Total Magnetic Moment Research Articles

Searching for new two-dimensional spintronic materials: Doping-induced magnetism in graphene-like SrS monolayer

In this work, doping approach is explored to induce feature-rich electronic and magnetic properties in graphene-like SrS monolayer and make it prospective spintronic two-dimensional (2D) candidate. For such goal, 3d transition metals (V, Cr, Mn, and Fe) and halogens (F, Cl, Br, and I) are selected as dopants at Sr and S sublattice, respectively. Pristine SrS single layer shows good dynamical and thermal stability. Its indirect-gap semiconductor nature is also asserted with energy gap of 2.87/3.81 eV obtained by PBE/HSE06 functional, generated by the separation in energy between S-3p and Sr-4d orbitals. The magnetic semiconducting with total magnetic moment of 2.00 μB is obtained by creating a single Sr vacancy, meanwhile S single vacancy preserves the non-magnetic nature. The monolayer is significantly magnetized by doping with transition metals, where large total magnetic moments of 3.00, 4.00, and 5.00 μB are obtained for the V-, Cr/Fe-, and Mn-doped SrS monolayer, respectively. In these cases, impurities play a key role on producing magnetic properties and generating the magnetic semiconductor nature. This feature-rich nature is also induced by doping with F atom, where a total magnetic moment of 1.00 μB is obtained that is originated mainly from Sr atoms closest to the doping site. Besides, Cl doping leads to the emergence of the half-metallicity. Importantly, the magnetization becomes significantly weaker according to increase the atomic number of halogen dopants, such that the non-magnetic nature is preserved by doping with I atom. This feature is attributed to the increase of the electronic hybridization. Results presented herein introduce the doped SrS monolayer as promising 2D spintronic materials, exhibiting novel properties that are not found in the pristine counterpart.

Inducing d 0 magnetism in new SrCl2 monolayer towards spintronic applications

Magnetism engineering in two-dimensional (2D) materials has been widely explored to make new spintronic materials. In this work, the doping (with alkali metals at Sr sublattice and with chalcogen atoms at Cl sublattice) method are proposed to induce significant d 0 magnetism in the non-magnetic SrCl2 monolayer. This 2D material is an indirect gap insulator with large band gap of 4.97(6.25) eV as obtained by PBE(HSE06) functional, exhibiting ionic character that is generated by the charge transfer from Sr atom to Cl atoms. The monolayer is significantly magnetized by doping with alkali metals, where a total magnetic moments between 0.90 and 1.00 μ B are obtained. Herein, Cl atoms closest to the doping site make main contribution to the system magnetism. Interestingly, the doped systems exhibit half-metallic behavior that is generated by semiconductor spin-up state and metallic spin-down state. On the other hand, the diluted magnetic semiconductor nature emerges in SrCl2 monolayer as a result of doping with chalcogen atoms. In these cases, total magnetic moment of 1.00 μ B is obtained, where magnetic properties are produced mainly by chalcogen impurities and Cl atoms below them. The electronic and magnetic properties of the doped systems are regulated mainly by the outermost p orbital of Cl and chalcogen atoms, and Sr-4d orbital that form mainly the conduction band. Upon further increasing the doping level of K and O atoms, the half-metallic or magnetic semiconductor natures are preserved. Results presented in this work may introduce new prospective 2D spintronic candidates for spintronic applications, which are derived from a non-magnetic SrCl2 monolayer via doping with d 0 atoms.

Exploring of Be1-xCrxSe alloys for spintronics and optoelectronic applications

In this study, spin polarized density functional theory (DFT) is implemented to predict physical characteristic of Be1-xCrxSe (x = 6.25%, 12.5%, 18.75%, 25%) compound. The electronic characteristics of pure BeSe compound show semiconductor behavior but after Cr doping BeSe elucidate half-metallic ferromagnetism (HMF) for all doping concentrations. The outcomes elucidate the total magnetic moment MTot per Cr-atom are 4.0028, 4.0027, 4.0021 and 4.0002 μB for 6.25%, 12.5%, 18.75%, 25% concentrations, respectively and the magnetism mainly originated from d-state of the impurity atom which is further ensured from the magnetic spin density. Furthermore, the optical parameters are also computed to determine the effect of doping on the material’s response to incident light of energy spanning from 0 to 10 eV. The optical study depict that the studied systems possess maximum absorbance and optical conductivity in UV-range with minimal reflection. The overall outcomes illustrate that the Cr doped beryllium selenide (BeSe) is promising material for spintronic and optoelectronic devices.

Elastic, electronic, magnetic and magnetocaloric properties of janus MnXO (X=S, Se and Te) monolayers: First-principles and Monte Carlo investigations

In this work, we present the first theoretical analysis of the elastic, electronic, magnetic and magnetocaloric properties of 1T-phase Janus MnXO (X = S, Se and Te) monolayers using first-principle calculations based on density functional theory combined with Monte Carlo simulation. The stability of the studied monolayers has been analyzed by using the elastic constants Cij and formation energy, which indicate that all monolayers are stable. Moreover, the electronic properties reveal the metal characteristics of all monolayers, with a total magnetic moment of 3.25 μB, 3.81 μB and 4.09 μB for MnSO, MnSeO, and MnTeO, respectively. Further, the extracted critical temperature values (Tc) from Monte Carlo simulation are Tc = 115 K, Tc = 130 K and Tc = 82 K, for MnSO, MnSeO and MnTeO, respectively. Interestingly, the predicted maximum magnetic entropy change −ΔSmax and maximum relative cooling power RCP (and adiabatic temperature change) are 10,38 J/kg.K and 763,43 J/kg (7,11 K) for MnSO, 6,79 J/kg.K and 515,57 J/kg (3,25K) for MnSeO, and 6,39 J/kg.K and 407,16 J/kg (3,46 K) for MnTeO at a magnetic field of 5T. These results suggest that the Janus MnXO (X = S, Se and Te) monolayers are a potential materials for use in magnetic nanodevices and low-dimensional magnetic refrigeration.

Investigation of structural, magnetic, mechanical, electronic and thermal properties of new quaternary Heusler: KMgNZ (Z=O or S)

The structural stability as well as the mechanical, magnetoelectronic and thermal properties of the quaternary Heusler KMgNZ (Z = O or S) were studied using first principles approach based on the DFT implemented in Wien2k code. The exchange-correlation potential is treated by PBE-GGA. The calculated negative formation energies for both materials corroborate their thermodynamic stability. Moreover, the derived elastic constants support the mechanical stabilities of the latter compounds. On the other hand, the density of states of the studied materials shows that both compounds are half-metallic ferromagnets. The total magnetic moments for both compounds are mainly originated from N atom, and its integer value followed the Slater-Pauling rule. The calculated half-metallic gaps are found for two systems. The three-dimensional plots of different mechanical moduli exhibit that the bulk modulus is isotropic, whereas Young's modulus, Poisson's ratio and shear modulus of both compounds are highly anisotropic. The effects of temperature and pressure on the heat capacity, thermal expansion coefficient and Debye temperature are also studied.

Point Defects in Hexagonal SiP Monolayer: A Systematic Investigation on the Electronic and Magnetic Properties

AbstractIn this work, point defects are proposed to modify the electronic and magnetic properties of SiP monolayer. Pristine monolayer is a non‐magnetic semiconductor 2D material with energy gap of 1.52(2.21) eV as predicted by PBE(HSE06) functional. Single Si vacancy (), Si+P divacancy (), and substituting one P atom by one Si atom () magnetize significantly SiP monolayer. Herein, total magnetic moments between 1.00 and 2.00 are obtained . In contrast, no magnetism is induced by single P vacancy (), substituting one Si atom by one P atom (), and exchanging pair Si‐P positions (). Moreover, significant magnetization of SiP monolayer is also achieved by doping with single Li and Cu atoms ( and ), as well as pair of Li and Cu atoms ( and ). Total magnetic moments between 0.84 and 1.42 are obtained. Interestingly, the half‐metallicity is observed in and systems. When substituting P atom, F, Cl, and Br impurities reduce significantly the SiP monolayer bandgap, preserving its non‐magnetic nature. In contrast, a total magnetic moment of 1.26 is obtained by doping with I atom. Results presented herein may introduce the defected and doped SiP systems as prospective 2D candidates for spintronic and optoelectronic applications.

Study of structural, dynamical stability, electronic magnetic and optical properties of RbSnO3 oxide perovskite compound using the density functional theory approach

This study investigates the structural, phonon, elastic, electronic, magnetic and optical properties of cubic perovskite RbSnO3. The calculations are based on the linearized augmented plane wave method with total potential (FP-LAPW), implemented in the Wien2k code; two approximations are used for calculate properties, PBE-GGA and TB-mBJ . The values of the tolerance factor and the formation energy of this material indicate that it is stable in the cubic structure of Pm3̅m symmetry. The Born criteria for the compound under study confirm its mechanical stability, while its phonon dispersion curves confirm its dynamic stability. The results of the electronic and magnetic properties show that the compound is ferromagnetic (FM) semi-metallic (DM) with semiconductor behavior in the majority spin channel and with an indirect gap in the M → Γ direction and having a total magnetic moment equal to 1 μB and a Curie temperature equal to 527 K. Optical spectra of the compound show high optical conductivity in the infrared region and towards the end of the spectrum at around 6 eV, high reflection in the infrared region with a maximum at 0.25 eV, and high absorption in the ultraviolet region at 6 eV. In view of these results, the RbSnO3 perovskite can be a promising candidate for spintronics applications as it can be used in optical devices working in the ultraviolet (UV) light region.

Exploration of new Janus GeBrI monolayer for optoelectronic and spintronic applications

Two-dimensional (2D) materials have been explored for diverse applications, where multifunctional candidates with two or more functions are desired. In this work, new Janus GeBrI monolayer with interesting electronic and magnetic properties is investigated. Standard PBE and hybrid HSE06 functionals assert the indirect gap semiconductor behavior of pristine monolayer with band gap of 2.28 and 3.04 eV, respectively. Novel feature-rich properties can be induced in Janus GeBrI monolayer by defect engineering and doping. Specifically, single Ge vacancy (VGe) metalizes the monolayer without magnetism. Similarly, the non-magnetic nature is kept by doping with IIA-group (Be and Mg: BeGe and MgGe) atoms, where the energy gap exhibits a slight increase of the order between 1.32% and 3.51%. In contrast, this 2D material is significantly magnetized by single halogen vacancy (VBr and VI), doping with IIIA-group (Al and Ga: AlGe and GaGe) atoms, and doping with chalcogen (Se and Te: SeBr, SeI, TeBr, and TeI) atoms. In these cases, total magnetic moments between 0.61 and 1.00 μB are obtained, where impurities and those atoms closest to the defect/doping site originate mainly the system magnetism. Moreover, VBr, VI, AlGe, GaGe systems exhibit the diluted magnetic semiconductor nature, while SeBr, SeI, TeBr, and TeI systems are classified as 2D half-metallic structures. Further, Bader charge analysis indicates the charge loser of IIIA- and IIA-group impurities when transferring charge to the host monolayer. Meanwhile, chalcogen dopants are charge gainers attracting charge from the host monolayer. The presented results introduce new stable Janus GeBrI monolayer with relative large intrinsic band gap, further functionalization processes based on the vacancy defects and doping of this 2D material may make prospective 2D spintronic materials.

Origins of multi-sublattice magnetism and superexchange interactions in double–double perovskite CaMnCrSbO6

The multi-sublattice magnetism and electronic structure in double–double perovskite compound CaMnCrSbO6 is explored using density functional theory. The bulk magnetization and neutron diffraction suggest a ferrimagnetic order ( TC∼ 49 K) between between Mn2+ and Cr3+ spins. Due to the non-equivalent Mn atoms (labelled as Mn(1) and Mn(2) which have tetrahedral and planar oxygen coordinations, respectively) and the Cr atom in the centre of distorted oxygen octahedron in the unit cell, the exchange interactions are more complex than that expected from a two sublattice magnetic system. The separations between the on-site energies of the d-orbitals of Mn(1), Mn(2) and Cr obtained from Wannier function analysis are in agreement with their expected crystal field splitting. While the DOS obtained from non spin-polarized calculations show a metallic character, starting from Hubbard U = 0 eV the spin-polarized electronic structure calculations yield a ferrimagnetic insulating ground state. The band gap increases with Ueff (U − J), thereby showing a Mott–Hubbard nature of the system. The inclusion of anti-site disorder in the calculations show decrease in band-gap and also reduction in the total magnetic moment. Due to the ∼90∘ superexchange, nearest neighbour exchange constants obtained from DFT are an order of magnitude smaller than those reported for various magnetic perovskite and double-perovskite compounds. The Mn(1)–O–Mn(2) (out of plane and in-plane), Mn(1)–O–Cr and Mn(2)–O–Cr superexchange interactions are found to be anti-ferromagnetic, while the Cr–O–O–Cr super-superexchange is found to be ferromagnetic. The Mn(2)–O–Cr superexchange is weaker than the Mn(1)–O–Cr super-exchange, thus effectively resulting in ferrimagnetism. From a simple 3-site Hubbard model, we derived expressions for the antiferromagnetic superexchange strength JAFM and also for the weaker ferromagnetic JFM . The relative strengths of JAFM for the various superexchange interactions are in agreement with those obtained from DFT. The expression for Cr–O–O–Cr super-superexchange strength ( J~SS ), which has been derived considering a 4-site Hubbard model, predicts a ferromagnetic exchange in agreement with DFT. Finally, our mean field calculations reveal that assuming a set of four magnetic sub-lattices for Mn2+ spins and a single magnetic sublattice for Cr3+ spins yields a much improved T C , while a simple two magnetic sublattice model yields a much higher T C .

Adjustment of ferromagnetism and improvement of the electronic structure of the TiI3 monolayer by the substitutional doping of 3d transition metal atoms: Ab-initio investigation

Two dimensional Van der Waals materials are very attractive for several researchers because of their distinctive properties and their interesting applications in data storage and spintronic devices. Titanium triiodide (TiI3), which is classified among transition metal trihalides (MX3), has received more attention after CrI3 and VI3 monolayers. Here, we explore the structural, electronic and magnetic properties of pure and 3d TM (TM = Sc, V, Cr, Mn and Fe) doped TiI3 monolayer using first-principles calculations, based on the GGA + Ueff approach. We confirmed the dynamic stability of TiI3 monolayer using phonon calculations and the thermal stability of pure and TM-doped TiI3 monolayers by performing AIMD simulation. We further found that the pure TiI3 monolayer is a stable ferromagnetic semiconductor with intrinsic magnetism. The introduction of vacancy defects in the pristine TiI3 monolayer showed that it is desirable to introduce TM atoms into Ti positions, which led to the improvement of its electronic and magnetic properties. The Sc-doped system keeps its semiconductor behavior with a reduction in the width of the band gap, whereas V-, Cr- and Fe-doped TiI3 monolayers turn into half semiconductors (HSC). Even more impressive, the Mn-doped system is found to be a bipolar ferromagnetic semiconductor (BFMS). We applied spin orbit coupling (SOC) on simulated monolayers, and showed that it affected them by changing their band gaps widths, especially in Fe-doped TiI3 monolayer. Furthermore, we found in all doped systems a ferromagnetic stability, an enhancement of the total magnetic moment, up to 10 μB in Cr- and Fe-doped monolayers, high Curie temperatures, up to 260 K, and high magnetic anisotropic energies, especially in Mn-doped TiI3 monolayer which makes it possess a long range ferromagnetic order. These interesting results concerning the electronic and magnetic properties of pure and transition metals-doped TiI3 monolayers are extremely beneficial for tune and enhance electronic and spintronic devices.

Modulating electronic and magnetic properties of monolayer Mo8S12 by adatom adsorption: A first-principles study

Monolayer Mo8S12 is a recently discovered two-dimensional (2D) nanomaterial with a moderate band gap and ultra-high carrier mobility, making it highly promising for applications in 2D electronic devices. In this investigation, we utilized spin-polarized first-principles calculations to comprehensively investigate the electronic and magnetic properties of monolayer Mo8S12 by adsorbing metal (Li and Be) and non-metal atoms (H, B, C, N, O, F, and P). Our investigations revealed that these atoms can chemisorb onto monolayer Mo8S12 at various stable positions. The band structures of the O-Mo8S12 system showed nonmagnetic semiconductor behavior, whereas the H-, B-, C-, N-, F-, and P-Mo8S12 systems exhibited the features of magnetic semiconductors. Remarkably, the Li- and Be-Mo8S12 systems displayed half-metallic behavior. Furthermore, the monolayer Mo8S12 adsorbed with H, Li, Be, B, C, N, F, and P atoms resulted in total magnetic moments of 1, 1, 2, 3, 2, 1, 1, and 1 μB, respectively. These findings highlight the potential for manipulating the performance of monolayer Mo8S12 through adsorption. Consequently, our study offers valuable theoretical insights for the design and development of innovative electronic, optoelectronic and spintronic devices based on monolayer Mo8S12.

Synergistic manipulation of physical properties of Ni-Mn-In-B alloys by atomic occupancy and magnetic states

The physical properties of the Ni-Mn-In-B alloys synergistically modulated by atomic occupancy and magnetic states are systematically investigated. The results indicate that B atoms are indirectly substituted at the Mn2 position in the Ni2Mn1.5In0.5 alloy (i.e., B→In→Mn2). When B is doped in interstitial positions, the B atoms tend to be closer to Mn atoms rather than In atoms. Additionally, the higher the concentration of Mn around the B atom, the lower the formation energy of the austenite (A) phase. The lattice parameters of the A phase decreases with increasing x content, while c/a and phase stability gradually decrease for the 4 O, 6 M, and NM martensites in the ferrimagnetic (FIM) state. The magnetostrain of the alloy shows an increasing trend with increasing B content due to the decrease in c/a resulting in a decrease in the tangent variable S= |c/a-a/c|; however, the elastocaloric properties decrease due to the decrease in the volume change ΔV/VA after the transformation. The Ni2Mn1.5-xIn0.5Bx (0≤x≤0.042) alloys undergo an AFM→6 MFIM→NMFIM transformation. The total magnetic moment of the A phase decreases, whereas those of the 4O, 6M, and NM phases increase with increasing x content. The phase stability is explained by analyzing the total densities of states (TDOS) from an electronic structure perspective.

Engineering the half-metallic and magnetic semiconductor natures in gallium phosphide monolayer towards spintronic applications

In this work, magnetism engineering in the Gallium phosphide (GaP) monolayer is explored in order to create new two-dimensional (2D) spintronic materials. Pristine monolayer is a non-magnetic indirect gap semiconductor with band gap of 1.61(2.49) eV obtained from the PBE(HSE06)-based calculations. Both ionic and covalent characters form the Ga-P chemical bond, which are generated by the charge transfer and electronic hybridization, respectively. It is found that creating a single Ga vacancy magnetizes significantly GaP monolayer (VGa), where a large total magnetic moment of 2.88 μB is obtained and magnetic properties are produced mainly by P atoms around the defect site. Meanwhile, GaP monolayer is metallized under effects of single P vacancy, where the non-magnetic nature is preserved. Significant magnetization is also achieved by doping with alkali (Li and Na - LiGa and NaGa) and alkaline earth (Be and Mg - BeGa and MgGa) metals. In these cases, total magnetic moments of 2.00 and 1.00 μB are obtained, respectively. Besides, doping with S (SP) and Se (SeP) atoms induces weaker magnetization, which is reflected in smaller total magnetic moments of 0.60 and 0.96 μB, respectively. Interestingly, the half-metallicity is observed in VGa, BeGa, and MgGa systems; while LiGa, NaGa, and SeP systems exhibit the diluted magnetic semiconductor behavior. In contrast, Cl (ClP) and Br (BrP) impurities induces no magnetism in GaP monolayer. However both ClP and BrP systems have energy gap of 0.76 eV, which corresponds to a reduction of the order of 52.80% from that of pristine monolayer. Results presented herein may introduce efficient methods to modify the GaP monolayer electronic and magnetic properties, such that new multifunctional 2D materials can be created for spintronic and optoelectronic applications.

Exploring stable half-metallicity and magnetism of Cr-based double half-Heusler alloys and its high magnetoresistance ratio in magnetic tunnel junction

A new series of double half-Heusler (DHH) alloy Cr2FeCoZ2 (Z = As, Ge, S, P) are investigated by using the non-equilibrium Green's function in combination with the first-principles calculations. The calculations on magnetism reveal that these Cr-based DHH alloys are ferrimagnets due to the antiparallel magnetic coupling between Cr and Fe (Co). The electronic structure calculations of the Cr-based DHH alloys reveal half-metallicity, and Cr2FeCoAs2 possesses the largest spin-down gap of 1.181 eV. Within the c/a ranges from 1.60 to 2.52, Cr2FeCoAs2 maintains its 100 % spin-polarization, and the changes in total and spin-resovled atomic magnetic moment are negligible, showing a stable half metallicity and magnetism against the tetragonal distortion. Futhermore, the transport properties are investigated by constructing the Cr2FeCoZ2/GaAs/Cr2FeCoZ2 magnetic tunnel junction (MTJ) model. By changing the magnetic arrangement of the left and right electrodes into antiparallel configuration, the capability of transportation in both spin channels is significantly limited. Conversely, by modulating the magnetic arrangement of the left and right electrodes into parallel configuration, the transportation of electrons in spin-up channel is exceptionally strong while that of the spin-down channel is severely impeded. The Cr2FeCoAs2/GaAs/Cr2FeCoAs2 MTJ owns the highest tunneling magnetoresistance (TMR) ratio of ∼7.42 × 108 %, indicating that Cr2FeCoAs2 is the most promising candidate for high performance spintronic devices.

The study of physical properties of ternary intermetallic MnXGe (X=Al and Ga) alloys: Via DFT and Monte Carlo simulation

The present work aims to investigate the physical properties of the ternary intermetallic MnXGe (X = Al and Ga) using density functional theory (DFT) and Monte Carlo simulation. The obtained ground state results reveal that MnXGe (X = Al and Ga) are stable in the ferromagnetic phase with a metallic character. The total magnetic moments of bulk structure (2D layer MnXGe(001)) are 2.13μB(2.325μB) and 2.30μB(3.28μB) for MnAlGe and MnGaGe, respectively, with the total moments coming mainly from the Mn atom. The ferromagnetic behavior is confirmed by the obtained density of state at the Fermi level and verified by the Stoner criterion. The mechanical, thermodynamic and transport properties show that the alloys are stable with brittle behavior and exhibit weak thermoelectric efficiency. The Monte Carlo simulation demonstrates that the critical temperatures (TC) are 540 K for MnAlGe(001) and 460 K for MnGaGe(001) with lattice size L = 30.

A DFT calculation of electronic structures, magnetic, and thermoelectric properties of the new equiatomic quaternary Heusler alloy RuTiCrSi

AbstractThe stabilities, mechanical, electronic, and magnetic properties of the new equiatomic quaternary Heusler alloy (EQHA) RuTiCrSi were investigated using the Kohn‐Sham DFT (KS‐DFT) calculations within the generalized gradient approach (GGA), the modified version of the exchange potential introduced by Becke and Johnson in addition to the GGA (mBJ‐GGA), and Heyd‐Scuseria‐Ernzerhof (HSE06) hybrid functional. The ground‐state equilibrium energy reveals that the ferromagnetic with type 2 structure is the more stable. The RuTiCrSi is energetically, mechanically, and dynamically stable. The calculated self‐consistent total magnetic moment is 2 μB and agrees well with the Slater‐Pauling rule of . The electronic structure results from mBJ‐GGA and HSE06 functionals show a half‐metallic behavior. A high Curie temperature is obtained using the mean‐field approximation. The thermoelectric response was calculated using the semi‐classical Boltzmann transport equation under constant relaxation time. The maximum value of Seebeck coefficient is observed at the ambient temperature of . It was also observed that the power factor increases significantly as temperature rises. Therefore, the new EQHA RuTiCrSi seems to be a potential candidate for spintronic thermoelectric applications.

Effect of Y element on atomic structure, glass forming ability, and magnetic properties of FeBC alloy

Abstract The atomic structure of amorphous alloys plays a crucial role in determining both their glass-forming ability and magnetic properties. In this study, we investigate the influence of adding the Y element on the glass-forming ability and magnetic properties of Fe86−x Y x B7C7 (x = 0, 5, 10 at.%) amorphous alloys via both experiments and ab initio molecular dynamics simulations. Furthermore, we explore the correlation between local atomic structures and properties. Our results demonstrate that an increased Y content in the alloys leads to a higher proportion of icosahedral clusters, which can potentially enhance both glass-forming ability and thermal stability. These findings have been experimentally validated. The analysis of the electron energy density and magnetic moment of the alloy reveals that the addition of Y leads to hybridization between Y-4d and Fe-3d orbitals, resulting in a reduction in ferromagnetic coupling between Fe atoms. This subsequently reduces the magnetic moment of Fe atoms as well as the total magnetic moment of the system, which is consistent with experimental results. The results could help understand the relationship between atomic structure and magnetic property, and providing valuable insights for enhancing the performance of metallic glasses in industrial applications.

Investigation of Structures, Stabilities, and Electronic and Magnetic Properties of Niobium Carbon Clusters Nb7Cn (n = 1-7).

The geometrical structures, relative stabilities, and electronic and magnetic properties of niobium carbon clusters, Nb7Cn (n = 1-7), are investigated in this study. Density functional theory (DFT) calculations, coupled with the Saunders Kick global search, are conducted to explore the structural properties of Nb7Cn (n = 1-7). The results regarding the average binding energy, second-order difference energy, dissociation energy, HOMO-LUMO gap, and chemical hardness highlight the robust stability of Nb7C3. Analysis of the density of states suggests that the molecular orbitals of Nb7Cn primarily consist of orbitals from the transition metal Nb, with minimal involvement of C atoms. Spin density and natural population analysis reveal that the total magnetic moment of Nb7Cn predominantly resides on the Nb atoms. The contribution of Nb atoms to the total magnetic moment stems mainly from the 4d orbital, followed by the 5p, 5s, and 6s orbitals.

DFT study of the half‐metallic variant perovskites A2OsX6 (A = Rb/Cs; X = Cl/Br) for spintronic and thermoelectric applications

AbstractWe present our results of the spin‐polarized calculations on the structural, magneto‐electronic, thermodynamic, and thermoelectric properties of vacancy‐ordered double perovskites A2OsX6 (A = Rb/Cs; X = Cl/Br). We utilized the Wu‐Cohen generalized gradient approximation (Wu‐GGA) and the mBJ scheme to determine a more reliable electronic structure. The compounds exhibit negative formation energy, suitable tolerance factor, and a stable phonon spectrum, indicating their stability. The compounds show half‐metallicity, acting as semiconductors with direct band gaps between 2 and 3 eV in the spin‐up orientation while metallic in the spin‐down. Each compound shows a total spin magnetic moment of 2.00 μB per formula unit, with Os‐t2g states contributing the most (~1.5 μB). The computed thermoelectric coefficient indicates the usability of these compounds across a wide temperature range (200–800 K) with high electrical conductivity and low electronic thermal conductivity. The compounds exhibit high Seebeck coefficient and figure of merit (ZT), making them suitable for thermoelectric applications. With ferromagnetic and half‐metallic characteristics, these compounds could be promising candidates for spintronics, thermoelectronic, and data storage applications.

Electronic structure, magnetic and adsorption properties of monolayer chromium disulfide adsorbed by (non)-metals: A first-principles study

In this paper, the changes in the electronic structure, magnetic and adsorption properties induced by the adsorption of nine nonmetals (NMs) and twelve transition metals (TMs) on the monolayer CrS2 system have been investigated in the context based on the GGA+U methodology under the density-functional theory. The corresponding energetically most stable configurations were determined by calculating the formation energies for the four high-symmetry sites of each adsorption system. The atom adsorption induces a tunable electronic structure of the system, changing the surface structure and metallic properties of the monolayer CrS2. The system is made to show a wide variety of spintronic properties, such as narrow forbidden band semiconductors and semi-metals. Magnetically, the adsorbed atoms caused the redistribution of the electronic orbitals of the system, which formed local magnetic moments of different sizes at the adsorption sites and further caused the enhancement of the total magnetic moment of the system. The atom adsorption is expected to make monolayer CrS2 a potential spintronic material, which promotes the application of this material in nanoelectronics and spintronics.