- Andrea Severing: Dual nature of 5f electrons in URu2Si2 and isostructural compounds: from antiferro- to Pauli paramagnetism via the hidden order
- 11. 3. 2020, 14:10
- lecture room F2, first floor Ke Karlovu 5
- more information
Abstract:
We have carried out hard x-ray photoelectron spectroscopy (HAXPES) measurements at the U 4f core level and non-resonant inelastic x-ray scattering (NIXS) at the UO4,5 edges of UT2Si2 compounds that all form in the tetragonal ThCr2Si2 structure but exhibit different ground state properties: UFe2Si2 is a Pauli paramagnet; URu2Si2 is the famous hidden order compound of which the order parameter is still fiercely debated despite 30 years of intense experimental and theoretical studies; UPd2Si2 and UNi2Si2 are antiferromagnets with TN well above 100 K and sizeable ordered magnetic moments. We have determined the relative degree of the 5f-electron localization (HAXPES) as well as the symmetry of the 5f ground state wave function (NIXS) across these very different compounds. This enabled us to identify their systematics and to place them tentatively in an effectiveDoniach phase diagram.