scholarly journals Spin Polarization Properties of Two Dimensional GaP3 Induced by 3d Transition-Metal Doping

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 743
Author(s):  
Huihui Wei ◽  
Jiatian Guo ◽  
Xiaobo Yuan ◽  
Junfeng Ren
Keyword(s):  
Transition Metal ◽  
Spin Polarization ◽  
Density Functional ◽  
Polarization Property ◽  
First Principles Calculation ◽  
Transition Metal Doping ◽  
Functional Theory ◽  
Density Distributions ◽  
Calculation Results ◽  
Spin Electronic

The electronic structure and spin polarization properties of monolayer GaP3 induced by transition metal (TM) doping were investigated through a first-principles calculation based on density functional theory. The calculation results show that all the doped systems perform spin polarization properties, and the Fe–doped system shows the greatest spin polarization property with the biggest magnetic moment. Based on the analysis from the projected density of states, it was found that the new spin electronic states originated from the p–d orbital couplings between TM atoms and GaP3 lead to spin polarization. The spin polarization results were verified by calculating the spin density distributions and the charge transfer. It is effective to introduce the spin polarization in monolayer GaP3 by doping TM atoms, and our work provides theoretical calculation supports for the applications of triphosphide in spintronics.

Transition-metal doping induces the transition of electronic and magnetic properties in armchair MoS2 nanoribbons

2017 ◽  
Vol 19 (36) ◽  
pp. 24594-24604 ◽  
Author(s):  
Jing Pan ◽  
Rui Wang ◽  
Xiaoyu Zhou ◽  
Jiansheng Zhong ◽  
Xiaoyong Xu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Electronic Structure ◽  
Transition Metal ◽  
Density Functional ◽  
Transition Metal Doping ◽  
Hydrogen Passivation ◽  
Metal Doping ◽  
Functional Theory ◽  
Electronic And Magnetic Properties

The electronic structure, magnetic properties and stability of transition-metal (TM) doped armchair MoS2 nanoribbons (AMoS2NRs) with full hydrogen passivation have been investigated using density functional theory.

scholarly journals First-Principles Calculation of Transition Metal Hyperfine Coupling Constants with the Strongly Constrained and Appropriately Normed (SCAN) Density Functional and its Hybrid Variants

2019 ◽  
Vol 5 (4) ◽  
pp. 69 ◽  
Author(s):  
Dimitrios A. Pantazis
Keyword(s):  
Transition Metal ◽  
First Principles ◽  
Density Functional ◽  
Hyperfine Coupling ◽  
Coupling Constants ◽  
First Principles Calculation ◽  
Chemical System ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Hyperfine Coupling Constants

Density functional theory (DFT) is used extensively for the first-principles calculation of hyperfine coupling constants in both main-group and transition metal systems. As with many other properties, the performance of DFT for hyperfine coupling constants is of variable quality, particularly for transition metal complexes, because it strongly depends on the nature of the chemical system and the type of approximation to the exchange-correlation functional. Recently, a meta-generalized-gradient approximation (mGGA) functional was proposed that obeys all known exact constraints for such a method, known as the Strongly Constrained and Appropriately Normed (SCAN) functional. In view of its theoretically superior formulation a benchmark set of complexes is used to assess the performance of SCAN for the challenging case of transition metal hyperfine coupling constants. In addition, two global hybrid versions of the functional, SCANh and SCAN0, are described and tested. The values computed with the new functionals are compared with experiment and with those of other DFT approximations. Although the original SCAN and the SCAN-based hybrids may offer improved hyperfine coupling constants for specific systems, no uniform improvement is observed. On the contrary, there are specific cases where the new functionals fail badly due to a flawed description of the underlying electronic structure. Therefore, despite these methodological advances, systematically accurate and system-independent prediction of transition metal hyperfine coupling constants with DFT remains an unmet challenge.

MAGNETIC COUPLING CONSTANTS AND SPIN DENSITY DISTRIBUTIONS FOR CYANO-BRIDGED Gd(III)-Fe(III) AND Gd(III)-Cr(III) COMPOUNDS: BROKEN-SYMMETRY AND DENSITY FUNCTIONAL THEORY CALCULATIONS

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2538-2543 ◽  
Author(s):  
YI QUAN ZHANG ◽  
CHENG LIN LUO ◽  
ZHI YU
Keyword(s):  
Density Functional Theory ◽  
Spin Density ◽  
Spin Polarization ◽  
Density Functional ◽  
Population Analysis ◽  
Magnetic Coupling ◽  
Coupling Constants ◽  
Broken Symmetry ◽  
Functional Theory ◽  
Density Distributions

Magnetic coupling constants J for the complete structures of [ Gd(capro) 2( H 2 O )4 Cr(CN) 6]• H 2 O (capro represents caprolactam) (a) and trans-[ Fe(CN) 4(μ- CN )2 Gd ( H 2 O )4 (bpy) ]•4 H 2 O •1.5 bpy (b) have been calculated using hybrid density functional theory (DFT) B3LYP combined with a modified broken symmetry approach (BS). The calculated J value of -0.24 cm-1 for a is very close to the experimental -0.33 cm-1. They both show the antiferromagnetic interaction between Gd(III) and Cr(III) . For b, although the sign of the calculated J value of 4.24 cm-1 is different from that of the experimental -0.38 cm-1, the two values both show the weak magnetic coupling interaction between Gd(III) and Fe(III) . The spin density distributions are discussed on the basis of Mulliken population analysis. For complexes a and b, both transition metal ( Fe(III) or Cr(III) ) and rare earth Gd(III) display a spin polarization effect on the surrounding atoms, where a counteraction of the opposite polarization effects leads to a low spin density on the bridging ligand C1N1 . For the compounds Gd(III) - Cr(III) (a) and Gd(III) - Fe(III) (b) in the HS states, Cr(III) has stronger spin polarization influence on the bridging atoms than Fe(III) even causing the positive spin population on the bridging atom N1 .

Rational design of MoS2 catalysts: tuning the structure and activity via transition metal doping

2015 ◽  
Vol 5 (1) ◽  
pp. 246-253 ◽  
Author(s):  
Charlie Tsai ◽  
Karen Chan ◽  
Jens K. Nørskov ◽  
Frank Abild-Pedersen
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Hydrogen Evolution ◽  
Density Functional ◽  
Rational Design ◽  
Transition Metal Doping ◽  
Functional Theory ◽  
Mos2 Catalysts ◽  
Metal Doped ◽  
Structure And Activity

Density functional theory is used to elucidate and understand the trends in hydrogen evolution activity of transition-metal doped MoS2 catalysts.

STUDY ON BAND STRUCTURE OF NANOPOROUS SILICON THIN FILM

2018 ◽  
Vol 25 (01) ◽  
pp. 1850045
Author(s):  
XUEKE WU ◽  
YANLIN TANG
Keyword(s):  
Thin Film ◽  
Band Structure ◽  
Density Functional ◽  
First Principles Calculation ◽  
Generalized Gradient ◽  
Silicon Thin Film ◽  
Functional Theory ◽  
Nanoporous Silicon ◽  
Matrix Layer ◽  
Calculation Results

We investigate the energy band structure of nanoporous silicon thin film using first principles calculation based on density functional theory (DFT) with the generalized gradient approximation (GGA). The calculation results show that the band gaps of nanoporous silicon increase with increasing porosity, increase with decreasing the thickness of matrix layer, and almost independent of the thickness of pore layer. Moreover, the band structure of nanoporous silicon can be transformed from indirect to direct gap on thin films of (111) and (110) faces. It will be the guidance and reference for the fabrication of porous silicon optoelectronic devices.

Influence of Mg2+ Substitution for Sn4+ on Electronic Structure and Optical Properties of SnO2

2019 ◽  
Vol 11 (10) ◽  
pp. 1387-1394 ◽  
Author(s):  
Haiying He ◽  
Zibin Wu ◽  
Yu Chen ◽  
Zhihao Yang ◽  
Minghuai Yu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Valence Band ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculation ◽  
Energy Band Gap ◽  
Functional Theory ◽  
Calculation Results ◽  
Localization Behavior

First-principles calculation based on density functional theory (DFT) were employed to theoretically study the influence of partially replacing Sn4+ by Mg2+ on the electronic structure and optical properties of SnO2. The calculation results revealed that the Femi level shifted into the valence band, thereby indicating a p-type conductivity character. The energy band gap for SnO2 was found to be narrowed due to Mg2+ doping. Considering that the energy level for Mg 3s orbitals is comparable to that of O 2p orbitals, the localization behavior in the SnO2 valence band was modified. The imaginary part of dielectric functions' spectrum shifted towards lower energy after doping SnO2 with Mg2+, accompanied by an obvious redshift of the absorption edge. Furthermore, the absorption intensity for the doped systems was larger than that of pure SnO2 matrix in the low-energy region.

Spin polarization properties at the spinterface of thiophene/Fe(100): First principles calculations

2017 ◽  
Vol 31 (11) ◽  
pp. 1750072
Author(s):  
L. L. Cai ◽  
Y. L. Tian ◽  
X. B. Yuan ◽  
G. C. Hu ◽  
J. F. Ren
Keyword(s):  
Spin Polarization ◽  
First Principles ◽  
Density Functional ◽  
The Other ◽  
Spin States ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Density Distributions ◽  
Spin Inversion ◽  
Thiophene Molecule

Based on density functional theory (DFT), the spin polarization properties of a thiophene molecule which is adsorbed at Fe (100) surface are discussed. A variety of horizontal and vertical adsorption configurations as well as their influences on the spin density distributions are studied in detail. The spin polarization comes from the [Formula: see text]-[Formula: see text] orbital coupling between the thiophene molecule and the electrode, which leads to the molecules’ energy level shifting and the density of states (DOS) broadening, so the two spin states near the Fermi level are exchange split. It is also found that the interfacial spin polarization is different under different contact configurations, and the biggest one will be obtained when the S atom is directly placed above the Fe atom at the horizontal direction. On the other hand, interface spin inversion can be obtained by adjusting the adsorption position, which will be helpful to build spin sensors.

First-Principles Calculation of Al-Cu-Mg Alloy Strengthening Phase

2015 ◽  
Vol 1096 ◽  
pp. 109-113
Author(s):  
He Ma ◽  
Li Jia Chen ◽  
Lian Quan Guo ◽  
Li Leng ◽  
Lin Lin
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Heat Of Formation ◽  
First Principles Calculation ◽  
Mg Alloy ◽  
First Principles Calculations ◽  
Strengthening Phase ◽  
Functional Theory ◽  
Calculation Results ◽  
Mg Content

In this study, equilibrium lattice parameters, heat of formation and cohesive energy of four kinds of typical phases with different structure intermetallic compound in Al-Cu-Mg alloy were investigated by first-principles calculations based on density functional theory via CASTEP software. The calculation results are analyzed and show that ternary strengthening phase Al2CuMg generated first when Mg content is higher, while binary strengthening phase Al2Cu or Al3Cu2 first generated and more stable when Mg content is low in Al-Cu-Mg alloy which indicates that element Cu and Al alloying capacity significantly higher than that of Mg and Al element.

Elastic and phonon instabilities in simple-cubic heavier alkali metals K, Rb and Cs under hydrostatic pressure studied using ab initio calculations

2014 ◽  
Vol 28 (19) ◽  
pp. 1450158
Author(s):  
Hui Zhao ◽  
Xiao-Sheng Song
Keyword(s):  
Spin Polarization ◽  
First Principles ◽  
Low Temperatures ◽  
Density Functional ◽  
Alkali Metals ◽  
Elastic Stability ◽  
Ambient Condition ◽  
First Principles Calculation ◽  
Functional Theory ◽  
Simple Cubic

Using first-principles calculation based on density functional theory, the elastic stability and dynamic stability of heavier alkali metals K , Rb and Cs in sc structure are investigated. Results reveal that the C44 instabilities are responsible for the mechanical instabilities for these heavier alkali metals and the spin-polarization phases are more stable than non-spin-polarization phases. Other than K - sc which presents BZ edge instability at the M-point at ambient condition, the K - sc and Rb - sc are dynamically stable for the range of the pressure in our calculation. But for Cs - sc , it becomes unstable starting from 7 GPa. Especially we demonstrate that the most stable phases of K at low temperatures and pressures around 20 GPa are ferromagnetic K in sc structure.

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