First-principles study of the transition metal-doped iron-based superconductor AFe2As2 (A = Ba, Sr)

Abstract

The characteristics of structural changes, Fe magnetic moment and electronic structure of TM (TM = Co, Ni, Rh, Pd, Ir and Pt)-doped AFe 2 As 2 (A = Ba, Sr) were studied by first-principles calculations. After the introduction of the dopants, almost all the Fe-Fe distances become longer. The nesting between the electron pockets and the hole pockets is formed. The Fermi level has a tendency to move from the hole band to the electron band. With the decrease in Fe magnetic moment, the width of Fe 3d and As 4p hybridized bands is increased, which is considered to be the decrease in electronic localized character and the increase in itinerary. The observed common features in our calculations provide information on the generation of superconductivity in iron-based superconductors AFe 2 As 2 (A = Ba, Sr).

The role of As ions height in AFe2As2 (A = Ba, Sr)

“…Kang et al 19 found in 2020 that the As-Fe-As bond angle in BaFe 2 As 2 can induce superconductivity when it is close to the regular tetrahedron. Li et al 20,21 proposed in 2022 that the Fe-Fe distance is closely related to the AFM suppression as well as the Fe-As bond length in the doping and pressure environment of AFe 2 As 2 (A = Ba, Sr).…”