Total DOS Research Articles

Effect of transition metals (Fe, Ru and Os) on the elastic, thermodynamic, electronic, magnetic and thermoelectric properties of three Nd-filled arsenide skutterudites based on first-principles computations

Elastic, electronic, magnetic, thermodynamic, and thermoelectric properties of three neodymium-filled skutterudites NdT4As12 (T = Fe, Ru and Os) have been investigated using density functional theory. The bulk moduli increase with the atomic numbers of the transition metals. All materials are stiff, while the Os compound is the stiffest. A considerable ionic contribution is seen in their inter-atomic bonding. The Fe compound possesses the highest Debye temperature, while the Os compound has the highest melting temperature. GGA+U formalism predicts the semimetallic nature of all the compounds, but their total DOS differs near the Fermi level in both spin channels. The contributions of the Nd-f and T-d electrons differ in the three compounds and two methods. GGA+U predicts the highest magnetic moment in the Fe compound, followed by the Ru and Os compounds. The thermoelectric figure of merit shows no systematic variation with z of the transition metals and in the high temperature region it increases with temperature pretty fast. The highest value of ZT is 0.32 in the Ru compound in the spin-down channel while it is 0.24 in the spin-up channel in the Fe compound, both at 1000 K.

The Effect of Silicon Substitution by Boron for the α-Nb5Si3: INSIGHTS into the Constitutive Properties of Nb5Si2B Through Theory and Experimental Approach

We investigated the structural, elastic, vibrational, and electronic properties of the Nb5Si2B compound combining density functional theory (DFT) calculations and experimental methods. We compared our results with the parent compound Nb5Si3 with two non-equivalent Si sites namely Si(4a) and Si(8h). The analysis of elastic constants and phonon spectra indicate that Nb5Si2B is respectively mechanically and dynamically stable. Based on the phonon calculation we evaluate the theoretical constant volume lattice specific heat (CV) for different site occupancies and compare it with experimental specific heat (Cp) measurements. We found an excellent agreement between theoretical and experimental results for Nb5Si2B with the B at the Si(8h) site, which agrees with the calculated formation energy. In addition, we also performed DFT calculations aimed at showing and comparing the total DOS near the Fermi level (EF) for Nb5Si3 and Nb5Si2B. The XPS valence band (VB) of the Nb5Si2B is largely dominated by two characteristic peaks at − 8.7 and − 1.7 eV, respectively. Based on DFT calculations, it follows that the main sharp peak at − 1.7 eV comes as a contribution from Nb 4d states, while the smaller and broader one located at − 8.7 eV results mainly from Si 3s states weakly hybridized with Nb 4d states. In this connection, the majority contribution in the binding energy range from − 12 eV to the EF comes from Nb 4d states, while the contribution from Si and B atoms is very small in this region. The core levels of Nb 3d, Si 2s, 2p, and B 1s were also identified using the XPS technique.

Effect of F− doping on structural, elastic, and electronic properties of SmO1−xFxBiS2: A first principles investigation

Structural, elastic, and electronic properties of SmO1−xFxBiS2 were studied using first principles method, and effects of F− doping were clearly observed. By increasing x, the increase of lattice parameter ‘a’ and decrease of ‘c’ are mainly due to the displacement of S1 and Sm atoms respectively. For x = 0.3, new (Bi–S1)2 bonds formation was observed. The gap between Bi- and S1-planes decreases and disappeared at x = 0.9. Cauchy pressures, B/G, and ν indicate ductile nature having metallic bonds with small ionic contribution. B, G, and E are highly anisotropic and show anomaly at x = 0.3, 0.5, and 0.8. Sm 4f states are mainly responsible for metallicity. For x = 0.3, total DOS decreases due to new bonds formation. Anomalous displacement of Sm-sites by doping at O- or Sm-sites induces anomalous displacement of S1 atoms which may be the main reason for change of different properties of SmO1-xFxBiS2.

Weak electronic correlations observed in magnetic Weyl Semimetal Mn3Ge

Using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations, we systematically studied the electronic band structure of Mn3Ge in the vicinity of the Fermi level. We observe several bands crossing the Fermi level, confirming the metallic nature of the studied system. We further observe several flat bands along various high symmetry directions, consistent with the DFT calculations. The calculated partial density of states suggests a dominant Mn 3d orbital contribution to the total valence band DOS. With the help of orbital-resolved band structure calculations, we qualitatively identify the orbital information of the experimentally obtained band dispersions. Out-of-plane electronic band dispersions are explored by measuring the ARPES data at various photon energies. Importantly, our study suggests relatively weaker electronic correlations in Mn3Ge compared to Mn3Sn.

Lead-free Perovskites TlGeClxBr3-x (x=0,1,2,3) as Promising Materials for Solar Cell Application: a DFT Study

This study investigates the structural parameters and the electronic properties of cubic TlGeClxBr3-x (x=0,1,2,3) lead-free perovskites to evaluate their potential as absorbers in perovskite solar cell devices. Density Functional Theory (DFT) embedded in the Quantum Espresso code was used to calculate these properties. The results revealed that the compounds have optimized lattice constants of 5.244 Å, 5.336 Å, 5.416 Å, and 5.501 Å, for TlGeCl3, TlGeCl2Br, TlGeClBr2, and TlGeBr3 perovskites, respectively. In addition, the compounds are direct band gap (R→R) semiconductors with energy gap values of 0.847 eV, 0.683 eV, 0.556 eV, and 0.518 eV for the respective materials. It is important to note that the band gap of the perovskites reduces as a Cl− ion, two and three Cl− ions are replaced by a Br− ion, two and three Br− ions, respectively. The analysis of their projected density of states indicated that near the valence band maximum of the perovskites, Cl-3p and Br-4p states contributes the most to their total DOS. In contrast, the Ge-4p orbital is the most dominant state close to the conduction band minimum. Based on these energy gap values, the studied materials are promising candidates for lead-free perovskite solar cell devices, with TlGeBr3 projected to be more promising than the other three materials.

High-throughput calculation for superconductivity of sodalite-like clathrate ternary hydrides MXH12 at high pressure

Inspired by the experimental synthesis of the first theoretically predicted clathrate hydride CaH6 with high Tc of 215 K at 172 GPa, we designed a series of Pm-3m phase ternary hydrides MXH12 and performed high-throughput calculations. Ten compounds were discovered, among which YHfH12, YThH12, ScZrH12, and LaThH12 show good superconductivity with critical temperatures above 150 K. LaThH12 and YCeH12 can be dynamically stable at a minimum of 100 GPa. Aiming at a comprehensive description of the H24 cage that dominates the superconductivities of MXH12, we proposed a variable AE, which is defined as the average ELF value at the center of all the H–H bonds in the cage-like hydrides. Combining the AE with the contribution of the H element to the total DOS at the Fermi level, we constructed a simple liner model (called the AE model) by fitting the data of hydrides MXH12. The mean absolute error is 11.7 K suggesting a strong linear correlation between AE and Tc. Furthermore, the AE model can be generalized to predict the superconductivity of other cage-like hydrides such as LaH10 (or YH10) with H32 cage, YH9 (or CeH9) with H29 cage, and more complex cage-like hydrides such as La4H23 and LaBeH8. The AE model could estimate the Tc of clathrate hydrides with small computational cost and provide reliable reference for further high-throughput calculations and experimental research.

Ab-initio investigation of structural, opto-electronic, and thermodynamic properties of ZnAl2Se4 for photovoltaic applications

In this manuscript, the structural, opto-electronic, and thermodynamic properties of ZnAl2Se4 chalcogenide compounds were studied in detail using the full potential linearized augmented plane wave method. The exchange and correlation potentials used in density functional theory were calculated using local density approximation, the generalized gradient approximation (GGA) method, and the modified Becke–Johnson (mBJ) potential using Wien2k code. The obtained results were compared with each other as well as with available experimental data. At ambient conditions, ZnAl2Se4 is a direct wide bandgap (Г–Г) semiconductor with a bandgap of 2.1 and 3.3 eV with GGA and mBJ potentials, respectively. Density of states (DOS; total DOS and Partial Density Of States (PDOS)) and electron density contour plots were in similar accordance with bandgap, showing semiconductive behavior and covalent bonding nature. The optical properties like the real and imaginary parts of the dielectric constant, the energy loss function L( ω), and the conductivity σ( ω) were calculated. Optical aspects show interaction among phonon and electron in terms of long-range and short-range forces. The studied compound is very useful for various linear–nonlinear optical devices, so this compound is very valuable for several linear–nonlinear optical devices. So this manuscript represents a comprehensive approach for calculating the complete set of useful properties of the ZnAl2Se4 compound, which can provide support for understanding various device phenomena such as electrochemical sensing, photovoltaics, and nonvolatile electronic memories.

Ab initio prediction of optoelectronic and thermoelectric behavior of Eu‐doped Zn2SnO4 using GGA + U functional: A study for optoelectronic devices

AbstractTo understand the electronic structure and optical properties of Zn2SnO4 and Eu‐doped compounds, we utilized the full potential linearized augmented plane wave method with the generalized gradient approximation (GGA). To analyze the electronic, optical, and thermoelectric properties of Eu‐doped Zn2SnO4, we implemented the GGA‐PBE + U method within density functional theory. We obtained the density of states (total and partial DOS) and optical constants (absorption coefficient, refractive index, reflectivity, and optical conductivity). Our findings revealed that the near‐Fermi valence bands (VB) of the band structure are primarily due to the O and Eu atoms. The electronic properties, including the band structure and TDOS/PDOS, particularly the hybridization among Eu s and f along with Zn s and d states, demonstrated that the pristine material's VB and conduction bands are located at the G point, indicating a direct band gap. However, the Eu‐doped material exhibits intermetallic behavior. We used the electronic structures to analyze the dielectric (real and imaginary parts) function and related properties, such as absorption coefficient, reflectivity, energy loss function, and refractive index. Consequently, in the low‐energy zone, the refractive index and the dielectric constant increased. With the presence of impurity bands, the width of the band gap decreased significantly, and the absorption spectrum shifted toward the red region, indicating a robust response in the infrared band, with high utilization efficiency. Moreover, the Zn2SnO4‐doped samples showed the best improvement in optical properties in the low‐energy region.

Noble metal single-atom catalyst supported by C[formula omitted]N[formula omitted] monolayer as a promising reduction electrocatalyst for low-density environmental NO

Here, we show that the noble metal atoms decorated over the porous monolayer of C8N8 demonstrate superior performance in the reduction reaction of low-density environmental NO gas. Among different considered single-atom catalysts (SAC), the osmium atom exhibits the most energetically favored NO-reduction pathway with the free energy change of −12.71 eV even at low NO coverage. Both nitrogen- and carbon-dominated large rings are capable of adsorbing NM atoms to form NM@C8N8 configurations. Fortunately, no clustering resulted for the noble metal atoms anchored onto the pristine C8N8 due to the substantial binding energy of −12.87 eV. The considered SACs exhibit their electrocatalytic activities by the dominant contribution to the total DOS around the Fermi level, especially for the Os, Ir, and Rh adatoms. At low NO coverage, NOER over Os@C8N8 proceeds the downhill profile diagram and demonstrates promising electrocatalytic performance in NO-reduction. Similarly, at high NO coverage, N2O2 can be adsorbed by NM@C8N8, due to the negative value of the free energy change.

First-principles investigation of the structural, electronic and optical properties of Zn2NbN3

An ab initio study using density functional theory (DFT) is carried out to explore the structural, electronic, and opticalproperties of Zn2NbN3 compound. The structural properties of these compound are determined by using the approximation(GGA-PBE) as implemented in WIEN2k. The calculated lattice parameters of the Zn2NbN3 compound are found to bea = 9.91 °A, b = 5.81 °A and c = 5.44 °A . The calculated electronic band structure and density of states indicate that theZn2NbN3 compound is a wide gap semiconductor with a direct band gap of 2.5 eV. The different contributions of the electronicorbitals are discussed using the total and partial DOS with PBE and TB-mBJ approximations , which shows significantcontribution from the Nb-d and N-p. The optical properties such as dielectric function, refractive index, absorption coefficient,and extinction coefficient are calculated and discussed.

A Comparative XPS, UV PES, NEXAFS, and DFT Study of the Electronic Structure of the Salen Ligand in the H2(Salen) Molecule and the [Ni(Salen)] Complex.

A comparative study of the electronic structure of the salen ligand in the H2(Salen) molecule and the [Ni(Salen)] complex was performed using the experimental methods of XPS, UV PES, and NEXAFS spectroscopy along with DFT calculations. Significant chemical shifts of +1.0 eV (carbon), +1.9 eV (nitrogen), and -0.4 eV (oxygen) were observed in the 1s PE spectra of the salen ligand atoms when passing from a molecule to a complex, unambiguously indicating a substantial redistribution of the valence electron density between these atoms. It is proposed that the electron density transfer to the O atoms in [Ni(Salen)] occurred not only from the Ni atom, but also from the N and C atoms. This process seemed to be realized through the delocalized conjugated π-system of the phenol C 2p electronic states of the ligand molecule. The DFT calculations (total and partial DOS) for the valence band H2(Salen) and [Ni(Salen)] described well the spectral shape of the UV PE spectra of both compounds and confirmed their experimental identification. An analysis of the N and O 1s NEXAFS spectra clearly indicated that the atomic structure of the ethylenediamine and phenol fragments was retained upon passing from the free salen ligand to the nickel complex.

Selective Photochemical Oxidation of Reduced Dissolved Organic Sulfur to Inorganic Sulfate.

The chemical nature and stability of reduced dissolved organic sulfur (DOSRed) have implications on the biogeochemical cycling of trace and major elements across fresh and marine aquatic environments, but the underlying processes governing DOSRed stability remain obscure. Here, dissolved organic matter (DOM) was isolated from a sulfidic wetland, and laboratory experiments quantified dark and photochemical oxidation of DOSRed using atomic-level measurement of sulfur X-ray absorption near-edge structure (XANES) spectroscopy. DOSRed was completely resistant to oxidation by molecular oxygen in the dark and underwent rapid and quantitative oxidation to inorganic sulfate (SO42-) in the presence of sunlight. The rate of DOSRed oxidation to SO42- greatly exceeded that of DOM photomineralization, resulting in a 50% loss of total DOS and 78% loss of DOSRed over 192 h of irradiance. Sulfonates (DOSSO3) and other minor oxidized DOS functionalities were not susceptible to photochemical oxidation. The observed susceptibility of DOSRed to photodesulfurization, which has implications on carbon, sulfur, and mercury cycling, should be comprehensively evaluated across diverse aquatic environments of differing DOM composition.

First principle calculations of the structural, elastic, electronic and transport properties of XRuAs (X = Ta and V)

The structural, electronic, elastic, and transport properties of Ruthenium Arsenide based Tantalum and Vanadium (XRuAs (X = Ta and V)) half heusler alloys were investigated as a promising thermoelectric material. In determining the properties of these compounds, density functional theory (DFT), as implemented in Quantum Espresso and Boltztrap codes were used. The alpha atomic position gave the lowest minimum energy and was used for all other calculations. The lattice constants, electronic band structure, total and partial density of state and the elastic properties of the compounds were determined. The electronic band structure calculation showed that TaRuAs and VRuAs were semiconductors with an indirect bandgap of 0.17 eV and 0.42 eV, respectively. The d-orbital of the Ruthenium atom in both compound were responsible for the huge peak observed in the total DOS. The elastic properties showed that the alloys are mechanically stable, ductile and elastically anisotropic. The transport properties calculated are the Seebeck coefficient, power factor, and electronic thermal conductivity. The maximum Seebeck coefficient at 1000 K is 286.30 μV/K and 212.06 μV/K, while the maximum electrical conductivity obtained at 1000 K is 4.99 S/ms and 4.11 S/ms. The power factor obtained at 1000 K for VRuAs and TaRuAs were 185.37 W/msK2 and 166.25 W/msK2. At 1000 K, an electronic thermal conductivity (TC) of 8.59 W/mK was obtained for TaRuAs, and 8.01 W/mK was obtained for VRuAs. Figures of merit of 0.58 and 0.77 are obtained for VRuAs and TaRuAs, respectively, at 1000 K which is a limit and the final value may be lower with the computation of the lattice thermal conductivity. The Electronic Fitness Functions (EFF) was determined to further screen the compounds. Values of 1.4 W5/3 ms1/3 K2 and 0.77 W5/3 ms1/3 K2 are obtained, which are comparable with the values obtained for high-performance thermoelectric materials. The results showed that while both compounds are good thermoelectric materials, TaRuAs is the better of the two compounds with a higher figure of merit. Moreover, the results obtained from the EFF calculation suggests that the TaRuAs is a good thermoelectric material. As far as we know, the results obtained for TaRuAs have not been presented in any literature.

Molecular Structure, Spectroscopic Assessment, PDOS, Topology Evaluation and Docking Studies of 2-Chloro-5-nitrobenzophenone

The vibrational, electronic properties of 2-chloro-5-nitrobenzophenone (2C5NB) are explored experimentally, and theoretically (DFT) using B3LYP functional with LanL2DZ basis set. This has been performed for assignment vibrational frequencies that conjointly involves inserting beneficial evidence concerning the structure of the chosen compound. Based on PED, a comprehensive clarification of the FT-Infrared and FT-Raman spectra of the designated molecule were documented, with these studies agreeing satisfactorily with the experimental data. By mapping the total electron density isosurface with MEP, and contour map, charge density distribution and chemical reactivity spot of the 2C5NB were studied. Molecule stability ascending from hyper conjugative interactions and charge delocalization were explored using NBO analysis. For energies, the HOMO-LUMO diagram has been depicted. The transitions of the compound expression is (n→π*) in the UV-Vis region. The chemical changes of the molecule in 1H and 13C nuclear magnetic resonance were measured using the Gauge-Independent Atomic Orbital (GIAO) method and analysed using 1H and 13C NMR spectra. The non-zero value of μ and elevated β worth specify that the 2C5NB might be a good candidate for NLO content. In order to explore the simultaneous correlations of the different bonds of the 2C5NB, the total and partial DOS spectrum were intricated. Fukui functions were made to treasure the reactive site all over the molecule. The thermodynamic properties have been accomplished. The docking of molecule studies disclosed that the 2C5NB molecule performances a central role in binding proteins that inhibit L-glutamate oxidase. Minimum binding energy and intermolecular energy is perceived in the interaction.

Structural phase transitions and magnetism of Cr doped InN under high pressure

The density functional theory (DFT) calculations within the generalized gradient approximation + U (GGA + U) had been performed to acquire the electronic structure, enthalpy, and magnetic properties of Cr0.5In0.5N under hydrostatic pressure of 0 GPa–20 GPa, the three common structures of InN were used as doped subjects to study related properties of Cr doped InN, including wurtzite (B4), zinc-blende (B3) and rocksalt phase (B1). The enthalpy calculations demonstrated the doped system would occur structural phase transitions at high pressure, and the transition pressures were 7.20 GPa and 9.09 GPa for B4 to B1 and B3 to B1, respectively. Moreover, the total DOS and partial DOS showed a half-metallic character for all doped structures, also showed spin polarization of Cr0.5In0.5N. The total magnetic moment and local magnetic moment were investigated from the ferromagnetic structures of Cr0.5In0.5N, the total magnetic moment of B1 was always 3 μB under normal pressure or high pressure, however, the total magnetic moment of B3 increased with pressure, and it would reach a maximum of 3 μB under high pressure. What's more, we found that the Curie temperature (TC) of B3 decreased slowly with pressure increasing, and the TC was higher than room temperature under the pressure of less than 20 GPa all the time.

The Doping Effect on the Electronic Properties of the Titanium Dioxide TiO2: A DFT Study

In this work, we study the electronic and magnetic properties of the TiO2 material doped by the some elements, such as Sulfur (S), Fluorine (F), Hydrogen (H), Nitrogen (N), Potassium (K), Boron (B), Iodine (I) and Carbon (C). We have used the ab-initio method on the basis of the Density Functional Theory (DFT) using the Quantum Espresso code. Our calculations show three behaviors: semiconductor, half metallicity and full metallic. In fact, a first step, our results confirm the semi-conductor character of the pure TiO2 with a direct band gap of about 1.7 eV at the Γ point. In the partial density of states, the O-2p orbital is found to be dominant in the valence band of the total DOS. While, the Ti-3d orbital is overriding in the conduction band of the total DOS of TiO2 material. When doping the TiO2 with Fluorine (F), we found that the band structure of the doped TiO2 material exhibits an indirect gap between M and Γ points. On the second step, the main character of TiO2 doped with F, H and N is a half metallic behavior. Finally, when doping with the (K), (B), (I) or (C) elements, we found a full metallic behavior of this material. It is worth to note that the doping TiO2 material with Boron (B) and Iodine (I) makes appear a low magnetic character, while a more important magnetic behavior appear when doping the TiO2 with Carbon. It is found that the fact of doping TiO2 is to make it less stable.

Cubic to tetragonal structural phase transformation in NaNbO3 with peculiar Mg and Ca doping and its repercussions on optoelectronic properties

By using computation, scrutinize the impact of doping on phase stability, phase transformation, electronic band structure, and optical properties of NaNbO3 are reported. At peculiar doping concentrations (4.22% Mg, 7.04% Mg, 4.22% Ca and 7.04% Ca), cubic to pseudo-cubic tetragonal phase transformation occurs. The total DOS, partial DOS and elemental PDOS explain the effect of phase transformation on band structure. In all cases of doping, the value of band gap increases and the nature of band gap for 4.22% doping concentrations remains same as that of pure and becomes direct band gap for 1.40% and 7.04% doping concentrations. From optical properties, we observed a red shift in the absorption spectra and the refractive index increases from 2.60 to 3.80 and 3.90 with Ca- and Mg-doping, respectively.

In silico exploration of O-H…X2+ (X = Cu, Ag, Hg) interaction, targeted adsorption zone, charge density iso-surface, O-H proton analysis and topographic parameters theory for calix[6]arene and calix[8]arene as model

In this work, the best adsorption targeted zones of the metal cations Ag2+, Cu2+ and Hg2+ at the surfaces or inside, outside the cavity of the calix[6] (CX[6]), calix[8]arene (CX[8]), NUBMOM (NUB-.) and LAYKUR (LAY-.) have been discussed. For X2+=Ag, Cu and Hg adsorbed onto the surface of CX[6,8], NUB-., and LAY-. and the morphologies of these complexes have been explained, the specific chosen surface structure has interfacial chemical properties to facilitate the stabilization of the cation in each targeted zone. The stability mechanisms have been investigated for the specific systems to understand the role of the cooperativity of the O…H (forming a donor-acceptor couple) bonding interactions for good selectivity to the cation in each host-guest in the acetonitrile solvent medium and the gas phase. For this purpose, all the host-guests chemical structures were investigated by the IR spectroscopy and O-H proton approach. The UV–visible absorption spectroscopy and the total DOS Orbital showed that all molecules possess a maximum absorption band in the range between 0.5 and 3.5 eV assigned to π–π* or n-π* transitions, the minimum band is characterized for the CX[6,8]-Cu2+, NUB-.Cu2+ and LAY-.Cu2+, while the highest band is specified for the complexation with the cation Ag2+. The Hirshfeld surface and the molecular electrostatic potential topography have demonstrated the selected targeted zone for the most stable configurations. The nature and the type of interaction formed between the chosen cation and the targeted area of the CX[6,8], NUB-. and LAY-. were typically studied by the Atom in Molecules (AIM) approach via non-covalent interaction (NCI) analyses. According to theoretical calculations, Cu2+, Ag2+ and Hg2+ cations were complexed with CX[6] and CX[8]-arenes in endo and exo-type form. In the endo complexes, it has been observed that Cu2+and Ag2+ cations enter the lower rim space where calixarene hydroxyl groups are located and form a complex in square planer geometry, as expected. This situation shows that the copper cation is planarly located in the calixarene core. These results show that the theoretical results are in good agreement with the experimental ones. In addition, our simulations point out the calix[6] arene and calix[8]arene were complexed with cations by “pinched” conformation, corresponding to best stable state.

Half-Metallic and Magnetic Properties for Cu2O Nanowire: Ab-initio Study

The investigation of structural stability, electronic and magnetic properties of Cu2O nanowire, in the direction of growth (100) and (111) having square: Cu2O-S(m,n) and hexagonal: Cu2O-H(m,n) cross-section respectively and diameter ranging from ∼(7-15)Å, has been done by using standard Density Functional Theory based on ab-initio self-consistent approach with generalized gradient approximation employing spin polarized case parameterized by revised Perdew Burke Ernzerhoff functional. Here, the binding energy calculation shows that as the cross-section of both the nanowires increases, the binding energy also increases which indicates that the nanowire having smallest cross-section is the least stable and vice-versa. Interestingly, from the analysis of electronic properties it can be concluded that the considered Cu2O nanowire exhibit half metallic nature showing the 100% of spin polarization at Fermi energy Ef. The asymmetric nature of spin up and spin down density of states shown by total DOS plot suggests us that all the Cu2O nanowire structures are magnetic in nature. Here, we found that there is decrease in total calculated magnetic moment per atom with increase in cross-sectional diameter but the total magnetic moment per unit cell gives the integer value with increased status. Also, the analysis of spin orientation of Cu and O atoms shows that both atoms are Ferro magnetically spin polarized with each other indicating the Cu2O nanowire is half-metallic ferromagnetic semiconductor.

First-principles study of the structural, electronic, and magnetic properties of Mn-doped Ni3XN(X=Al, Cu, In) compounds

Density functional theory is used to investigate the structural, elastic, electronic and magnetic properties of the anti-perovskite Ni3XN (X: Al, Cu, In). The calculated lattice parameters are found consistent with the experimental or empirical values. The analysis shows that Ni3AlN, Ni3InN, and Ni3CuN are obviously ductile materials, and they possess metallic-like bonding. The electronic band structures show metallic conductivity. It is seen that Ni-3d, Mn-3d and N-2p states dominate the total DOS at the Fermi level. Mn-doping not only changes the Fermi energy, but also changes the magnetic properties of the Ni3XN compounds. The calculated results show that Ni2·5Mn0·5AlN Ni2·5Mn0·5CuN and Ni2·5Mn0·5InN are ferrimagnetic, their unit cell magnetic moments are 2.38μB, 7.48μB, and 5.40μB, respectively.