scholarly journals High-Pressure-Induced Transition from Ferromagnetic Semiconductor to Spin Gapless Semiconductor in Quaternary Heusler Alloy VFeScZ (Z = Sb, As, P)

2019 ◽  
Vol 9 (14) ◽  
pp. 2859 ◽  
Author(s):  
Haishen Huang ◽  
Kun Yang ◽  
Wan Zhao ◽  
Tingyan Zhou ◽  
Xiude Yang ◽  
...  
Keyword(s):  
Heusler Alloy ◽  
Density Functional ◽  
External Pressure ◽  
Ferromagnetic Semiconductors ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Metallic Ferromagnetism ◽  
Half Metallic Ferromagnetism ◽  
Pressure Phase

In this paper, the structure and the electronic and magnetic properties of VFeScZ (Z = Sb, As, P) series alloys are systematically studied based on the Perdew–Burke–Ernzerhof (PBE) generalized gradient approximation (GGA) calculation within the first-principles density functional theory. The results showed that VFeScSb and VFeScP are ferromagnetic semiconductors and VFeScAs exhibits half-metallic ferromagnetism under zero pressure. As the pressure increases, the narrow indirect gap of VFeScZ (Z = Sb, As, P) alloy gradually decreases, and gets close to zero, leading to spin gapless semiconductor (SGS) transition. The pressure phase transition point of VFeScSb, VFeScAs, and VFeScP alloy is 132 GPa, 58 GPa, and 32 GPa, respectively. As a result, the pressure effect provides an opportunity to tune the electronic properties of the alloys by external pressure. The present findings provide a technical method for us to actually use the Heusler alloy SGS.

An Investigation of Half-Metallic Ferromagnets Behavior in Hg2CuTi-Type Heusler Alloy Ti2FeAl by Using GGA

2012 ◽  
Vol 535-537 ◽  
pp. 1291-1294 ◽  
Author(s):  
Xiu De Yang ◽  
Bo Wu ◽  
Song Zhang
Keyword(s):  
Density Functional Theory ◽  
Heusler Alloy ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Generalized Gradient Approximation ◽  
Indirect Exchange ◽  
The Density Functional Theory ◽  
Direct Hybridization

By using generalized gradient approximation (GGA) scheme within the density functional theory (DFT), the electronic and magnetic properties of Hg2CuTi-type Heusler alloy Ti2FeAl were investigated. The results reveal that a 100% spin polarization appears at Fermi level (εF) in Ti2FeAl, and is maintained during lattice range of 5.1Å~6.2Å. Ti2FeAl is one of stable Half-Metallic Ferromagnets (HMF) with a spin-minority gap of 0.5 eV at εF and total magnetic moment of 1μB per unit cell. Our studies also indicate that the competition between RKKY-type indirect exchange and direct hybridization of d-electronic atoms plays a dominating role in determining the magnetism.

scholarly journals Structural, elastic, electronic, and magnetic properties of quaternary alloys BBi0.75Mn0.125N0.125 : a first-principles study

2020 ◽  
Vol 66 (5 Sept-Oct) ◽  
pp. 627
Author(s):  
S. Tab ◽  
A. Boudali ◽  
M. Berber ◽  
M. Driss khodja ◽  
O. Lhaj El Hachemi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Ferromagnetic Phase ◽  
Generalized Gradient ◽  
Quaternary Alloys ◽  
Functional Theory ◽  
Half Metallic ◽  
Electronic And Magnetic Properties ◽  
First Time ◽  
Metallic Ferromagnetism

In this study, we have employed the first-principle methods based on density functional theory to investigate the structural, elastic, electronic and magnetic properties of BBi0.75Mn0.125N0.125. The exchange and correlation potential are described by the generalized gradient approximation of Perdew, Burke and Ernzerhof (GGA-PBEsol) + SOC coupled with TB-mBJ approaches. The studied structure show that the compound BBi0.75Mn0.125N0.125 is stable in ferromagnetic phase, the elastic property indicate that the structure is brittle and mechanically stable. The half metallic description is predicted with energy spin band gap in spin up channel. The structure attributed half-metallic ferromagnetism could be suitable for spintronics devices. To our knowledge, this is the first time that a study has been done on this alloy and we would like it to serve as a reference for the next studies.

Half-metallic ferromagnetism in hypothetical wurtzite structure chromium chalcogenides

2004 ◽  
Vol 19 (9) ◽  
pp. 2738-2741 ◽  
Author(s):  
Ming Zhang ◽  
Ekkes Brück ◽  
Frank R. de Boer ◽  
Guodong Liu ◽  
Haining Hu ◽  
...  
Keyword(s):  
Density Functional ◽  
Wurtzite Structure ◽  
First Principle ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Metallic Ferromagnetism ◽  
Half Metallic Ferromagnetism

The hypothetical wurtzite structure chromium chalcogenides were investigated through first-principle calculation within density-functional theory. All compounds are predicted to be true half-metallic ferromagnets with an integer Bohr magneton of 4 μB per unit. Their half-metallic gaps are 1.147, 0.885, and 0.247 eV at their equilibrium volumes for wurtzite-type CrM (M = S, Se, and Te), respectively. The half-metallicity can be maintained even when volumes are expanded by more than 20% for all compounds and compressed by more than 20%, 20%, and 5%, for CrS, CrSe, and CrTe, respectively.

Half-metallic ferromagnetism in Wurtzite MS (M = Li, Na, and K)

2012 ◽  
Vol 90 (6) ◽  
pp. 531-536 ◽  
Author(s):  
M. Moradi ◽  
M. Rostami ◽  
M. Afshari
Keyword(s):  
Density Functional ◽  
Wurtzite Structure ◽  
First Principle ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
First Principle Calculations ◽  
Consistent Method ◽  
Metallic Ferromagnetism ◽  
Half Metallic Ferromagnetism

The magnetic properties of MS (M = Li, Na, K) compounds in a Wurtzite structure at zero pressure are investigated by using first principle calculations and the pseudopotential self-consistent method based on density functional theory. It is shown that MS compounds in Wurtzite structure are half-metallic ferromagnets with a magnetic moment of μB per formula unit and half-metallic gaps of 0.24, 0.52, and 0.62 eV for LiS, NaS, and KS, respectively. We also consider the effect of pressure on the half-metallicity of these compounds and we find that LiS, NaS, and KS in Wurtzite structure maintain their half-metallicity up to lattice compressions of 9%, 37%, and 60%, respectively, and as a result one can grow them over the semiconductors in Wurtzite structures that are produced experimentally. These properties cause Wurtzite MS compounds to be appropriate choices to create useful devices in spintronics.

scholarly journals Half-metallic ferromagnetism and band gap reduction in Cu-doped zinc-blende BeO: first-principle study -=SUP=-*-=/SUP=-

2017 ◽  
Vol 59 (5) ◽  
pp. 835
Author(s):  
L. Kahal
Keyword(s):  
Band Gap ◽  
Density Functional ◽  
Ferromagnetic State ◽  
Partial Density ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Half Metallic ◽  
Zinc Blende ◽  
Metallic Ferromagnetism ◽  
Half Metallic Ferromagnetism

In this paper, we report ferromagnetism in copper doped zinc-blende BeO. Our first-principles calculations based on spin density functional theory predicts a total magnetic moment of 1 muB per copper when copper substitutes beryllium in BeO, where 0.58 muB is localized at Cu atom. The results obtained show that the ferromagnetic state is 34 meV lower than the antiferromagnetic state. Calculations indicate an appreciable band gap reduction in BeO. The analysis of the partial density of states reveals that ferromagnetism and reduction of BeO band gap are principally due to the strong p-d coupling of O and Cu. DOI: 10.21883/FTT.2017.05.44367.337

Density functional theory investigation of half-metallic ferromagnetism in V-doped GaP alloys

2020 ◽  
Vol 497 ◽  
pp. 166067 ◽  
Author(s):  
Mohammed El Amine Monir ◽  
Aïcha Bahnes ◽  
Abdelkader Boukortt ◽  
Abdelkarim Bendoukha Reguig ◽  
Younes Mouchaal
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Half Metallic ◽  
Metallic Ferromagnetism ◽  
Half Metallic Ferromagnetism
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