Abstract
Continued improvement of the energy resolution of resonant inelastic x-ray scattering (RIXS) spectrometers is crucial for fulfilling the potential of this technique in the study of electron dynamics in materials of fundamental and technological importance. In particular, RIXS is the only alternative tool to inelastic neutron scattering capable of providing fully momentum resolved information on dynamic spin structures of magnetic materials, but is limited to systems whose magnetic excitation energy scales are comparable to the energy resolution. The state-of-the-art spherical diced crystal analyzer optics provides energy resolution as good as 25 meV but has already reached its theoretical limit. Here, we demonstrate a novel sub-10 meV RIXS spectrometer based on flat-crystal optics at the Ir-L3 absorption edge (11.215 keV) that achieves an analyzer energy resolution of 3.9 meV, very close to the theoretical value of 3.7 meV. In addition, the new spectrometer allows efficient polarization analysis without loss of energy resolution. The performance of the instrument is demonstrated using longitudinal acoustical and optical phonons in diamond, and magnon in Sr3Ir2O7. The novel sub-10 meV RIXS spectrometer thus provides a window into magnetic materials with small energy scales.
Highlights
The description of strongly correlated electron systems by means of elementary excitations has been a useful concept in modern condensed-matter physics[1]
Flat-crystal x-ray optics are superior in performance to curved crystal systems, because they are free from figure errors and strains that degrade the performance[18,19,20,21,22]
In order to assess the performance of the CA-analyzer, static diffraction characteristics as well as dynamic rocking curves and energy scans were extensively simulated
Summary
The description of strongly correlated electron systems by means of elementary excitations has been a useful concept in modern condensed-matter physics[1]. It is a recent finding that resonant inelastic x-ray scattering (RIXS) can probe magnons as a result of the core-hole spin-orbit coupling of transition metal L-edges[2,3]. RIXS is routinely used to measure magnetic excitations in various different types of materials including cuprates[4], iridates[5,6,7] and osmates[8], with the highest energy resolution being ~25 meV at the Ir L3 absorption edge[7,9]. The x-ray optics of state-of-the-art, high-resolution RIXS spectrometers are based on diced, spherical crystal analyzers in a near back-scattering geometry[13,14,15]. A novel RIXS spectrometer with sub-10 meV energy resolution at the Ir L3 edge is introduced, based on flat-quartz crystal optics[18]. Recent advances in multilayer optics provide a way to overcome this impediment[23,24,25,26] through the use of curved, laterally-graded mirrors (called Montel mirror) that can accept radiations in a large solid angle
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
