The structural, electronic, and magnetic properties of SrFeOn (n = 2 and 2.5): a GGA+U study

Using density-functional calculations within the generalized gradient approximation (GGA)+U framework, we investigate the structural, electronic, and magnetic properties of the ground states of SrFeOn (n = 2 and 2.5). The magnetism calculations show that the ground states of both SrFeO2 and SrFeO2.5 have G type antiferromagnetic ordering, with indirect band gaps of 0.89 and 0.79 eV, respectively. The electronic structure calculations demonstrate that Fe cations are in the high-spin state of (dz2)2 (dxz, dyz)2 (dxy)1(dx2–y2)1 (S = 2), unlike the previous prediction of (dxz, dyz)3 (dxy)1 (dz2)1 (dx2–y2)1 (S = 2) for SrFeO2, and in the high-spin state of (dxy, dxz, dyz, dx2–y2, z2)5 (S = 5/2) for SrFeO2.5.