Resonant Raman scattering in Nd2O3 and the electronic structure of Sr2RuO4 studied by synchrotron radiation excitation Original Research Article

This paper is intended to illustrate two points. The first is the extensive growth of resonant Raman soft X-ray scattering due to the emergence of third-generation X-ray sources. With these sources, the ubiquitous presence of Raman scattering near the 3d and 4d ionization thresholds has been used to elucidate the excitation process in a number of rare earth and transition metal compounds. Such scattering can produce dramatic changes in the emission spectrum, as we show in our example of inelastic scattering at the 3d threshold of Nd2O3. Photon-in photon-out soft X-ray spectroscopy is adding a new dimension to soft X-ray spectroscopy by providing many opportunities for exciting research, especially at third-generation synchrotron light sources. Second, it is very effective to use theory and experiment to characterize the electronic properties of materials. In particular we confirmed in-plane oxygen–ruthenium bonding in Sr2RuO4, the first copperless perovskite superconductor, by analyses using calculations, soft X-ray emission spectroscopy (SXE) and photoelectron spectroscopy (PES). Measurements of this type illustrate the importance of combining SXE and PES measurements with theoretical calculations.