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 the description of the physical properties of correlated systems.
At the SEXTANTS beamline of the synchrotron SOLEIL, we perform RIXS experiments in the soft X-ray regime and, thanks to the novel MAGELEC sample environment, we now offer to the user community a globally unique configuration that opens new perspectives in the field of magnetic materials and operating devices through the possibility of performing RIXS under applied electric and magnetic fields.
After a short introduction on the RIXS technique, I will present our recent results obtained on La1-xSrxVO3. This material represents a canonical example of correlated system exhibiting a filling control metal-insulator transition, orbital ordering and antiferromagnetic transitions at low temperature. I will show how low-doping affects the local electronic structure primarily on the O sites, at odds with a simple Mott-Hubbard picture, and how orbital excitations are observed and gradually blueshift in the antiferromagnetic phase. I will discuss how these results can be partially explained by a purely local model using crystal field theory calculations.
I will then describe the capabilities of the MAGELEC sample environment. Its quadrupolar magnet delivers a rotatable magnetic field with a maximum strength of 0.45 T. The sample holder is equipped with 12 electrical contacts and works in a temperature range of 400K-18 K. I will present preliminary measurements on transition metal oxides where clear dichroic contrast is observable in the energy loss range corresponding to dd transitions, showing how magnetic circular dichroism RIXS experiments (RIXS-MCD) can go beyond the accuracy of the widely used X-ray magnetic circular
Source : Open Agenda