scholarly journals Half-Metallicity and Magnetism of the Quaternary Heusler Compound TiZrCoIn1−xGex from the First-Principles Calculations

2019 ◽  
Vol 9 (4) ◽  
pp. 620 ◽  
Author(s):  
Ying Chen ◽  
Shaobo Chen ◽  
Bin Wang ◽  
Bo Wu ◽  
Haishen Huang ◽  
...  
Keyword(s):  
Fermi Level ◽  
First Principles ◽  
Magnetic Moments ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Valence Electrons ◽  
The Stability ◽  
Formation Energies ◽  
Quaternary Heusler Compound ◽  
Ge Doping

The effects of doping on the electronic and magnetic properties of the quaternary Heusler alloy TiZrCoIn were investigated by first-principles calculations. Results showed that the appearance of half-metallicity and negative formation energies are associated in all of the TiZrCoIn1−xGex compounds, indicating that Ge doping at Z-site increases the stability without damaging the half-metallicity of the compounds. Formation energy gradually decreased with doping concentration, and the width of the spin-down gap increased with a change in Fermi level. TiZrCoIn0.25Ge0.75 was found to be the most stable half-metal. Its Fermi level was in the middle of the broadened gap, and a peak at the Fermi level was detected in the spin majority channel of the compound. The large gaps of the compounds were primarily dominated by the intense d-d hybridization between Ti, Zr, and Co. The substitution of In by Ge increased the number of sp valence electrons in the system and thereby enhanced RKKY exchange interaction and increased splitting. Moreover, the total spin magnetic moments of the doped compounds followed the Slater–Pauling rule of Mt = Zt − 18 and increased from 2 μB to 3 μB linearly with concentration.

Magnetism and Half-Metallicity in (100) Surface of Inverse Heusler Mn2CoSb

2014 ◽  
Vol 1015 ◽  
pp. 377-380
Author(s):  
Tao Chen ◽  
Ying Chen ◽  
Yin Zhou ◽  
Hong Chen
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
First Principles ◽  
Heusler Alloy ◽  
Density Functional ◽  
Magnetic Moments ◽  
Surface States ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Functional Theory

Using the first-principles calculations within density functional theory (DFT), we investigated the electronic and magnetic properties of (100) surface of inverse Heusler alloy Mn2CoSb with five different terminations. Our work reveals that the surface Mn atom moves to vacuum while surface Co atom moves to slab. Moreover, duo to the reason that the surface atom lost half of the nearest atoms with respect to the bulk phase, resulting in the decrease of hybridization, the atom-resolved spin magnetic moments of surface atoms are enhanced. Further investigation on DOS and PDOS showed that half-metallicity was preserved only in SbSb-termination while was destroyed in MnCo-, MnSb-, MnMn-, and CoCo-termination due to the appearance of surface states.

STABLE STRUCTURES, ELECTRIC AND MAGNETIC PROPERTIES OF NANOPARTICLES COn(n = 1-6) CLUSTERS: FIRST-PRINCIPLES CALCULATIONS

2013 ◽  
Vol 27 (15) ◽  
pp. 1362007
Author(s):  
JUN LIU ◽  
SHENG-BIAO TAN ◽  
HUI-NING DONG
Keyword(s):  
Magnetic Properties ◽  
Ground State ◽  
First Principles ◽  
Lower Energy ◽  
Magnetic Moments ◽  
Molecular Orbitals ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Ground State Structures ◽  
Stable Structures

The ground state geometric structures of the nanoparticles or clusters CO n(n = 1-6) were given based on the first-principles calculations. Then the magnetic properties of the clusters CO n(n = 1-6) and ( CO n)-2(n = 1-6) were calculated in system. Results show that their ground state structures are closely related to the numbers of O-ions. These clusters have no magnetic moments and half-metallicity if they are electroneutral. However, they have magnetic moments if they have positive or negative charges. The total magnetic moments of the clusters ( CO n)-2(n = 1-6, but n≠3) are all 2.0000 μB, and all their ions have contributions to the total magnetic moments. The main reason is that the molecular orbitals with lower energy filled with paired electrons and the molecular orbitals with higher energy are occupied by two electrons in parallel.

Pressure-Induced Tunable Magnetism and Half-Metallic Stability in Co2FeGa Heusler Alloy

2013 ◽  
Vol 477-478 ◽  
pp. 1303-1306
Author(s):  
Qin Xiang Gao
Keyword(s):  
Fermi Level ◽  
First Principles ◽  
Density Functional ◽  
High Energy ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Heusler Compound ◽  
The Density Functional Theory

Using the first-principles calculations within the density functional theory (DFT), we have investigated the structure, magnetism and half-metallic stability of Co2FeGa Heusler compound under pressure from 0 to 50GPa. The results revel that the lattice constant is gradually shrank and total magnetic moment in per unit slightly decreased with increasing pressure, respectively. Moreover, with the increase of the pressure, the Fermi level will move towards high-energy orientation. When the pressure reaches at 30GPa the most stable half-metallicity is observed which the Fermi level is located at the middle of the spin-minority gap.

Magnetic properties of C–N planar structures: d0 ferromagnetism and half-metallicity

2015 ◽  
Vol 17 (47) ◽  
pp. 31995-31999 ◽  
Author(s):  
W. H. Brito ◽  
Joice da Silva-Araújo ◽  
H. Chacham
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Carbon Nitride ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Planar Structures ◽  
Formation Energies ◽  
D0 Ferromagnetism ◽  
Planar Carbon

We investigate, from first principles calculations, the magnetic properties of planar carbon nitride structures with the lowest formation energies within twenty eight distinct stoichiometries and porosities.

Electronic and magnetic properties of F atoms adsorbed on TiO2:Mn(001) diluted magnetic semiconductor surfaces: First-principles calculations

2014 ◽  
Vol 28 (18) ◽  
pp. 1450096 ◽  
Author(s):  
Chunlei Wang ◽  
Dan Li ◽  
Yuan Niu ◽  
Hongmin Zhao ◽  
Chunjun Liang
Keyword(s):  
First Principles ◽  
Formation Energy ◽  
Diluted Magnetic Semiconductor ◽  
Magnetic Moments ◽  
Magnetic Semiconductor ◽  
First Principles Calculations ◽  
Ion Doping ◽  
Diluted Magnetic ◽  
The Stability ◽  
Mn Doped

We performed first-principles calculations for two Mn -doped structures in which Mn atoms substitute Ti atoms to determine whether (i) it is more conducive to Mn ion doping and (ii) ferromagnetism can occur in F adsorption anatase TiO 2 surfaces. Ferromagnetic (FM) coupling is more stable than antiferromagnetic (AFM) coupling for all doping configurations as the adsorption of F atoms on the surface significantly lowers the formation energy of the TiO 2: Mn system. The magnetic moments of the Mn ions are reduced, whereas those of O atoms on the surface are increased. The magnetic moment of the O atoms is mainly derived from the spin polarization p x and p y orbitals. F adsorption promotes doping of Mn atoms and to a certain extent improves the stability of the structure, magnetism and metallicity.

Effect of Nb Doping on Electronic and Magnetic Properties of Heusler Alloy Ti2NiAl with Hg2CuTi-Type Structure

2012 ◽  
Vol 535-537 ◽  
pp. 1295-1298 ◽  
Author(s):  
Ying Chen ◽  
Bo Wu ◽  
Hong Chen
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Function Theory ◽  
Type Structure ◽  
First Principles Calculations ◽  
Ni Doping ◽  
Half Metallicity ◽  
Electronic And Magnetic Properties ◽  
Valence Electrons ◽  
Nb Doping

In this work, the electronic and magnetic properties of Nb-doped full-Huesler alloy Ti2NiAl with Hg2CuTi-type structure have been investigated by using first-principles calculations within the density function theory (DFT). Due to the Nb which has less valence electrons than Ni doping into Ni-site, the gap around the Fermi level of the compound Ti2Ni1-xNbxAl (0≤x≤1) is gradually narrowed, and destroyed completely as x≥0.5. With the increase of x, it has gone through the transition from the ferromagnetism to the non-magnetism, and then to the ferromagnetism finally. Further analyses of density of states reveal that the d-electronic rehybridization induced by Nb-doping and RKKY-type indirect interaction is directly responsible for the changes of half-metallicity and magnetism.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

scholarly journals Anion ordering and vacancy defects in niobium perovskite oxynitrides

2021 ◽  
Vol 2 (7) ◽  
pp. 2398-2407
Author(s):  
Joshua J. Brown ◽  
Youxiang Shao ◽  
Zhuofeng Ke ◽  
Alister J. Page
Keyword(s):  
First Principles ◽  
First Principles Calculations ◽  
Defect Engineering ◽  
Vacancy Defects ◽  
The Stability

First-principles calculations predict the stability and mobility of vacancy defects in niobium perovskite oxynitrides, aiding defect engineering for enhanced photocatalysis.

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