergence angle independently, thanks to the embedded Quad-Lens technology. The double-tilt sample holder provides access to angles ranging from -25° to +25°. Finally, the Dual SDD detectors enable high sensitivity EDS measurements without shrinking the collection angle.

Some specifications in numbers:

• Accelerating voltage 80 and 200 kV
• Energy Spread (FWHM) : 0.3 eV
• Resolution (TEM only) : 0.23 nm
• Resolution (STEM-HAADF) : 0.16 nm
• Energy resolution (EDS) : 129eV
• Energy range (EELS) : 3000 eV
• Camera (RIO GATAN): 16 MPixel – 20 fps in full frame

Because TEM measurements often require a dedicated sample preparation, several techniques will be carried out by Asmaa El Moul, from LIST:

• Cryo-ultramicrotomy
• FIB lamella