Spin polarized density functional theory calculations of the electronic structure and magnetism of the 112 type iron pnictide compound $$\hbox {EuFeAs}_2$$

Abstract

Using density-functional theory, we investigate the electronic, magnetic, and hyperfine-interaction properties of the 112-type iron-pnictide compound $${\hbox {EuFeAs}}_2$$ EuFeAs 2 , which is isostructural to the high-temperature iron-based superconductor $${\hbox {Ca}}_{1-x}{\hbox {La}}_x{\hbox {FeAs}}_2$$ Ca 1 - x La x FeAs 2 . We show that the band structure of $${\hbox {EuFeAs}}_2$$ EuFeAs 2 is similar to that of the 112-type compounds’ family, with hole-like and electron-like bands at the Brillouin-zone center and corners, respectively. We demonstrate that the bands near the Fermi level originate mainly from the Fe atoms. The presence of a mixture of ionic and covalent bonding is predicted from the charge-density and atom-resolved density-of-states calculations. There is good agreement between the calculated hyperfine-interaction parameters with those obtained from the $$^{57}$$ 57 Fe and $$^{151}$$ 151 Eu Mössbauer measurements. The spatial distribution of atoms in $${\hbox {EuFeAs}}_2$$ EuFeAs 2 leads to an in-plane 2D magnetism. Moreover, ab-initio calculations predict the compound’s magnetic moment and the magnetic moments of each constituent atom. Also, the density of states profile provides insight into the relative magnitude of these moments. Electronic structure calculations and Fermi surface topology reveal various physical and chemical properties of $${\hbox {EuFeAs}}_2$$ EuFeAs 2 . Valence electron density maps indicate the co-existence of a wide range of chemical bonds in this system, and based on structural properties, the transport characteristics are deduced and discussed. A thorough analysis of the atomic structure of $${\hbox {EuFeAs}}_2$$ EuFeAs 2 and its role in the bond formation is presented.

Structural, Elastic, Electronic, Magnetic, and Thermoelectric Characteristics of MgEu2X4 (X = S, Se) Spinel Compounds: Ab‐Initio Calculations

“…Combined with the value of 0.59 Ry for the Hubbard parameter, it leads to the effective Hubbard potential of 0.549 Ry (7.48 eV) for both compounds. [ 25 ]…”

“…Combined with the value of 0.59 Ry for the Hubbard parameter, it leads to the effective Hubbard potential of 0.549 Ry (7.48 eV) for both compounds. [25] The wave-function expansion inside the atomic spheres has a maximum quantum number of l max ¼ 10. For the expansion of wavefunctions in the interstitial area, the core cutoff energy of 81.66 eV, and the plane wave cutoff K max ¼ 8=R mt are used (R mt is the lowest muffin-tin radius in the unit cell, and K max is the magnitude of the biggest K vector in the plane-wave expansion).…”

Iron-arsenide monolayers as an anode material for lithium-ion batteries: a first-principles study

“…Additionally, empirical tuning of the on-site U interaction could be done to better agree with experimental data for the geometries, band structures, and redox energies in compounds containing Fe. 49,50 However, when it comes to proposing novel structures theoretically, the linear response approach (LRA) emerges as a good choice for determining U accurately. To choose the appropriate U for our structures, the linear-response technique has been used by Cococcioni et al 51 The details of this calculation have been elaborated in the ESI.…”