The electronic structure of mesoscopic NiO particles

The electronic structure of mesoscopic NiO particles was studied by means of soft X-ray absorption spectroscopy. The Ni 2p spectra show convincingly that the changes in the electronic structure of mesoscopic NiO do not involve Ni3+ as previously thought. The O 1s spectra show that the minority Ni eg band is split by crystal field distortions related to defects and the large surface-to-volume ratio in this material. Other effects in the spectra, minor changes and extra broadening, are attributed to lattice disorder.