TUM: Kunkel, Fässler, Becherer
UofA: Hegmann, Mar
Students: Alexander Mutschke

Abstract:

Nowadays, a significant amount of research on hydrogenation reactions is carried out with regard to hydrogen storage materials and even hydridic lithium ion conductors. However, hydrogenation reactions can also be considered as a tool to design other materials. An example is the HDDR (hydrogenation-disproportionation-desorption-recombination) process, which is used to produce fine grained or even nanostructured highly coercive ferromagnetic materials based on rare earths, such as Nd₂Fe₁₄B or SmCo₅, where the hydrogen treatment eventually leads to a significant improvement of the magnetic properties. Furthermore, hydrogenation of Zintl phases leads to changes in the structure and properties, such as for instance the bandgap.

The project focuses on the synthesis of nanocrystalline semiconductor and thermoelectric materials via hydrogenation and subsequent dehydrogenation as well as the band gap tuning by (partial) hydrogenation of Zintl phases, clathrates and intermetallic phases. Primary characterization of new compounds will be performed by X-ray diffraction. Quantum-mechanical calculations will support the search for new hydrides and the electronic properties of these compounds will be modelled. Furthermore, the charge carriers’ mobility will be studied using Terahertz spectroscopy.