Doping dependence of Ni 2p x-ray-absorption spectra of MxNi1−xO (M=Li,Na)

Abstract

In this paper we give a description of the doping dependence of the $\mathrm{Ni} 2p$ x-ray-absorption spectra of $M_x{\mathrm{Ni}}_{1-x}\mathrm{O}$ ($M=\mathrm{L}\mathrm{i},\mathrm{N}\mathrm{a}$). We will show that a description beyond an atomic-multiplet calculation is required. To study intermediate doping levels use will be made of a two-metal-site cluster, where one side functions as a hole reservoir. From this study it follows that holes are most likely on the oxygen atoms of the ${\mathrm{NiO}}_6$ units around the Li impurities.