Strontium ferrite (Sr₂FeO₄) under pressure: Potential analog to strontium ruthenate (Sr₂RuO₄)

As an alternative platform to unravel some of the perplexing characteristics of strontium ruthenate, we propose to study the isostructural and more correlated material strontium ferrite. Using density functional theory combined with dynamical mean-field theory, we attribute the experimentally observed insulating behaviour at zero pressure to strong local electronic correlations generated by Mott and Hund's physics. At high pressure, our simulations reproduce the reported insulator-to-metal transition around 18 GPa. Along with distinctive features of a Hund metal, the resulting metallic state is found to display an electronic structure analogous to that of strontium ruthenate, suggesting that it could exhibit similar low-energy properties.