Electronic structure of BaFe₂As₂ as obtained from DFT/ASW first‐principles calculations

Abstract

We use ab-initio calculations based on the augmented spherical wave method within density functional theory to study the magnetic ordering and Fermi surface of BaFe2As2, the parent compound of the hole-doped iron pnictide superconductors (K,Ba)Fe2As2, for the tetragonal I4/mmm as well as the orthorhombic F mmm structure. In comparison to full potential linear augmented plane wave calculations, we obtain significantly smaller magnetic energies. This finding is remarkable, since the augmented spherical wave method, in general, is known for a most reliable description of magnetism.

Charge transfer effects on the Fermi surface of Ba0.5K0.5Fe2As2

“…The calculations are performed using the full-potential linearized augmented plane-wave plus local orbitals (FP-LAPW+lo) scheme implemented in the WIEN2k package [27]. As compared to other schemes, this method seems to provide a reliable description of BaFe 2 As 2 compounds [15]. The exchange-correlation potential is treated in the local density approximation [28].…”

“…In the case of the iron pnictides the As position particularly influences the magnetic coupling between the Fe atoms. For AFe 2 As 2 with A = Ca, Sr, Ba, Eu [11][12][13][14][15][16] the interaction along the crystallographic c-axis is found to be one order of magnitude weaker than the corresponding intra-planar interaction [17]. In contrast, in RO 1−x F x FeAs, where R represents a rare-earth ion, the inter-planar interactions are much weaker [1][2][3][4][5][6].…”