First-Principle Simulation of Ferromagnetism in Gd-Doped Mg₂X (X=Si, Ge and Sn)

Abstract

Magnetic phase stability and electronic properties of Gd-doped Mg2X ([Formula: see text], Ge and Sn) were investigated by first-principle calculations based on density functional theory. The present calculations were performed using the Generalized Gradient Approximation (PBE-GGA) and the modified Becke–Johnson (mBJ-GGA). The 4[Formula: see text] electrons’ behavior has been investigated as a function of the Coulomb repulsion [Formula: see text] by varying it from 0[Formula: see text]eV to 8[Formula: see text]eV. The ground state properties for the pure compounds are consistent with experimental values and other theoretical data. All doped compounds are metallic and ferromagnetic with large Curie temperature values. It was found that both exchange potentials ([Formula: see text] and [Formula: see text]) provide a better description of the electronic structures of pure and doped systems than regular GGA and mBJ.

Magnetic Properties of 3d Transition Metal Atoms (V, Cr, Mn, Fe, Co, or Ni)‐Doped Mg2Si

“…The reported experimental bandgap of Mg 2 Si is 0.78 eV [ 19 ] while our computed value is 0.22 eV, which is in agreement with the computed results by Ahmar. [ 21 ] The lower computed value is known to be due to generalized gradient approximation (GGA) underestimating the bandgap value.…”

“…[ 17,18 ] Undoped Mg 2 Si is well known as a nonmagnetic semiconductor. [ 19 ] However, as far as we know, there are few studies on the magnetic properties of doped Mg 2 Si, except for Kim, [ 20 ] Vikram, [ 17 ] Ahmar, [ 21 ] and our group. [ 22 ]…”

“…[ 17 ] Ahmar et al investigated the magnetic phase stability and electronic properties of Gd‐doped Mg 2 Si by first‐principle calculations, and the results show that the Gd‐doped Mg 2 Si are FM and metallic. [ 21 ] We previously calculated that when a single neutral Fe atom was doped into the Mg 2 Si lattice, Fe was expected to be located at the Mg site preferentially, and the local magnetic moment of Fe was 1.38 . [ 22 ] The result indicated the local magnetic moments are available by doping with magnetic dopants.…”

“…[17,18] Undoped Mg 2 Si is well known as a nonmagnetic semiconductor. [19] However, as far as we know, there are few studies on the magnetic properties of doped Mg 2 Si, except for Kim, [20] Vikram, [17] Ahmar, [21] and our group. [22] Experimentally, Kim et al reported that single crystals of Mn-doped Mg 2 Si with various Mn contents were prepared, and magnetic properties were investigated.…”

Machine-learned model Hamiltonian and strength of spin-orbit interaction in strained Mg2X (X = Si, Ge, Sn, Pb)

“…[20][21][22][23][24][25][26][27] An intensive theoretical study has so far been performed on these compounds, mainly using density functional theory (DFT). [1,14,15,[28][29][30][31] The theoretical studies can provide deep and independent insight into the physics of these compositions and shed light on delicate aspects. For example, one can attain better view over the physical mechanisms and possibly harnessing them in the future experiments, to create new opportunities, achieve more reliable analysis, and avoid introducing detrimental effects during the implementation process.…”