Strain induced Jahn-Teller distortions in BaFeO3 : A first-principles study

TL;DR

This study uses first-principles calculations to show that tensile biaxial strain induces Jahn-Teller distortions in BaFeO3, revealing strain engineering as a way to modify its properties for technological applications.

Contribution

It demonstrates that tensile biaxial strain induces Jahn-Teller distortions in BaFeO3, a phenomenon not observed in similar compounds, using advanced DFT+U and hybrid functional methods.

Findings

Jahn-Teller distortion is induced under tensile biaxial strain.

Oxygen octahedra rotations and breathing are not observed.

Strained BaFeO3 exhibits unique properties compared to CaFeO3 and SrFeO3.

Abstract

The effect of epitaxial strain on structural, magnetic and electronic properties of BaFeO 3 per- ovskite oxide are investigated from first principles calculations, using the Density Functional The- ory (DFT) plus the Hubbard approach (DFT+U) within the Generalized Gradient Approximation (GGA). Hybrid functional calculations, based on mixed exact Hartree-Fock (HF) and DFT exchange energy functionals, are also performed. For the ground state calculations,the DFT+U is found more suitable to describe the half metallic and ferromagnetic state of cubic BaFeO 3 . The possible oc- curence of oxygen octahedra rotations, Jahn-Teller distortions and charge orderings through biaxial strain are explored. The obtained results reveal that the Jahn-teller distortion is induced under tensile biaxial strain while the oxygen octahedra rotations and breathing are unusualy not observed. Then, the strained BaFeO 3 is considered as a particular Jahn-Teller distorted perovskite with excep- tional properties when compared to CaFeO 3 and SrFeO 3 . These findings lead to a strain engineering of the JT distortions in BaFeO 3 , and thus for high fundamental and technological interests.