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Half metal in two-dimensional hexagonal organometallic framework.

Hu H, Wang Z, Liu F - Nanoscale Res Lett (2014)

Bottom Line: Two-dimensional (2D) hexagonal organometallic framework (HOMF) made of triphenyl-metal molecules bridged by metal atoms has been recently shown to exhibit exotic electronic properties, such as half-metallic and topological insulating states.The HOMFs show both ferromagnetic and antiferromagnetic properties, as well as nonmagnetic properties, due to the electronic configuration of the TM atoms.The V, Mn, and Fe lattices are ferromagnetic half metals with a large band gap of more than 1.5 eV in the insulating spin channel, making them potential 2D materials for spintronics application.

View Article: PubMed Central - PubMed

Affiliation: Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710054, China, hhu0914@mail.xjtu.edu.cn.

ABSTRACT
Two-dimensional (2D) hexagonal organometallic framework (HOMF) made of triphenyl-metal molecules bridged by metal atoms has been recently shown to exhibit exotic electronic properties, such as half-metallic and topological insulating states. Here, using first-principles calculations, we investigate systematically the structural, electronic, and magnetic properties of such HOMFs containing 3d transition metal (TM) series (Sc to Cu). Two types of structures are found for these HOMFs: a buckled structure for those made of TMs with less half-filled 3d band and a twisted structure otherwise. The HOMFs show both ferromagnetic and antiferromagnetic properties, as well as nonmagnetic properties, due to the electronic configuration of the TM atoms. The V, Mn, and Fe lattices are ferromagnetic half metals with a large band gap of more than 1.5 eV in the insulating spin channel, making them potential 2D materials for spintronics application.

No MeSH data available.


Related in: MedlinePlus

Spin-polarized band structures of the triphenyl-TM lattices. (a-i) Spin-polarized band structures of the triphenyl-TM lattices from Sc to Cu. Black curves in (a) and (g) mean nonmagnetic bands; blue and red curves in other plots are the spin-up and spin-down bands, respectively. Only spin-down (red) bands are shown in (d) and (i) for AFM lattices.
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Fig3: Spin-polarized band structures of the triphenyl-TM lattices. (a-i) Spin-polarized band structures of the triphenyl-TM lattices from Sc to Cu. Black curves in (a) and (g) mean nonmagnetic bands; blue and red curves in other plots are the spin-up and spin-down bands, respectively. Only spin-down (red) bands are shown in (d) and (i) for AFM lattices.

Mentions: For Co, Ni, and Cu, the hybridization between TM and C orbitals becomes too strong. Consequently, we cannot interpret the magnetic behavior based on the above simple argument. Specifically, for the Co lattice, our calculation indicates that the strong hybridization makes the Co 3d orbit become fully filled without magnetism and the Ni magnetic moment be a non-integer number along with non-integer moments on C atoms. The differences in the involvement of 4 s orbitals in bonding are probably the reason why the Sc-to-Cr lattices with s-orbital bonding show buckled structure and the others without s-orbital bonding show twisted structures.To further reveal the electronic properties of these HOMFs, we show their spin-polarized band structures in Figure 3. For Sc and Co, they are nonmagnetic, with degenerate spin-up and spin-down bands. They are insulators with a DFT band gap more than 1.5 eV. For V, Mn, and Fe, the spin-up (blue) and spin-down (red) bands split away from each other, resulting in ferromagnetic half metals. The Ti, Cr, and Cu lattices are antiferromagnetic, with degenerate spin-up and spin-down bands and opposite spins on the two TM atoms in the unit cell. The Ni lattice is a magnetic semiconductor.Figure 3


Half metal in two-dimensional hexagonal organometallic framework.

Hu H, Wang Z, Liu F - Nanoscale Res Lett (2014)

Spin-polarized band structures of the triphenyl-TM lattices. (a-i) Spin-polarized band structures of the triphenyl-TM lattices from Sc to Cu. Black curves in (a) and (g) mean nonmagnetic bands; blue and red curves in other plots are the spin-up and spin-down bands, respectively. Only spin-down (red) bands are shown in (d) and (i) for AFM lattices.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493848&req=5

Fig3: Spin-polarized band structures of the triphenyl-TM lattices. (a-i) Spin-polarized band structures of the triphenyl-TM lattices from Sc to Cu. Black curves in (a) and (g) mean nonmagnetic bands; blue and red curves in other plots are the spin-up and spin-down bands, respectively. Only spin-down (red) bands are shown in (d) and (i) for AFM lattices.
Mentions: For Co, Ni, and Cu, the hybridization between TM and C orbitals becomes too strong. Consequently, we cannot interpret the magnetic behavior based on the above simple argument. Specifically, for the Co lattice, our calculation indicates that the strong hybridization makes the Co 3d orbit become fully filled without magnetism and the Ni magnetic moment be a non-integer number along with non-integer moments on C atoms. The differences in the involvement of 4 s orbitals in bonding are probably the reason why the Sc-to-Cr lattices with s-orbital bonding show buckled structure and the others without s-orbital bonding show twisted structures.To further reveal the electronic properties of these HOMFs, we show their spin-polarized band structures in Figure 3. For Sc and Co, they are nonmagnetic, with degenerate spin-up and spin-down bands. They are insulators with a DFT band gap more than 1.5 eV. For V, Mn, and Fe, the spin-up (blue) and spin-down (red) bands split away from each other, resulting in ferromagnetic half metals. The Ti, Cr, and Cu lattices are antiferromagnetic, with degenerate spin-up and spin-down bands and opposite spins on the two TM atoms in the unit cell. The Ni lattice is a magnetic semiconductor.Figure 3

Bottom Line: Two-dimensional (2D) hexagonal organometallic framework (HOMF) made of triphenyl-metal molecules bridged by metal atoms has been recently shown to exhibit exotic electronic properties, such as half-metallic and topological insulating states.The HOMFs show both ferromagnetic and antiferromagnetic properties, as well as nonmagnetic properties, due to the electronic configuration of the TM atoms.The V, Mn, and Fe lattices are ferromagnetic half metals with a large band gap of more than 1.5 eV in the insulating spin channel, making them potential 2D materials for spintronics application.

View Article: PubMed Central - PubMed

Affiliation: Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710054, China, hhu0914@mail.xjtu.edu.cn.

ABSTRACT
Two-dimensional (2D) hexagonal organometallic framework (HOMF) made of triphenyl-metal molecules bridged by metal atoms has been recently shown to exhibit exotic electronic properties, such as half-metallic and topological insulating states. Here, using first-principles calculations, we investigate systematically the structural, electronic, and magnetic properties of such HOMFs containing 3d transition metal (TM) series (Sc to Cu). Two types of structures are found for these HOMFs: a buckled structure for those made of TMs with less half-filled 3d band and a twisted structure otherwise. The HOMFs show both ferromagnetic and antiferromagnetic properties, as well as nonmagnetic properties, due to the electronic configuration of the TM atoms. The V, Mn, and Fe lattices are ferromagnetic half metals with a large band gap of more than 1.5 eV in the insulating spin channel, making them potential 2D materials for spintronics application.

No MeSH data available.


Related in: MedlinePlus