First principles density functional+U pseudopotential study on the electronic structure of layered perovskite LaSr3Fe3O10

Abstract

The electronic, magnetic and crystal structures of layered perovskite oxide LaSr3Fe3O10 (LSFO) in the Ruddlesden-Popper structure were studied from first principles using the density functional theory (DFT)+U pseudopotential (PP) method and a self-consistent constrained DFT technique (Hamada and Ohno 2019 J. Phys.: Condens. Matter 31 065501). Using this technique, the magnetic structure of LSFO was determined to be antiferromagnetic and an effective Hubbard on-site interaction parameter for Fe 3d electrons, Ueff(Fe3d) = 6.08 eV was identified for LSFO. The DFT+U PP calculations of LSFO models using this Ueff(Fe3d) value reproduced the experimentally observed metallic characteristics and crystal structure of LSFO, demonstrating the correct determination of the Ueff(Fe3d) value of the large and complex LSFO material. The first-principles DFT+U calculation of large and complex strongly-correlated systems was enabled using the self-consistent constrained DFT technique.