Localized Electronic Excitations in NiO Studied with Resonant Inelastic X-Ray Scattering at the NiMThreshold: Evidence of Spin Flip

We studied the neutral electronic excitations of NiO localized at the Ni sites by measuring the resonant inelastic x-ray scattering (RIXS) spectra at the Ni $M_{2,3}$ edges. The good energy resolution allows an unambiguous identification of several spectral features due to $dd$ excitations. The dependence of the RIXS spectra on the excitation energy gives evidence of local spin flip and yields a value of $125\pm 15\mathrm{meV}$ for the antiferromagnetic exchange interaction. Accurate crystal field parameters are also obtained.