L. Lin

Soft-x-ray spectroscopy measurements of the p-like density of states of B in MgB[d2] and evidence for surface boron oxides on exposed surfaces - art no. 132504

Soft-x-ray absorption and fluorescence measurements are reported for the K edge of B in MgB{sub 2}. The measurements confirm a high density of B p{sub xy}({sigma}) states at the Fermi edge and extending to approximately 0.9 eV above the edge. A strong resonance is observed in elastic scattering through a core exciton derived from out-of-plane p{sub z}({pi}{sup *}) states. Another strong resonance, observed in both elastic and inelastic spectra, is identified as a product of surface boron oxides.

Electron correlation effects in resonant inelastic X-ray scattering of NaV2O5.

Element- and site-specific resonant inelastic x-ray scattering spectroscopy (RIXS) is employed to investigate electron correlation effects in NaV2O5. In contrast to single photon techniques, RIXS at the vanadium L3 edge is able to probe d-d* transitions between V d-bands. A sharp energy loss feature is observed at -1.56 eV, which is well reproduced by a model calculation including correlation effects. The calculation identifies the loss feature as excitation between the lower and upper Hubbard bands and permits an accurate determination of the Hubbard interaction term U = 3.0 +/- 0.2 eV.