If you want to conduct world-class materials research today, you won't get far with an optical microscope. For years, TU Wien has been conducting very successful research into new materials that are needed in many technological areas - from microelectronics to new energy technology relevant to climate protection.

TU Wien has its own University Service Centre for Electron Microscopy (USTEM). ‘Different questions from materials research can be answered with different devices,’ says USTEM Director Prof Johannes Bernardi. ‘Depending on which material samples you want to analyse, which properties of the sample you want to measure or whether the sample needs to be processed in a targeted manner, you need different technologies. We at the USTEM therefore work hand in hand with research teams from several faculties in order to optimise scientific quality.’

A range of state-of-the-art imaging infrastructure is now being joined by a further device: the Helios Hydra UX DualBeam System from ThermoFisher Scientific - a combination of scanning electron microscope and ion beam device. The new hybrid device consisting of a scanning electron microscope and ion beam device will be set up and installed over the next few months.

Materials for the energy transition

The new device, which is jointly funded by the Austrian Science Fund FWF and TU Wien, will play an important role in the Cluster of Excellence MECS - MATERIALS FOR ENERGY CONVERSION AND STORAGE, opens an external URL in a new window, in which Prof Günther Rupprechter and an international team at TU Wien and partner institutions are researching materials for the energy transition. This involves, for example, catalysts that can be used to produce hydrogen and break down carbon dioxide, thereby converting it into valuable product materials.

Electron and ion beam in one

Scanning electron microscopes can be used to image the surface structure of samples with a resolution in the nanometre range. A precisely focussed beam of electrons is shot at a specific point on the sample. This can produce a whole range of physical effects: The electrons can be scattered, they can dislodge other electrons from the sample, they can generate radiation when they collide with the sample - all of which can be recorded using suitable detectors. This not only makes it possible to find out exactly which elements the sample consists of, but also the crystallographic structure in which they are arranged.

‘The new device that we are building at TU Wien has such an electron beam. However, it also offers the option of using a focussed ion beam to process materials in a targeted manner - and with very different ions. We can work with xenon, argon, oxygen or even nitrogen,’ explains Bernardi.

In contrast to the electron beam, which usually does not change the sample, the ion beam can shoot out atoms from the sample and thus manipulate the surface of the sample in a targeted manner. ‘For example, we can use it to make targeted cuts and not only measure the uppermost atomic layers of the sample, but also learn something about the layers underneath. This provides important additional information to our other characterisation methods in the COE MECS,’ says Rupprechter.

Fields of application

The new system combines several advantages: The ion beam has a particularly high material removal rate, while the electron beam enables a particularly high resolution. This combination makes it possible to obtain 3D information on the finest structural details - and from significantly larger sample areas than would be possible with a conventional device.

The new device also enables the production of ultra-thin lamellae, which can then be analysed using a transmission electron microscope. Another important feature is an airlock system that enables the examination of samples that are sensitive to air: Using the airlocks, such samples can be placed in a vacuum, or in a special atmosphere of non-reactive gas. The facility is also equipped with a comprehensive analytical system for chemical X-ray microanalysis and structural determinations.

To ensure a long-term sustainable investment, it is important to equip such high-performance devices with the optimum peripherals, e.g. modules for analytics. The use of these modules is made possible by funding from the TU Wien Foundation. ‘I am delighted that we as a foundation have been able to make an effective contribution to the purchase of this high-end equipment in line with our motto “Science for a better world”,’ says Elfriede Baumann, Chairwoman of the Foundation Board.

Contact

Prof. Johannes Bernardi
USTEM
Technische Universität Wien
+43 1 58801 45210
johannes.bernardi@tuwien.ac.at

Prof. Günther Rupprechter
Institut für Materialchemie | COE MECS Director of Research
Technische Universität Wien
+43 1 58801 16500
guenther.rupprechter@tuwien.ac.at