Electronic and magnetic properties of YBa2Fe3O8 from a first-principles study

The electronic and magnetic properties of Y Ba2Fe3O8 have been systematically investigated within the framework of density-functional theory using the standard generalized gradient approximation (GGA) as well as the GGA plus Hubbard U ( GGA + U ) method. The GGA results show that the G-type antiferromagnetic (AFM) state is preferred among the considered magnetic configurations. The striking ionic character is shown for Y and Ba atoms while very strong hybridization is found between Fe 3d and O 2p orbitals. Furthermore, the Fe–O–Fe superexchange interaction should be responsible for the stability of the AFM magnetic structure in this case. In addition, our theoretical calculations reveal that the ground state of Y Ba2Fe3O8 is a strongly correlated charge-transfer insulator with a finite band gap above the Fermi level obtained by the GGA + U scheme, which is in agreement with the experimental observations.