ChemInform Abstract: Spin-Polarization in Half-Metals.

This chapter explains how the exchange splitting between up- and down-spin bands in ferromagnets unexceptionally generates spin-polarized electronic states at the Fermi energy. The quantity of spin polarization P in ferromagnets is one of the important parameters for application in spintronics, since a ferromagnet having a higher P is able to generate larger various spin-dependent effects such as the magnetoresistance effect, spin transfer torque, spin accumulation, and so on. However, the spin polarizations of general 3d transition metals or alloys generally limit the size of spin-dependent effects. Thus,“‘half-metals” attract much interest as an ideal source of spin current and spin-dependent scattering because they possess perfectly spin-polarized conduction electrons due to the energy band gap in either the up- or down-spin channel at the Fermi level.

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Strain-tunable magnetic anisotropy in two-dimensional Dirac half-metals: nickel trihalides

RSC Advances ◽

10.1039/c9ra06474e ◽

2019 ◽

Vol 9 (61) ◽

pp. 35614-35623 ◽

Cited By ~ 4

Author(s):

Zheng Li ◽

Baozeng Zhou ◽

Chongbiao Luan

Keyword(s):

Magnetic Anisotropy ◽

Spin Polarization ◽

High Speed ◽

Ferromagnetic State ◽

Two Dimensional ◽

Half Metals ◽

Conduction Electrons

Combining complete spin-polarization, high-speed conduction electrons, high TC, robust ferromagnetic state and strain-tunable magnetic anisotropy in the monolayer NiX3.

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Magnetic two-dimensional C3N2 carbonitrides: semiconductors, metals and half-metals

Physical Chemistry Chemical Physics ◽

10.1039/c7cp04934j ◽

2017 ◽

Vol 19 (39) ◽

pp. 26743-26748 ◽

Cited By ~ 5

Author(s):

Dimitrios Mpoutas ◽

Leonidas Tsetseris

Keyword(s):

Density Functional Theory ◽

Dft Calculations ◽

Spin Polarization ◽

Density Functional ◽

Two Dimensional ◽

Functional Theory ◽

Half Metals ◽

2D Polymers

Using density-functional theory (DFT) calculations we probe the spin polarization of functionalized two-dimensional (2D) phthalo-carbonitrides (pc-C3N2), i.e., 2D polymers of tetra-cyanoethylene.

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R 3 c-type LnNiO3 (Ln = La, Ce, Nd, Pm, Gd, Tb, Dy, Ho, Er, Lu) half-metals with multiple Dirac cones: a potential class of advanced spintronic materials

IUCrJ ◽

10.1107/s2052252519012570 ◽

2019 ◽

Vol 6 (6) ◽

pp. 990-995 ◽

Cited By ~ 8

Author(s):

Xiaotian Wang ◽

Guangqian Ding ◽

Zhenxiang Cheng ◽

Hongkuan Yuan ◽

Xiao-Lin Wang ◽

...

Keyword(s):

Physical Properties ◽

Fermi Level ◽

Spin Polarization ◽

Three Dimensional ◽

Electromagnetic Response ◽

Dirac Fermions ◽

Strongly Correlated ◽

Half Metals ◽

High Profile ◽

Transport Carrier

In the past three years, Dirac half-metals (DHMs) have attracted considerable attention and become a high-profile topic in spintronics becuase of their excellent physical properties such as 100% spin polarization and massless Dirac fermions. Two-dimensional DHMs proposed recently have not yet been experimentally synthesized and thus remain theoretical. As a result, their characteristics cannot be experimentally confirmed. In addition, many theoretically predicted Dirac materials have only a single cone, resulting in a nonlinear electromagnetic response with insufficient intensity and inadequate transport carrier efficiency near the Fermi level. Therefore, after several attempts, we have focused on a novel class of DHMs with multiple Dirac crossings to address the above limitations. In particular, we direct our attention to three-dimensional bulk materials. In this study, the discovery via first principles of an experimentally synthesized DHM LaNiO3 with many Dirac cones and complete spin polarization near the Fermi level is reported. It is also shown that the crystal structures of these materials are strongly correlated with their physical properties. The results indicate that many rhombohedral materials with the general formula LnNiO3 (Ln = La, Ce, Nd, Pm, Gd, Tb, Dy, Ho, Er, Lu) in the space group R 3 c are potential DHMs with multiple Dirac cones.

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High spin polarization in formamidinium transition metal iodides: first principles prediction of novel half-metals and spin gapless semiconductors

Physical Chemistry Chemical Physics ◽

10.1039/c9cp00958b ◽

2019 ◽

Vol 21 (29) ◽

pp. 16213-16222 ◽

Cited By ~ 5

Author(s):

Hai-Ming Huang ◽

Ming-Lei Cao ◽

Zhen-Yi Jiang ◽

Yong-Chen Xiong ◽

Xiong Zhang ◽

...

Keyword(s):

Electronic Structure ◽

Transition Metal ◽

Spin Polarization ◽

First Principles ◽

Inorganic Hybrid ◽

Half Metals ◽

Hybrid Perovskite ◽

High Spin Polarization ◽

Perovskite Type ◽

Spin Gapless Semiconductors

The electronic structure shows that FAVI3 is a novel organic–inorganic hybrid perovskite-type spin gapless semiconductor.

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Effects of strain on the half-metallicity and spin gapless feature of Ti2YSi (Y = Fe, Co) alloys

Modern Physics Letters B ◽

10.1142/s0217984918501531 ◽

2018 ◽

Vol 32 (14) ◽

pp. 1850153

Author(s):

Xiaoguang Fan ◽

Jincheng Li ◽

Yingjiu Jin

Keyword(s):

Spin Polarization ◽

First Principles ◽

Lattice Parameters ◽

The Other ◽

First Principles Calculations ◽

Half Metallicity ◽

Lattice Constants ◽

Half Metals ◽

Co Alloys ◽

Spin Gapless Semiconductors

Half-metals and spin gapless semiconductors (SGSs), which exhibit 100% spin polarization at the Fermi level, are considered important candidates for spintronics. Using first-principles calculations, we have investigated the effects of uniform strain and tetragonal distortion on the half-metallicity and spin gapless feature of inverse Heusler Ti2YSi (Y = Fe and Co) alloys. Results show that for uniform strains, the half-metallicity occurs in the ranges of lattice parameters from 5.938 Å to 6.535 Å for Ti2FeSi and from 5.924 Å to 6.840 Å for Ti2CoSi. Tetragonal distortions over the ranges of −2.0% to +2.5% and −2.6% to +4.1% could destroy the half-metallicity for Ti2FeSi and Ti2CoSi, respectively. On the other hand, Ti2CoSi is an SGS at lattice constants of 5.968–6.023 Å. An interesting finding is that Ti2CoSi reproduces the SGS character with increasing the lattice parameters to 6.784–6.840 Å. Small tetragonal distortions with ±0.2% will destroy the SGS character of Ti2CoSi.

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