Study on the magnetic origin in p-type ferromagnetic semiconductor (Ga,Fe)Sb: ab initio calculations

Abstract

The electronic and magnetic properties of Ga1−xFexSb (x = 0.125, 0.25, 0.5) have been investigated using the first-principles calculations based on density functional theory (DFT) and DFT plus on-site repulsion scheme (DFT+U). We found that the Coulomb U parameter plays an important role in predicting the correct stable magnetic order. Using the DFT+U method, the ferromagnetic (FM) ordering is found to be the magnetic ground state for both concentrations 12.5% and 25%, where the DFT failed without on-site repulsion U-term correction. This failure of semi-local DFT functionals is the fingerprint of the correlated nature of Fe-3d electrons. This result is in good agreement with experiment. Increasing Fe concentration up to 50% changing the magnetic ground state from FM to antiferromagnetic (AF) phase. We have used the Heyd-Scuseria-Ernzerhof (HSE) method to calculate the unfolded band structure of supercell for Ga1−xFexSb for x = 0.125, in both FM and AF phases. The location of Fe-3d states in the calculation of the unfolded band structure showed a good accordance with recent resonance photoemission spectroscopy (RPES) experimental results. We have found that hole carriers have an important role at Fermi level E F . The rules of thumb to predict the stability of the ferromagnetism in Fe doped GaSb FMS have been discussed.

Computational investigation of high Curie temperature in a new N‐type ferromagnetic diluted magnetic semiconductors, especially iron‐doped on GaSb

“…; 𝑘 𝐵 = 0.08625𝑚𝑒𝑉∕𝐾; 𝜇 𝐵 = 5.49 × 10 −23 𝐽∕𝑇; Fe ion concentration x = 3.9%−20%; and the n ≈ 5 × 10 26 𝑚 −3 . [3,28,35,37,38,44,[63][64][65][66]69,72,73,75,76] F I G U R E 2 Specific heat capacity versus temperature with a constant x = 0.2.…”

“…In this part, we have used the essential parameters to drown the graph of ferromagnetic diluted magnetic semiconductor that are calculated in the above; coupling exchange interaction Fe‐Fe energy of (Ga,Fe)Sb $${J}_{nm} = 10meV$$; the lattice constant of (Ga, Fe)Sb $$a = 6.09{A}^o$$; atom $$S = \frac{5}{2}$$; $${k}_B = 0.08625meV/K$$; $${\mu }_B = 5.49 \times {10}^{ - 23}J/T$$; Fe ion concentration x = 3.9%−20%; and the n $$ \approx 5 \times {10}^{26}{m}^{ - 3}$$. [ 3,28,35,37,38,44,63–66,69,72,73,75,76 ]…”

“…This indicates that this work is novel compared to prior studies and more applicable for spintronic devices than other developments. The total spin quantum of Fe 3 + is S = 2.5, Fe ion concentration from 13.9% to 20%, a = 6.09$${A}^0$$, and n = × $${10}^{18}{\mathrm{cm}}^{ - 3}$$6–2.2 × 1 × $${10}^{22}{\mathrm{cm}}^{-3}$$ [ 16,28,35,36,37,38,44,46,56–59,63–66,68,69,71 ] have been used in this studies.…”