Resonantsoft x-ray Raman scattering of NiO

Abstract

Resonant soft x-ray Raman scattering measurements on NiO havebeen made at photon energies across the Ni 2p absorptionedges. The details of the spectral features are identified asRaman scattering due to d-d and charge-transfer excitations.The spectra are interpreted within the single-impurity Andersonmodel, including multiplets, crystal-field and charge-transfereffects. At threshold excitation, the spectral featuresconsists of triplet-triplet and triplet-singlet transitions ofthe 3d8 configuration. For excitation energiescorresponding to the charge-transfer region in the Ni 2px-ray absorption spectrum of NiO, the emission spectra areinstead dominated by charge-transfer transitions to the3d9\\underline L-1 final state. Comparisons of the finalstates with other spectroscopical techniques are also made.