Scientific Internships

The following topical areas can serve as the basis for scientific internships on the level of a Masters thesis or comparable internships. If you are interested in more details, contact us at r.bliem@arcnl.nl.

Resolving surface reactions in plasma

Most chemical reactions require the activation of reactants to process. In catalytic reactions, reactive surfaces help with this activation. Nevertheless, often high temperatures are needed for reactions involving highly stable molecules, such as N₂ or CO₂. A fast alternative to heating up a large reactor is directly activating the molecules in a plasma discharge to overcome the initial energy barriers already at lower catalyst temperatures. The surface processes during the interaction of reactive materials with plasmas are, however, not well understood. In this project, you will use photoelectron spectroscopy to analyze catalytically active surfaces exposed to plasma. On the example of plasma-assisted NH₃ synthesis from N₂ and H₂, you will study the surface chemistry and composition live during plasma exposure. You will draw conclusions on the role of the catalyst and the rate-limiting steps of plasma-assisted reactions and compare them to the processes currently used in industry.

High-entropy materials in the ultra-thin limit

High-entropy materials are compounds with five or more principal elements and received their name based on the high configurational entropy of the resulting mixture. While this sounds not very different from a regular complex alloy, the high entropy has been found to introduce exceptional properties, such as increasing ductility at low temperature, remarkable mechanical strength or even superconductivity. In this project you will study the properties of high-entropy materials on the nanoscale. You will grow thin films of a high entropy alloy or ceramic of different thicknesses down to a few nanometers using pulsed laser deposition. The structural, mechanical, and chemical properties of the films at different thicknesses will allow for conclusions on the role of entropy effects and their breakdown. For this purpose, the surface and interface properties of the materials will be analyzed using a variety of surface science techniques: X-ray photoelectron spectroscopy, electron microscopy, scanning probe microscopy, and several more.

Understanding laser damage in the first monolayers of a solid

High-power lasers are essential to applications from laser cutting to nanolithography. Exposure to high light intensities is known to cause changes in materials, ranging from mild heating and defect mobility to local plasma formation and violent removal of material. The atmosphere, in which the interaction of light and matter takes place, is expected to play an important role in the modifications of the materials. In particular the material properties in the surface region are highly sensitive to processes such as segregation or oxidation. In this project, you will use a high-intensity nanosecond laser to expose atomically defined surfaces to light pulses close to the damage threshold of the material. You will use photoelectron spectroscopy to analyze the composition and surface chemistry of the outermost nanometers of the solid before and after exposure to laser pulses. A comparison of the light-induced changes in ultra-high vacuum and in well-defined oxygen pressures will allow you to determine the key ingredients to laser-induced damage in the first few monolayers of solids.