Hybridization Effect in BaFe2(As1−xPx)2 Observed by Hard X-ray Photoemission Spectroscopy

Hard X-ray photoemission studies are carried out to evaluate the electronic structure of iron-based superconductors BaFe2(As1−xPx)2 in a wide range of the P content 0 ≤ x ≤ 0.61. As x increases, the Fe 2p3/2 and Ba 3d5/2 core levels linearly shift to the higher and lower binding energy sides, respectively, while the anion core levels show no appreciable shifts. These results can be explained in terms of the Madelung potential and the change of the hybridization between the Fe 3d and the anion orbitals. The increase of the hybridization with x leads to an increase of the band width, which is consistent with the spectrum shift near the Fermi level.