Electronic structure of Pr2MnNiO6 from x-ray photoemission, absorption and density functional theory

TL;DR

This study investigates the electronic structure of Pr2MnNiO6 using spectroscopy and density functional theory, revealing charge states, covalent interactions, and a band gap consistent with theoretical calculations.

Contribution

It provides a detailed analysis of the charge transfer and covalent nature of Pr2MnNiO6 using combined experimental and theoretical methods.

Findings

Mn is in 2+ state, Ni in 4+ state.

Band gap of 0.9 eV observed and calculated.

Strong p-d charge transfer character identified.

Abstract

The electronic structure of double perovskite Pr2MnNiO6 is studied using core x-ray photoelectron spectroscopy and x-ray absorption spectroscopy. The 2p x-ray absorption spectra show that Mn and Ni are in 2+ and 4+ states respectively. Using charge transfer multiplet analysis of Ni and Mn 2p XPS spectra, we find charge transfer energies {\Delta} of 3.5 and 2.5 eV for Ni and Mn respectively. The ground state of Ni2+ and Mn4+ reveal a higher d electron count of 8.21 and 3.38 respectively as compared to the atomic values of 8.00 and 3.00 respectively thereby indicating the covalent nature of the system. The O 1s edge absorption spectra reveal a band gap of 0.9 eV which is comparable to the value obtained from first principle calculations for U-J >= 2 eV. The density of states clearly reveal a strong p-d type charge transfer character of the system, with band gap proportional to average charge transfer energy of Ni2+ and Mn4+ ions.