- Michal Falkowski: Electron and thermal transport properties of the strongly correlated Laves phase UTi2Hx
- 21. 3. 2018, 14:30
- lecture room F2, first floor Ke Karlovu 5
- more information
Abstract:
Electronic structure of uranium compounds can vary dramatically. The main factors that influence it are the smallest distance between uranium atoms, determining the overlap of the 5f states, and the 5f ligand hybridization. An efficient way of tuning is hydrogen absorption, which expands the crystal lattice. Unfortunately the hydrides are typically obtained in the form of fine powder, which makes some experiments (e.g. transport) difficult.
In the context of hydrogenation study of U-Ti alloys, we succeeded to synthesize a cubic uranium Laves phase UTi2Hx, which does not exist without hydrogen. This group of Laves phase hydrides can absorb a variable amount of hydrogen. Such situation, albeit rare, was observed already before, for example at the ThZr2Hx system, which allowed to vary the H concentration is a wide concentration range x = 1.8-6.7 [1]. The first indication that U and Ti can form a Laves phase in the presence of hydrogen appeared in [2].
During my talk I will try to emphasize the most important experimental findings of UTi2Hx compound, with special attention on the electron and thermal transport properties (electrical resistivity, thermoelectric power and thermal conductivity). To the best of our knowledge this are the first results which concern the attempt of measurements of the heat conduction and thermoelectric properties of U-Ti hydride obtained in the stable (bulk) form.
References:
[1] W. Bartscher, J. Rebizant, J.M. Haschke, J. Less Common Met. 136 (1988) 385-394.
[2] T. Yamamoto, M. Teshigawara, H. Kayano, N. Minakawa, S. Funahashi, J. Alloys Compd. 224 (1995) 36-38.