Dynamical Mean-Field Approach to Ni 2p X-ray Photoemission Spectra of NiO: A Role of Antiferromagnetic Ordering

Abstract

The Ni \(2p\) X-ray photoemission spectra of NiO are investigated using a \(dp\) model, simulating a Ni \(3d_{e_{g}}\) and O \(2p\) electron system, within a dynamical mean-field approximation. By combining a tight-binding band calculation with a degenerate impurity Anderson model, the rock-salt-type crystal structure and a local \(d\)–\(d\) Coulombic multiplet coupling are considered in the calculation. A characteristic partial density of states is obtained for type II antiferromagnetic phase. A double-peak structure of the Ni \(2p_{3/2}\) main line is excellently reproduced by the calculation. In addition to the nonlocal screening accompanied by a Zhang–Rice doublet formation, the antiferromagnetic ordering plays a crucial role in the formation of the double peaks. The sensitivity of the main-line shape to the optimized hybridization function is emphasized. The lowest first-ionization state is given by electron removal from the Zhang–Rice doublet band.