Studies concerning the electronic structure and the electron transfer in electron poor intermetallics

• Applicant: Dr. Oliver Janka
• Subject Area: Solid State and Surface Chemistry, Material Synthesis
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 441210509

The goal of the proposed project is the investigation of the bonding situation and the electron transfer in ternary alkali-, alkaline-earth, europium and ytterbium (M) aluminum intermetallics of the general composition MxTyAlz. This should be accomplished via quantum-chemical calculations along with additional spectroscopic investigations. The synthesis, the structural characterization as well as property (magnetism, electrical resistivity, heat capacity) and 151Eu Mößbauer spectroscopic investigations will be conducted in the group of Dr. Janka. Theoretical as well as NMR and XPS spectroscopy investigations will be performed in collaboration with the groups of Prof. Fokwa and Prof. Matar (both theory) as well as Prof. Eckert (NMR), Prof. Zacharias and Prof. Wittstock (both XPS). Systematic studies will be conducted on isostructural compound series, to obtain an insight with respect of the influence of the electron poor metal (M) and / or the transition metal T. Compounds known to literature as well as new materials obtained by exploratory research will be investigated and sorted into the broad context of intermetallic aluminum compounds. Besides the synthesis of phase-pure samples, also the knowledge of the structures of the respective compounds are essential. The structural parameters are crucial for theoretical calculations, which in turn are needed for the interpretation of the spectroscopic data. With respect to the NMR spectroscopic properties, compounds that exhibit more than one Al site are of interest, since this method allows to distinguish between the different crystallographic species (e.g. Ba3Pt4Al4). Knowing the crystal structure, geometric parameters and Bader charges, the observed signals can be attributed to the distinct crystallographic Al sites. Investigations via XPS help to understand the electronic situation. They allow for an interpretation of the electron transfer within these intermetallic materials and the comparison with novel compounds.

• DFG Programme: Research Grants
• International Connection: Lebanon, USA
• Cooperation Partners: Professor Dr. Boniface P. T. Fokwa; Professor Dr. Samir F. Matar