The geometrical structure of ferromagnetic FeO is optimized. Its electric and magnetic properties such as the half-metallicity, the conductivity and the magnetic moment distribution are investigated by performing first-principles calculations within the generalized gradient approximation for the exchange-correlation function based on density functional theory. Results show that ferromagnetic FeO has 100% spin-polarization at the Fermi level. Its supercell magnetic moments are 32.00 μB, which arise mainly from 3d-orbits of Fe-ions. The electronic structures of Fe-ions are Fe2+t2g3↑eg2↑t*2g1↓.
Half-metallic ferromagnets (HMFs), whose spin-polarization is theoretically ±100% at the Fermi level, are very important spintronic materials. These materials have huge application potential in spintronic devices such as magnetoresistance random access memory (MRAM), read-write magnetic head, spin transistors and magnetic sensors [
For probing the magnetic sequence, the FeO supercell with the NaCl structure containing four Fe-ions and four O-ions was selected and shown in
For studying magnetic and electric properties of ferromagnetic FeO, the bigger supercell containing eight Fe-ions and eight O-ions was optimized and shown in
The spin-polarized total state densities (TDOS) of ferromagnetic FeO is shown in
Partial and local state densities of ferromagnetic FeO are also calculated and shown in
evidently higher than the Fermi level. This shows that there are hybrid orbits from Fe 3d and O 2p orbits. Fe 4s electrons enter into these hybrid orbits and the electronic structure of Fe is Fe2+ 3d6.
Some calculated magnetic and electric parameters of ferromagnetic FeO are shown in
Species | Ion | s | p | d | Total | Charge (e) | Spin (μB) |
---|---|---|---|---|---|---|---|
O | 1 | 1.86 | 4.89 | 0.00 | 6.75 | −0.75 | 0.36 |
Fe | 1 | 0.34 | 0.55 | 6.36 | 7.25 | 0.75 | 3.64 |
O-ligands around one Fe-ion, and then they form the coordinate compound ML6. There is strong octahedral crystal field in ML6, which results in that 3d-orbits of Fe-ions are splitted into bonding orbits containing two eg and three t 2g -orbits with lower energy, and their corresponding anti-bonding orbits containing two
From our calculation, ferromagnetic FeO is a kind of half-metallic ferromagnet. Its primitive magnetic moments are 4.00 μB, which arise from spin polarization of Fe 3d-orbits. The electronic structures of Fe-ions are Fe2+t2g3↑eg2↑t*2g1↓.
JunLiu,WeiKang,XiaolanYang, (2015) First-Principles Calculations on the Half-Metallicity of Rock-Salt Ferromagnetic FeO. Journal of Materials Science and Chemical Engineering,03,1-7. doi: 10.4236/msce.2015.39001