PIER Photon Science Colloquium: Probing atomic orbitals in heavy-fermion compounds with X-rays

by Andrea Severing (Universität zu Köln)

Friday 31 Oct 2014, 15:00 → 16:00 Europe/Berlin

CFEL, Bldg. 99 (DESY Hamburg)

Heavy Fermion compounds are rare earth or actinide based materials comprising unconventional superconductors, insulators or antiferromagnets. In the last decade these materials attracted a lot of interest due to the discovery that intermetallic antiferromagnets can be tuned through a quantum phase transition into a Heavy Fermion state by modifying external parameters. Here the hybridization of the localized f electrons with the conduction electrons is intimately linked to the ground state properties so that the detailed knowledge of the f orbitals involved is of great importance, in particular because these orbitals are highly anisotropic and their occupation cannot be calculated ab-initio. We introduced well established and new X-ray techniques to this field of research which was traditionally occupied by neutron scattering. Soft X-ray absorption at the rare earth M-edge and non resonant inelastic X-ray scattering at the N-edge are our methods of choice and examples will be presented.