Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette,France
22/03/2022/ at 11:00h
Institute of Physics, lecture room 1st wing and Zoom
Resonant inelastic X-ray scattering (RIXS) is a photon-in photon-out technique in which the system is resonantly excited at an absorption edge and the scattered photons are measured in order to probe the energy and momentum transfer of the intrinsic excitations, such as electronic, magnetic or of the lattice. This spectroscopy has been subject of a remarkable progress in the last decades for its capability of gaining information of fundamental interest for correlated systems.
At the SEXTANTS beamline of the synchrotron SOLEIL, we perform RIXS experiments in the soft X-ray regime. After a short presentation of the technique, I will highlight some of the main experimental results we recently obtained. One example is represented by the work on La1-xSrxVO3, a canonical example of correlated system exhibiting a filling control metal-insulator transition, as well as orbital and antiferromagnetic orderings at low temperature. I will show how low-doping (x=0.1) affects the electronic structure primarily on the O sites, at odds with a simple Mott-Hubbard picture, and how RIXS can measure orbital excitations and their behavior with temperature. I will discuss how these results can be only partially understood by a local model based on crystal field theory calculations.
Finally, I will describe the capabilities of the novel MAGELEC sample environment, which was conceived for performing RIXS experiments under electric and magnetic fields in a temperature range from 400 K down to 18 K. MAGELEC consists of sample holder equipped with 12 electrical contacts, which is combined with a compact quadrupolar magnet delivering a rotatable magnetic field up to 0.45 T. Thanks to the particular design of the electromagnet, the whole scattering plane is available for magnetic circular and linear dichroism RIXS experiments. I will show how this unique sample environment, accessible for external users since February 2020, opens new perspectives at the SEXTANTS beamline thanks to the possibility to tackle several kinds of open questions in the field of transition metal compounds beyond the accuracy obtained by the widely used X-ray magnetic circular dichroism and in operando conditions.