High energy-resolution set-up for Ir L3 edge RIXS experiments

Highlights: ► We recall the interest of studying low-energy excitations in correlated electron systems using RIXS. ► We present the setup for high-resolution RIXS experiments at the Ir L3 edge at the ESRF. ► We discuss how the present setup can be adapted for all other 5d and rare-earths. -- Abstract: High energy-resolution resonant inelastic X-ray scattering (RIXS) at the L2,3 edges of 3d transition metal compounds has proved to be a very powerful technique for the study of elementary excitations of various nature. In the case of cuprates, in particular, it was realized that magnetic excitations can be directly accessed, thus complementing neutron scattering experiments. It is clearly desirable to extend this technique to 5d transition metal compounds, whose L2,3 edges lie in the hard X-ray energy range. In the case of Ir, the L3 edge is found at 11.215 keV. To access excitations energies similar to those of magnetic excitations in cuprates, a resolving power better than ≈105 is needed. Here, we describe the hard X-ray RIXS set-up at the ID16 beam line at the European Synchrotron Radiation Facility (ESRF), suitable for L3 edge RIXS studies of Ir oxides, with a combined energy-resolution of 36 meV, i.e. a resolving power of 3 × 105