Superconductivity and electronic properties of y-U alloys and their hydrides

Title: Superconductivity and electronic properties of γ-U alloys and their hydrides. Author: Ilya Tkach Department / Institute: Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University Supervisor of the doctoral thesis: Doc. RNDr. Ladislav Havela, CSc., Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Prague, The Czech Republic Abstract: Low-temperature electronic properties for U-Mo and U-Zr splats stabilized in γ-U were investigated. Magnetic measurements revealed Pauli paramagnetic behavior with temperature independent susceptibility for U-Mo alloys. U-Mo and U- Zr splats become superconducting at low temperatures with Tc up to 2.1 K and critical field 5-6 T. The superconductivity of -U can be considered as a bulk effect and can be described by the BCS theory, while -U superconductivity is not a real bulk effect. U-Mo and U-Zr alloys absorb hydrogen at high pressures (p ≥ 4.5 bar) and form hydrides with stoichiometry analogous to UH3. The hydrides with Mo have an amorphous structure based on β-UH3 phase, while hydrides with Zr have a crystalline structure of the -UH3 type. (UH3)1-xMox hydrides are ferromagnetic with enhanced TC up to 202 K and magnetic moments 1.1 μB/U in comparison with pure β-UH3 (175 K; 0.87 μB/U)...