Novel aspects and strong correlation in the electronic structure of Sr$_2$FeMoO$_6$

TL;DR

This study combines experimental and theoretical methods to explore the electronic structure of Sr$_2$FeMoO$_6$, revealing strong Coulomb correlations and spin-splitting effects that influence its magnetic properties.

Contribution

It provides new insights into the electronic correlations and spin phenomena in Sr$_2$FeMoO$_6$, combining photoemission spectroscopy with advanced calculations.

Findings

Strong Coulomb correlation effects in Fe 3$d$ and O 2$p$ states

Spin-splitting of O 2$p$ states of nonmagnetic origin

Implications for the stability of ferromagnetism

Abstract

We investigate the electronic structure of Sr$_2$FeMoO$_6$ combining photoemission spectroscopy with a wide range of photon energies and electronic structure calculations based on first-principle as well as model Hamiltonian approaches to reveal several interesting aspects. We find evidence for unusually strong Coulomb correlation effects both in the Fe 3$d$ and O 2$p$ states, with an enhanced manifestation in the majority spin channel. Additionally, O 2$p$ states exhibit a spin-splitting of nonmagnetic origin, which nevertheless is likely to have subtle influence on the stability of novel ferromagnetism of this compound.