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Magnetic tunnel junctions are the core component of spintronic devices, and good magnetic tunnel junctions require high tunnel resistance, which is determined by the spin polarization of the thin films of ferromagnetic layers that make up their structure. Therefore, the design of ferromagnetic films with high spin polarization is a current research hotspot in this field. In the current study, we taken the half-metallic CrYCoAl as an object, and studied the influence of surface effect on the half-metallic behavior. Especially, we constructed the CrYCoAl (100), (110), and (111) surfaces to study their stability, electronic and magnetic properties. Results show that the YY and YAl (100) surfaces, and Co (111) surface retain the half-metallic behavior and structural stability of bulk, which provide a basis for CrYCoAl application as a thin films in magnetic tunnel junctions thus, they are likely to be used in the spintronic devices. • Stability of CrYCoAl (100), (110) and (111) surfaces are estimated by their phase diagrams. • Atomic relaxation and surface roughness are discussed. • Electronic and magnetic properties of CrYCoAl (100), (110) and (111) surfaces are studied. • The YAl and YY (100), and Co (111) termination surfaces maintain the half-metallic nature of bulk CrYCoAl. [ABSTRACT FROM AUTHOR]

[Display omitted] The effect of supercell size in the ribbon model of molybdenum disulfide edge on the cell electronic structure and specific energy was investigated, with and without spin polarization. The differences found were discussed in terms of electron count. Diagnostic criteria for the model applicability and the effect of opposite edge were discussed. [ABSTRACT FROM AUTHOR]

This paper presents a study on the electronic structure and spin properties of Transition Metal (TM) series doped Black Phosphorus (BP) using density functional theory (DFT) computations. The results indicate that the doped-Cr atom has the lowest formation energy in the BP system compared to other defects. Intrinsic defects do not induce magnetism in the BP material. However, the six types of TM atoms (Ti, V, Cr, Mn, Fe, and Ni) can lead to localized magnetic states in the system. Furthermore, researches on applying strain to the BP system have found that it will induce spin polarization in Co-doped system when applying 8% strain. Magnetic Couplings investigation demonstrate that Fe–Fe interactions exhibit ferromagnetic behavior in the BP system, with a Curie temperature above the room temperature at the d 1 or d 4 distance. These findings are significant to gain deeper insights into material spin polarization and magnetic modulation in functional materials and provide valuable references for the future development of spintronics. • The spintronic properties of transition metals doped black phosphorus were studied systematically. • The magnetic coupling between transition metals is described. • The effect of strain on the electronic structure of the system is revealed. • Our research is beneficial to the development of spintronics. [ABSTRACT FROM AUTHOR]

Monolayer SnO has attracted extensive attention due to the unique electronic properties, which have potential applications in nanoelectronic and optoelectronic devices. Transition metal (TM) atoms are often used to modulate electronic structures and magnetic properties of two dimensional (2D) materials, which can facilitate the application of these materials in spintronic devices. The electronic structure and magnetic characteristics of 3 d TM (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn) adsorbed SnO monolayer are predicted by first-principle calculations. The n -type doping in the SnO monolayer appears when Sc, Ti, V, Cr, Mn, Fe and Zn atoms are adsorbed. Co, Ni and Cu adsorptions induce the p -type doping in the SnO monolayer. In addition, the magnetic moments of SnO in the adsorption systems are in the range from −0.038 to 0.414 μ B , and that reach the maximum at the case of Ni-absorbed. It is also found that Fe, Co and Ni adsorbed SnO monolayers have a perpendicular magnetic anisotropy (PMA), while Ti, V, Cr and Mn adsorbed SnO monolayers have an in-plane magnetic anisotropy (IMA). Our results indicate that TM adsorbed SnO monolayers have the potential applications in spintronic devices. Unlabelled Image • n -Type doping in SnO monolayers appears when Sc, Ti, V, Cr, Mn, Fe and Zn are adsorbed. • Co, Ni and Cu adsorptions induce the p -type doping in SnO monolayer. • TM atoms adsorption can induce the spin polarization in monolayer SnO. • Fe, Co and Ni adsorbed SnO monolayers show perpendicular magnetic anisotropy. [ABSTRACT FROM AUTHOR]

Phosphorene's desired bandgap, high carrier mobility and weak spin–orbit coupling qualify it as an exceptional semiconductor spin channel material. These traits underscore the importance of examining phosphorene's electronic structure and that of half-metal heterojunctions (HJs) in innovating spintronic device design. This paper methodically investigates the electronic structure and Schottky barrier (SB) of a van der Waals HJ, comprising phosphorene and the half-metal Co 3 Sn 3 S 2 , subjected to biaxial mechanical strain via a first-principles method. The investigation unveils that phosphorene, as an n-type semiconductor, possesses substantial spin polarization. Remarkably, phosphorene undergoes three states – metallic, half-metallic, and semiconducting – subject to varying strain ratios (E). Furthermore, we discern that phosphorene's spin polarization, peaking at 100% for − 2 % < E < 1 % , is tunable with strain. The SB heights (SBHs) also exhibit a consistent escalation with strain: for − 5 % ≤ E < 1 % , the electron SBH is 0 eV, which increments from 0.017 eV to 0.021 eV for 1 % ≤ E ≤ 3 %. Intriguingly, the spin-down band alignment of the HJ transitions from type-II to type-I at E = 3%. Our Bader charge analysis validates that the n-doping of phosphorene is primarily due to electron acceptance from Co 3 Sn 3 S 2. The orbital hybridizations between phosphorene and Co 3 Sn 3 S 2 leads to complete spin polarization of phosphorene. Collectively, these observations confirm phosphorene's capability to attain n-type doping with 100% spin polarization. Moreover, our findings suggest the possibility to modulate both the bandgap of phosphorene and the SBHs of the HJ with strain. This highlights the potential of the phosphorene/Co 3 Sn 3 S 2 HJ in advancing the field of low-dimensional, flexible spintronics. [Display omitted] • Within the range of − 2 % < E < 1 % , phosphorene achieved 100% spin polarization. This indicates that the electron spins were aligned in a specific direction. • The SB heights of the HJ were found to be strain-dependent. The electron SB height was 0 eV for − 5 % ≤ E < 1 % , and it increased from 0.017 eV to 0.021 eV for 1 % ≤ E ≤ 3 %. • The spin-down band alignment of the HJ was identified as type-II for − 5 % ≤ E < 3 %. However, it changed to type-I at E = 3 %. [ABSTRACT FROM AUTHOR]

• The magnetism of LaFe x Ni 1- x O 3 are investigated based on the first principles. • A detail discussion of magnetic performance of FM and AFM in LaFe x Ni 1- x O 3 system. • LaFe x Ni 1- x O 3 undergoes a magnetic transition from FM to AFM when x increases to 0.5. • The magnetic moment of O atom increases with the increase of Fe doping concentration. The effect of different Fe doping concentration (x = 0.125, 0.25, 0.375 and 0.5) on electronic structure and magnetic properties of LaNiO 3 (LNO) have been performed on the spin polarization calculations based on first principles. The calculation results show that with the increase of Fe dopant concentration, LaFe x Ni 1- x O 3 undergoes a magnetic transition from ferromagnetism (FM) to antiferromagnetism (AFM). The net magnetic moments of LaFe 0.125 Ni 0.875 O 3 , LaFe 0.25 Ni 0.75 O 3 , LaFe 0.375 Ni 0.625 O 3 and LaFe 0.5 Ni 0.5 O 3 in the FM ground state are found to be 12.00 µ B /supercell, 16.00 µ B /supercell, 20.06 µ B /supercell and 23.96 µ B /supercell, respectively. In the magnetic configuration of AFM of LaFe x Ni 1- x O 3 (x = 0.125 and 0.375) with the nearest doping position, the asymmetric magnetic structure leads to the symmetry of the spin-ordered AFM network is broken, resulting in the generation of net magnetic moment of -3.06 µ B and 3.87 µ B. The net magnetic moment in LaFe x Ni 1- x O 3 mainly originates from transition metals (TM) Fe, Ni and magnetized O atoms. [ABSTRACT FROM AUTHOR]

We report a systematic experimental and theoretical study of half-metallic Heusler alloys Mn 2 V 1−x Co x Al (x = 0, 0.25, 0.5, 0.75, 1). In this study, using the arc-melting method and optimizing annealing temperatures, we succeed to synthesize Mn 2 V 1−x Co x Al (x = 0, 0.25, 0.5, 0.75, 1) alloys with evident L2 1 (or XA) order. A near compensated ferrimagnetic moment of 0.02 μB/f.u. at 5 K is observed with the Co concentration of 0.5 which is consistent with the S-P rule. In addition, we systematacially investigate the effects of Co concentration on electronic structure of Heusler alloys Mn 2 V 1−x Co x Al (x = 0, 0.25, 0.5, 0.75, 1) using first-principles calculations, and found that the half-metallic characteristic persists for all Co concentrations. In line with our experimental results, employing appropriate atomic site occupation, we obtained a full compensated ferrimagnetic moment of 0 μB/f.u. for stoichiometric Mn 2 V 0.5 Co 0.5 Al alloy. In addition, the robustness of half-metallic properties for compensated ferrimagnet Mn 2 V 0.5 Co 0.5 Al with the variation of atomic disorder are investigated and the results indicate that the Mn-Al swapping weakly destroys the half-metallic properties and the compensated ferrimagnet Mn 2 V 0.5 Co 0.5 Al alloy maintains the high spin polarization under the effect of B2 disorder. • Mn 2 V 1−x Co x Al (x = 0, 0.25, 0.5, 0.75, 1) alloys with evident L2 1 (or XA) order are fabricated successfully. • Magnetic properties can be regulated by component ratio of Co and V. • A full compensated ferrimagnetic moment of 0 μB/f.u. for stoichiometric Mn 2 V 0.5 Co 0.5 Al alloy is obtained. • Half-metallic properties of Mn 2 V 0.5 Co 0.5 Al is robust against atomic disorder. [ABSTRACT FROM AUTHOR]

Very recently, two R 3 − c Dirac half-metal materials, LaMnO 3 and MnF 3 , were found and investigated by Du et al. via first principles. They stated that these types of materials with half-metallic band structures and multiple linear band dispersions might exhibit excellent 100% spin polarization and ultrafast electron transport. However, the application of MnF 3 material in the field of spintronics is limited owing to its low Curie temperature (Tc). In this work, we proposed a new half-metal material—MnBO 3. This material satisfies two demands at the same time—it is a half-metal with a high Tc, and it has multiple nearly linear band crossings. The effects of the uniform strain, vacancies, spin–orbit coupling, as well as hole and electron doping on its electronic structures have been discussed in detail. Furthermore, to better study its specific behaviors under extreme conditions, such as high temperature or pressure, we also investigated the thermodynamic properties of MnBO 3 through the quasi-harmonic Debye model. Finally, its thermal stability at room temperature has been proved in this article by means of ab initio molecular dynamics (AIMD) simulations. We hope that MnBO 3 can attract more attention for R 3 − c -type half-metallic materials with linear band crossings and a high Curie temperature in experimental and theoretical areas. • We proposed a R 3 − c robust half-metal with multiple Dirac-like crossings. • The relatively high T c of MnBO 3 makes it more ideal for spintronic applications. • MnBO 3 is thermally stable at room temperature. • The 100% spin polarization comes from its unusual band structures. [ABSTRACT FROM AUTHOR]

Using first principles total energy calculation with the approach of density functional theory (DFT) and DFT + U calculations, the structural and electronic properties of erbium copper (ErCu) intermetallic compound were studied. In the present work, we used the local density approximation for the exchange and correlation potential for the spin polarized case. The structural optimization shows that ErCu is stable in the cubic structure. The obtained ground state properties viz; lattice constant a o (a.u), bulk modulus B (GPa) and magnetic moment (μ B), which show good comparison with the available experimental data. We have also investigated the electronic properties such as electronic band structure, density of states, Fermi surfaces and charge density of states for spin-polarized case. In the band structure, majority spins energies contributions are higher than the minority spins energies contribution. The total density of states (TDOS) show that near the Fermi level, is mostly dominated by Er 'f' orbital electrons and below the Fermi level, are due to Cu '3d' orbital electrons. The charge distributions of ErCu are ranging between +0.0003 e/Å3 to +0.0693 e/Å3 for majority channels and +0.0003 e/Å3 to +0.0715 e/Å3 for the minority spin channels. • Spin polarized data of structure and electronic properties of B2-type ErCu are reported using DFT and DFT+U. • With spin polarization, good agreement of obtained ground state properties with available data. • Majority spins energies contributions are higher than the minority spins energies contribution. • The ' f ' states of Er and ' d ' states of Cu play an important role in band structures and Fermi surfaces of ErCu. [ABSTRACT FROM AUTHOR]

• Origin of the large saturate moment at 5 K in Fe 2 MnGe DO 19 phase was determined. • Phase stability of cubic and hexagonal Fe 2 MnGe was investigated. • "Why Fe 2 MnGe DO 19 phase is stable at room temperature" was discussed. • Information on electronic structure of Fe 2 MnGe DO 19 phase was presented. The electronic structure, phase stability and magnetic properties of cubic and hexagonal type Fe 2 MnGe were investigated and compared with the well-known Heusler alloy Fe 2 MnSi. Three different structures L2 1 , DO 3 and DO 19 were considered for them. In both alloys the cubic phase (L2 1 and DO 3) has a lower total energy comparing with the hexagonal DO 19 phase at 0 K. But in Fe 2 MnGe the energy difference between the DO 19 and L2 1 phases is much smaller than Fe 2 MnSi. The DO 3 disorder can lower the stability of the cubic phase further and make the total energies of hexagonal and cubic phases closer, this can help the DO 19 phase gain stability. Finally, in Fe 2 MnGe, the energy difference is 0.12 eV/f.u., much smaller than the 0.41 eV/f.u. in Fe 2 MnSi. That is the possible reason why Fe 2 MnGe DO 19 phase can be synthesized experimentally and Fe 2 MnSi cannot. L2 1 type Fe 2 MnGe is a half-metal with 100% spin polarization and has a total spin moment of 3μ B /f.u. The spin polarization ratio of DO 3 phase is also high. But for the DO 19 hexagonal phase, a normal ferromagnetic metal character is observed. The calculated total moment for DO 19 type Fe 2 MnGe is larger than 6μ B /f.u. This total moment comes mainly from the large and parallel coupled partial spin moments of Fe and Mn. [ABSTRACT FROM AUTHOR]

Full potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT) is used to investigate the structural, electronic, magnetic and optical properties of nonstoichiometric fluoroperovskite compounds Sr 1 − x Eu x LiF 3. The Nonstoichiometric systems characterized by new physical properties are compared with the theoretically investigated cubic fluoroperovskite SrLiF 3. The modified Becke–Johnson (mBJ) exchange potential is used to calculate the band gap energy E g. The nonstoichiometric systems show spin dependent band gap characterized by very large magnetic moment in Eu sites. • Cubic fluoroperovskite SrLiF 3 shows large direct band gap (Γ−Γ). • These compounds show half metallicity behaviour in the minority density of states. • The optical properties indicate that the nonstoichiometric Sr 1−x Eu x LiF 3 compounds are assumed as light harvesters, since the Eu+2 doping increases the absorption. [ABSTRACT FROM AUTHOR]

Abstract The structural, mechanical, electronic and magnetic properties of quaternary Heusler ZrTiRhGa alloy have been investigated by using the first-principles calculations within the generalized gradient approximation GGA. The results of our calculations show that the type (I) of ZrTiRhGa, with the ferromagnetic (FM) state, is the most stable configuration among three possible configurations. The GGA + U calculations, where U is on-site Coulomb interaction correction, are performed to investigate the relationship between band gap and Hubbard potential. The calculated results showed that ZrTiRhGa compound is half-metallic material (HMM) with complete spin polarization around the Fermi level. The total magnetic moment is 2 μB per formula unit and follows the Slater-Pauling rule μt = Zt−18. The calculated elastic constants, cohesive and formation energy, for ZrTiRhGa compound, were analyzed in detail and reveal the mechanical stability. In addition, we investigated the sensitivity of the half-metallicity with two structural-type changes: hydrostatic and tetragonal deformation. Our calculations show that the half-metallicity can be preserved with lattice constants from 5.74 Å to 7.12 Å, under the influence of hydrostatic strain and in the range of the c/a ratio from −8% to 12% with the effect of the tetragonal strain. For ZrTiRhGa, since there is no available experimental data, our calculations are considered as first predictions. Highlights • The quaternary Heusler ZrTiRhGa alloy has HM nature at the equilibrium volume. • The calculated Mtot of quaternary Heusler ZrTiRhGa alloy is 2 µB, which is in agreement with Slater- Pauling rule. • ZrTiRhGa alloy maintains the HM nature when the values of lattice constant are included between 5.74 Ǻ -7.12 Ǻ. • The quaternary Heusler ZrTiRhGa alloy maintains the HM nature, in the range of the c/a ratio from 0.81 to 1.2. [ABSTRACT FROM AUTHOR]

Abstract We have investigated the reconstruction and electronic structure of divacancy in chiral and achiral graphene nanoribbons as the defect moves to the ribbon edge. The new healing bonds introduce strain dictating the structure and its energetics. Unlike in infinite graphene, the ribbons can take advantage of the edge flexibility in relieving stress. The total energy depends on the defect orientation and its distance to the ribbon edge, and the disposal of the divacancy through the edge results in the energy gains up to ≈7.7 eV. This energy gain is closely related to the pentagon count in the final edge morphology. The divacancy has lower energy near the edge, and thus it is more likely to occur at the edges in the thermodynamic equilibrium. We find that the zigzag portions at the edge induce spin polarization even though the whole edge is not zigzag. However, the spin polarization from discontinuous zigzag portions are not strong and can be modified by the spin polarization around the defect. Moving the divacancy closer to an edge modifies the spin polarization on one side, and the magnetic structure becomes diverse especially in the achiral ribbons. The divacancy induces defect states near E F. The defect level and the extent of its mixing with native ribbon states depend on the defect orientation and distance to the edge. Highlights • Properties of divacancy in graphene ribbon depend on its orientation and distance to edge. • Divacancy is likely to migrate and can be disposed from edge. • Divacancy self-heals by new bonds that create strain. • Unlike in infinite graphene, ribbons can take advantage of edge flexibility in stress relieving. • Zigzag portions at the edge induces spin polarization even if the whole edge is not zigzag. [ABSTRACT FROM AUTHOR]

Abstract The electronic structures and magnetic properties of 6H-SiC doped with N, C vacancies (V C), Si vacancies (V Si) and Al are studied by first principles calculations. The results indicate that the N substituting C in 6H-SiC cannot order magnetism but V Si can introduce magnetic moments effectively. Ferromagnetism coupling is obtained in (N, 2 V Si)-codoped 6H-SiC. The ferromagnetism can be mainly attributed to the interactions between the 2 p orbitals of C atoms around Si vacancies. More interestingly, substituting Si with Al can enhance the ferromagnetic states in 6H-SiC in neutral states. We also studied the effect of charge on magnetic properties and provide an effective method of tuning magnetism in 6H-SiC. Highlights • The doping with N Si , V Si and (N C , V Si) can induce ferromagnetism in 6H-SiC crystal. • Ferromagnetism can be enhanced by Al substituting and charge. • The spin polarization is proposed as the origin of ferromagnetism. [ABSTRACT FROM AUTHOR]

Abstract In this study, the structural and electronic properties of CoX 0.25 S 1.75 (X = F, Cl, or Br) were investigated based on spin-polarized first-principles calculations. S-F, S-Cl, and S-Br covalent bonds are not present in CoX 0.25 S 1.75 (X = F, Cl, or Br). The generalized gradient approximation (GGA) + U and Heyd-Scuseria-Ernzerhof hybrid functional method may overestimate the spin-down band gap for CoS 2. The results obtained for CoX 0.25 S 1.75 (X = F, Cl, or Br) using the GGA method are expected to be more reasonable. Only the half-metal CoF 0.25 S 1.75 can be used for spintronic applications and the metal CoX 0.25 S 1.75 (X = Cl or Br) is more suitable for use in supercapacitors. The p - d hybridization between S and Co atoms in CoF 0.25 S 1.75 is stronger compared with that in CoS 2. The p - d hybridization between S(S-X) and Co atoms is stronger whereas that between S(S-S) and Co atoms is weaker in CoX 0.25 S 1.75 (X = Cl or Br). Doping with F and Cl (Br) atoms in CoS 2 induces new bands with less and more dispersion, respectively. In CoX 0.25 S 1.75 (X = F or Cl), X atoms gain more electrons than S atoms and the charge density difference indicates that S atoms donate electrons to F and Cl atoms. However, in CoBr 0.25 S 1.75 , Br atoms gain fewer electrons than S atoms and there is almost no charge transfer between S and Br atoms. Graphical abstract Image 1 Highlights • Results obtained for CoX 0.25 S 1.75 by GGA method are expected to be more reasonable. • CoF 0.25 S 1.75 is half–metallic and can be used for spintronic applications. • CoCl 0.25 S 1.75 and CoBr 0.25 S 1.75 are more suitable for use in supercapacitors. • Doping CoS 2 with F/Cl (Br) atoms induced new bands with less/more dispersion. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Structural, magnetic and optical properties of Mg-doped CeO 2 (1 1 1) surface were investigated. • The doped CeO 2 (1 1 1) surface systems exhibit different bonding character. • The doped surface and subsurface systems result in local and scattered spin atmosphere. • The incorporation of Mg can lead to the red shift of absorption edge. Abstract The electronic structure, magnetic and optical properties of Mg-doped CeO 2 (1 1 1) surface have been investigated by first-principles calculations. In this paper, the doping case is actively favorable to process under O-rich conditions than under Ce-rich conditions. The distortion of doping systems of Mg replacing Ce of surface is larger than that of subsurface. The covalent character is getting weaker and the ionic character is gradually obvious for Mg O bond from surface to subsurface doping. The results show that the existence of defect states with O 2 p orbital character makes spin splitting, causing the local and scattered magnetic moments for surface and subsurface doping of Ce, respectively. And the 9 and 12 atomic layers doping systems exhibit magnetic ground states with different magnetic moments. In particular, the calculated Curie temperature (about 434, 483, 1200 K) is higher than room temperature (RT), therefore, the theoretical results showed that Mg-doped CeO 2 (1 1 1) thin films would can be obtained stable room temperature ferromagnetism (RTFM), which is beneficial to practical application. In addition, the optical properties show that all doped systems are capable of enhancing effective absorption of visible and near-infrared light. [ABSTRACT FROM AUTHOR]

Effect of Cr doping on the magnetic structure and electronic properties of Fe 2 VSi has been investigated by experimental measurement and first-principles calculations. In Fe 2 V 1-x Cr x Si, ferromagnetism can be stabilized with 10% Cr substitution. The Curie temperature T C increases rapidly with increasing Cr content and reaches 365K when x = 0.4. The saturation magnetization M s also increases with increasing Cr content. A small amount of A15 secondary phase is observed with increasing Cr content at x = 0.4, indicating that the solid solubility of Cr in Fe 2 VSi has been reached. In Fe 2 V 1-x Cr x Si, high spin polarization ratio is predicted when x ≥ 0.25, and half-metallic character is observed when x = 0.5, 0.75 and 1.0. The calculated total spin moment M t also increases with increasing x. When x is larger than 0.2/0.25, the experimental/theoretical total moment gets close to the Slater-Pauling curve of M = Z - 24 for half-metallic Heusler alloys. All this makes Fe 2 V 1-x Cr x Si promising candidates for spintronic applications. [ABSTRACT FROM AUTHOR]

In this paper, using first-principles calculations based on density-functional theory, the electronic structures, magnetic properties, and half-metallicity in the bulk and (001) surface of quaternary Heusler alloy CoNbMnSi are studied. For the bulk, the CoNbMnSi compound shows half-metallicity with a band gap of 0.5 eV in the down-spin direction at a equilibrium lattice constant of 5.88 Ǻ. At a similar equilibrium lattice constant, the half-metallicity confirmed in the bulk CoNbMnSi, is ruined at both NbSi- and MnCo-terminated (001) surfaces and subsurfaces. Based on the magnetic property calculations, the magnetic moments of Mn and Nb atoms at the (001) surfaces increase with respect to the corresponding bulk values, while the magnetic moment of Co and Si atoms decreases. The spin-polarization ratio clearly decreases below 75% for (001) surfaces and subsurfaces of the CoNbMnSi alloy. [ABSTRACT FROM AUTHOR]

On the basis of first principles calculations, the electronic structures and magnetic properties of quaternary Heusler alloys RbCaNZ (Z = O, S, and Se) were studied. The negative formation energies indicated that all these compounds were thermodynamically stable and thus may be experimentally synthesized at appropriate conditions in the future. The results showed that Y I structure was the most favorable configuration among the three possible structures. All compounds were found to be half-metallic ferromagnets. The characteristic of energy bands and origin of half-metallicity were also verified. The total magnetic moments of RbCaNZ (Z = O, S, and Se) compounds were obtained 2 μ B per formula unit, which were in an agreement with Slater-Pauling rule ( M tot = 12  −  Z tot ). Half-metallicity was preserved at ranges of 5.06–8.36 Å, 5.96–8.81 Å, and 6.13–8.73 Å for RbCaNO, RbCaNS, and RbCaNSe compounds, respectively, which show that these quaternary Heusler compounds may be potential candidates in spintronic applications. [ABSTRACT FROM AUTHOR]

The electronic, magnetic and optical properties of C- and N-doped CeO 2 bulk and (111) surface have been systematically investigated by first-principles calculations. The results show that the spin splitting occurs when doping atoms replace the anion sites in the CeO 2 matrix, causing a local magnetic moment of 2.00, and 1.00 μ B for C- and N-doping, respectively. The strong hybridization between dopants 2 p and O 2 p triplet-states around the Fermi level gives rise to the half-metallic character for doped bulk systems, while substitution onto the surface eliminates the degeneration of dopants 2 p orbitals, which results in anisotropic spin atmosphere. Especially, owing to the low formation energy and available RTFM, N-doped CeO 2 would be easily realized in the experiment and should also be wonderful candidate materials for oxide spintronics. In addition, compared with N-doped CeO 2 , the calculated optical properties reveal that C-doped CeO 2 (111) surface is able to enhance the absorption of the visible light. [ABSTRACT FROM AUTHOR]

We performed a systematic study of the electronic structures and magnetic properties of SnS 2 monolayer doped with non-magnetic elements in groups IA, IIA and IIIA based on the first-principles methods. The doped systems exhibit half-metallic and metallic natures depending on the doping elements. The formation of magnetic moment is attributable to the cooperative effect of the Hund's rule coupling and hole concentration. The spin polarization can be stabilized and enhanced through confining the delocalized impurity states by biaxial tensile strain in hole-doped SnS 2 monolayer. Both the double-exchange and p-p exchange mechanisms are simultaneously responsible for the ferromagnetic ground state in those hole-doped materials. Our results demonstrate that spin polarization can be induced and controlled in SnS 2 monolayers by non-magnetic doping and tensile strain. [ABSTRACT FROM AUTHOR]

Co 2 CrAl/GaAs slabs have been constructed to study the electronic structure and magnetic properties by Structeditor program implemented in WIEN2k Code. GGA and LDA parameterizations have been used for exchange correlation functions. The density of states, structure and magnetic parameters have been studied and analyzed. Co 2 CrAl/GaAs (1 1 1) surface shows 80% spin polarization within LDA parameterizations. Variation in spin polarization with varying projections is observed due to different surface terminations and bond length. Effect of capping layers of Au and Cu on the magnetic moment and spin polarization of Co 2 CrAl/GaAs for different surface projections has been studied. The DOS indicates that the spin polarization has enhanced for all surface projections within the GGA approximation for both capping layers. The magnetic moment also varies from the bulk value of 3µ B in Co 2 CrAl/GaAs surfaces. [ABSTRACT FROM AUTHOR]

A new prototype tunnel junction with AgBr based barrier is proposed in this study. Electronic and magnetic properties of Fe/AgBr/Fe (001) heterostructures are investigated on the basis of first-principles and ballistic conductance calculations. The interlayer exchange coupling and electronic transport properties are analyzed as functions of the AgBr barrier thickness. The results show that Fe magnetism at Fe/AgBr (001) interfaces is enhanced as compared with the bulk material. A very strong direct tunnelling of Fe Δ 1 states is observed. The minority-spin channel is characterized by resonant tunnelling of interfacial states that are forming at Fe/AgBr (001) interfaces. Spin-polarization of the tunnelling current is positive and can exceed 99%. Tunnelling magnetoresistance ratios of about 8000% are evidenced for the junctions with clean interfaces. Fe/AgBr (001) coherent interfaces could act as nearly ideal symmetry-filters. In the presence of interfacial disorder the tunnelling magnetoresistance ratios decrease dramatically. The exchange coupling between Fe electrodes oscillates as a function of the barrier thickness. [ABSTRACT FROM AUTHOR]

The mechanical, structural, electronic and magnetic properties of s -triazine sheet ( C 6 N 6 ) with embedded Mn atom ( Mn – C 6 N 6 ) is investigated under the influence of external environment (symmetric deformation and perpendicular electric field) using density-functional theory (DFT) with the spin polarized generalized gradient approximation (GGA) and Hubbard U correction ( GGA + U ). Our results show that Mn – C 6 N 6 system is structurally and mechanically stable. The binding energy of Mn embedded in C 6 N 6 sheet can be modulated under the influence of external environment. Moreover, the semiconducting and magnetic properties of the Mn – C 6 N 6 systems under external fields are preserved. We also explore the geometries, electronic and magnetic properties of Mn – C 6 N 6 with adsorbed atoms and molecules. The Mn – C 6 N 6 with adsorbed O atom and O 2 molecule systems shows half-metallic character whereas the remaining systems preserve their semiconducting property. The total magnetic moment per unit cell in most of the systems is found to reduce as compared to that of the Mn – C 6 N 6 sheet. The reduction in the magnetic moment can be related to the strong interactions among the Mn atom and the surrounding atoms which lead to the formation of low-spin configurations. Overall, our results indicate that the Mn – C 6 N 6 systems with and without adsorbed atoms and molecules can serve as potential candidates for future spintronics and catalysis applications. [ABSTRACT FROM AUTHOR]

Atomic and electronic structure of LSMO-based composites with carbon nanotubes were studied by means of density functional theory with respect to the termination of LSMO surface. The deformation of the tubes caused by the lattice mismatch with the substrate leads to a major change in their electronic structure. The surface terminated with Mn-O layer provides much stronger interaction with carbon nanotubes than Sr-O terminated one does. The interaction with transition metal atoms is essential for spin polarization of the nanotube while no spin injection was observed for Sr-O-supported tubes. [ABSTRACT FROM AUTHOR]

According to electronic structure calculations based on density functional theory, we predicted and studied the structural, mechanical, electronic, magnetic, and transport properties of a new full Heusler chalcogenide called Fe 2 CrTe in both its bulk and heterostructure forms. This system exhibits ferromagnetic and half-metallic (HM)-like behavior, with very high (about 95%) spin polarization at the Fermi level in its cubic phase. Interestingly, under tetragonal distortion, a clear minimum (with almost the same energy as the cubic phase) was found at a c/a value of ∼ 1.26, but it exhibits ferrimagnetic and fully metallic characteristics. The compound was found to be dynamically stable against lattice vibration in both phases. The elastic properties indicate that the compound is mechanically stable in both phases according to the stability criteria for the cubic and tetragonal phases. The elastic parameters demonstrate the mechanically anisotropic and ductile nature of the alloy system. Due to the HM-like behavior of the cubic phase and considering practical aspects, we probed the effect of strain and the substrate on various physical properties of the alloy. The transmission profile was calculated for the Fe 2 CrTe/MgO/Fe 2 CrTe heterojunction to investigate its possible use as a magnetic tunneling junction material in both the cubic and tetragonal phases. A large tunneling magnetoresistance ratio of ≈ 1 0 3 % was determined for the tetragonal phase and it was one order of magnitude larger than that for the cubic phase. • We predict a novel full Heusler chalcogenide - Fe 2 CrTe. • It shows a ferromagnetic and half-metal(HM)-like behavior in the cubic phase. • Volume conserved tetragonal phase exhibits ferrimagnetic and metallic nature. • Dynamical and mechanical stability are predicted in both the phases. • Under negative uniform strain, cubic phase shows fully HM-like behavior. • Promising spin-transport properties for Fe 2 CrTe/MgO/Fe 2 CrTe is observed. [ABSTRACT FROM AUTHOR]

Employing first principles calculations within the Density Functional Theory, the influence of Se dopants on electronic structure, magnetic and optical characteristics of CoNiFe 2 O 4 (CNFO) spinel ferrites (SFs) is elucidated. The role of Se dopants replacing the O atoms in the supercell is revealed by means of spin-asymmetric density of states, magnetic moment, and optical spectra. The findings suggest that electronic structure, magnetism and optical properties are determined by both Se content and atomic arrangment due to doping sites. It is shown that the energy band gap declines with increasing Se concentration and that, based on site occupation, a half metallic characteristic can be achieved. An appreciable spin polarization and relevant data on optical characteristics demonstrate that Se doped CNFO SFs are promising candidates for prospective spin dependent applications and visible light photocatalysis. [ABSTRACT FROM AUTHOR]

• The monovacancies (MVs) in Bi monolayer can lead to a transformation from semiconductor to metallicity. • A particular defect configuration can give rise to a spin polarization and room-temperature ferromagnetism. • The physical property difference in Bi monolayer is strongly dependent on defect types. Bismuth (Bi) monolayers have attracted much attention due to their intriguing physical and chemical applications, which are strongly related to the existence of topological defects. However, the intrinsic correlation between the defect types and particular electronic structures of Bi monolayers still needs to be understood. Herein, we intentionally implanted various typical topological defects into Bi monolayers to reveal the differences in the electronic structure, in which the monovacancies (MVs) can lead to a transformation from a semiconductor to a metal. More interestingly, a particular defect configuration can give rise to a spin polarization and room-temperature ferromagnetism, demonstrating the spintronic applications. This work reveals that the physical property differences of Bi monolayers are strongly dependent on their defect types. The topological defects can be intentionally implanted into Bi monolayer to achieve the transformation from semiconductor to metallicity, or a spin polarization and room-temperature ferromagnetism as well. [Display omitted] [ABSTRACT FROM AUTHOR]

The effects of 3 d transition metals doping on the structural, electronic, and magnetic properties of aluminum hydride were investigated based on spin-polarized first-principles calculations. The studies indicated that V, Cr, Mn, and Fe doping could produce polarization of high-spin state, while Co and Ni doping would induce polarization of low-spin state. It was found that the magnetic ground state depended on the distance between two substitutions and the long-range ferromagnetic coupling was achieved upon doping V, Mn, and Fe. The present work indicated that the introduced 3 d -block dopants could tailor aluminum hydride into either a potential half-metallic or n -type magnetic semiconductor by tuning the valence electrons of the impurities. The main findings of this work pointed out the possibilities of the applications of hydrides in future hydride electronics and spintronics. [ABSTRACT FROM AUTHOR]

Investigation of band structure and thermo-physical response of new quaternary CoVTiAl Heusler alloy within the frame work of density functional theory has been analyzed. 100% spin polarization with ferromagnetic stable ground state at the optimized lattice parameter of 6.01 Å is predicted for the compound. Slater-Pauling rule for the total magnetic moment of 3 µ B and an indirect semiconducting behavior is also seen for the compound. In order to perfectly analyze the thermo-physical response, the lattice thermal conductivity and thermodynamic properties have been calculated. Thermal effects on some macroscopic properties of CoVTiAl are predicted using the quasi-harmonic Debye model, in which the lattice vibrations are taken into account. The variations of the lattice constant, volume expansion coefficient, heat capacities, and Debye temperature with pressure and temperature in the ranges of 0 GPa to 15 GPa and 0 K to 800 K have been obtained. [ABSTRACT FROM AUTHOR]

Density functional theory calculations were carried out to investigate how single-atom vacancies affect the electronic and magnetic properties of three types of graphyne model systems. Our simulations demonstrate that a single-atom vacancy can lead to an in-plane structural rearrangement, which plays an important role in tuning the electronic structures. A dispersionless spin-polarized band was observed around the fermi level, inducing strong magnetism in the three graphyne models. The single-atom vacancy can induce a 1.1–1.3 μ B magnetic moment into αGy and βGy, while this value increases significantly to about 1.8μ B for γGy. This single-atom vacancy technique is a promising method of manipulating the electronic and magnetic properties of graphyne. [ABSTRACT FROM AUTHOR]

We explored the influence of the inclusion of spin polarization on the energy band gap of β-RbSm(MoO 4 ) 2 . Calculations explored that the appearance of Sm-4f states at the conduction band minimum (CBM) of the spin-up case causes a significant influence on ground state properties of β-RbSm(MoO 4 ) 2 . The total and partial densities of states confirm the existence of Sm-4f states in the CBM of the spin-up case. The partial densities of states exhibit a strong hybridization between some states which may lead to the formation of covalent bonds. The valence band maximum (VBM) and the CBM are located at the center of first Brillouin zone (Γ), resulting in a direct band gap for both of majority spin (↑) and minority spin (↓). The values of the band gap are 3.01 eV (↑) and 3.78 eV (↓). The all-electron full potential linear augmented plane wave (FPLAPW+lo) method within the generalized gradient approximation plus the Hubbard Hamiltonian (GGA+U) were used. We have applied U on 4 f orbital of Sm atoms and 4 d orbital of Mo atoms. We have taken a careful look at the electronic charge density distribution to visualize the charge transfer and the chemical bonding characters. The calculated bond lengths show very good agreements with the measured ones. The optical properties were calculated to seek a deep insight into the electronic structure. It has been found that below λ = 450 nm β-RbSm(MoO 4 ) 2 exhibits a positive uniaxial anisotropy, while at λ = 450 nm and above, the crystal exhibits a negative uniaxial anisotropy. [ABSTRACT FROM AUTHOR]

Ab initio calculations of the electronic and magnetic properties of FeRh/MgO (001) interface are reported, focusing on the effects of different atomic terminations. It was found that the Fe-O termination is energetically the most stable. The change in the electronic properties at the interface is analyzed using the spin-polarized layer projected density of states, which shows that the spin polarization at the Fermi level is dominated by the spin-down t 2 g states. However, the magnetic moment of the interfacial Fe atom is not enhanced significantly compared to that of the inner layers. The difference of total energy between antiparallel (AP) and parallel (P) alignments of the magnetizations of the FeRh electrodes as function of MgO thickness shows that the AP configuration is the most stable and this interlayer exchange coupling decreases exponentially as predicted by the free-electron theory. Finally, Löwdin analysis of the electron density shows that the charge is transferred from the interface MgO layer to that of FeRh and confirm the change of the interface states at the vicinity of the Fermi level. [ABSTRACT FROM AUTHOR]

First-principles calculations in combination with group theory analyses were employed to study the spin-polarized electronic structures of C B V N centers consisting of a nitrogen vacancy and a substitutional carbon atom in hexagonal boron nitride ( h -BN) monolayer with different charge states. It is clarified that the paramagnetic neutral C B V N center is stable in the n -type h -BN monolayer. The neutral defect center possesses a triplet (S = 1) ground state and with two spin-conserved optical vertical transition. Its spin coherence time is estimated to be 3.9 ms at T = 0 K by a simple scheme combining the mean-field theory and the first-principles calculations. The results indicate that the neutral C B V N center is very suitable for achieving spin qubit. [ABSTRACT FROM AUTHOR]

The electronic structure and magnetic property of Mn 2 Co 1−x Cr x Al (x = 0.25, 0.5, 0.75) have been investigated based on density functional theory calculations. The results indicate that both Mn 2 Co 0.75 Cr 0.25 Al and Mn 2 Co 0.25 Cr 0.75 Al are half metals with a half-metallic gap of 0.07 eV and 0.08 eV, respectively. In addition, Mn 2 Co 0.75 Cr 0.25 Al can maintain the half-metallicity even when the crystal structure is disordered, while the half-metallicity of Mn 2 Co 0.25 Cr 0.75 Al is destroyed once the disorder appears. For Mn 2 Co 0.75 Cr 0.25 Al, the half-metallic gap of the Cr-Co disordered structure is 0.14 eV, suggesting a great potential to be a good candidate for spintronic application. [ABSTRACT FROM AUTHOR]

The interfacial interaction between graphene and ferromagnetic substrate is known to bring additional controls to the intrinsic properties of graphene, in addition to inducing some novel properties to the system which may have potential application in spintronics. In this work the spin-polarized electronic structures across the graphene–ferromagnet interface has been investigated using first principles density functional theory calculation as it is implemented on Vienna ab-initio simulation package (VASP). The electronic and magnetic properties of the interface have also been investigated. The ferromagnet substrate was represented by N i (111) and C o (111) surfaces due to their structural resemblance to graphene. The study reveals that the ferromagnet layers adjacent to the interface show a transition of spin orientation from in plane to out of plane. The critical thickness of the slab which yields the maximum shifting of the spin orientation of the ferromagnet layers is also determined. The strong hybridization between different orbitals of graphene and ferromagnet significantly affects the electronic and magnetic properties of the interface. Reduction on the local magnetic moments of the ferromagnet layers adjacent to the interface and the induced spin polarization on the graphene layer were also observed which is due to the impacts of the hybridization. This work will provide important information which can be used for efficient design of interfaces for graphene-based spintronics. [ABSTRACT FROM AUTHOR]

This work reports an experimental and theoretical investigation of pure, Sr, and (Sr,Co) co-doped CdS systems. Pure and co-doped CdS nanostructure thin films were grown with varying Co doping concentrations by sol-gel spin coating method. X-ray diffractograms of the films reveal that the films grow along (002) plane and the crystallites sizes were about ∼3–6 nm. The band gaps of the films were obtained in order of 2.30–2.48 eV and a blue shift in the band gap with co-doping was observed in comparison with Sr:CdS system. In addition, pure and co-doped CdS system were also investigated via density functional theory. Initially, pure and co-doped CdS systems were optimized using WIEN2k software based on density functional theory. The calculated optical properties and band gap reveal a close agreement with the experimental results. The (Sr,Co) co-doped CdS shows the spin polarization effect on the valence band which makes this materials suitable for optoelectronics and spintronics applications. [ABSTRACT FROM AUTHOR]

In this study, density functional theory (DFT) showed that the electronic band profiles of CaCu 3 B 2 Re 2 O 12 (B = Mn, Fe, Co, and Ni) indicate their half-metallic character. The optimized magnetic energy curves in different magnetic phases demonstrated the type-I ferrimagnetic order of all the compounds investigated in this study. The magnetic exchange coupling constants were calculated between the Cu–B, B–Re, and Cu–Re site spins using the Heisenberg model. These interactions generate strong long range Cu(↑)B(↑)Re(↓) order through a super-exchange mechanism. In these perovskites, the anti-parallel moments of Re with B and Cu reduce the net magnetic moments and they are responsible for the ferrimagnetism. The Cu and B 3d-electrons are localized and responsible for the magnetism, and the Re 5d-electrons are delocalized and responsible for the metallic nature. Magnetic susceptibility analysis verified the results estimated using DFT and the Heisenberg model. Due to the 100% spin polarization around the Fermi level, high Curie temperature TC and ferrimagnetism are expected, thereby making these materials suitable for spintronic applications. • The half-metallic character of the CaCu 3 B 2 Re 2 O 12 (B = Mn, Fe, Co and Ni) was revealed by DFT. • Heisenberg model was used for the calculating of the magnetic exchange coupling constants. • It has been shown the perspectives of the CaCu 3 B 2 Re 2 O 12 (B = Mn, Fe, Co and Ni) in spintronic applications. [ABSTRACT FROM AUTHOR]

First principles calculations are adopted to study the spin polarization properties of thiophene molecule which adsorbed at the Co, Fe, and Ni electrode surfaces. The density of states, spin-polarized density distributions as well as the differential charge density distributions are obtained. It is found that the p orbital of the thiophene molecule will interact with the d orbital of the ferromagnetic electrodes, which will generate new spin coupling states and lead to obvious spin polarization in the thiophene molecule. Different electrodes induce different spin polarization properties, and in which the Fe electrode will bring the biggest spin polarization of the thiophene molecule. People can selectively and efficiently inject spin polarized electrons into molecules by choosing suitable ferromagnetic electrodes in organic spintronic devices. [ABSTRACT FROM AUTHOR]

We studied the electronic structure of thin Ni films grown on a W(110) single crystal, as a function of the Ni thickness, by means of angle-resolved photoemission and inverse photoemission spectroscopy, also with spin resolution. The results are discussed in the light of the different stages characterizing the transition from the pseudomorphic bcc to the fully relaxed fcc phase. A clear spin polarization is detected as soon as a bulk-like electronic structure is observed. In these conditions, we characterized the exchange splitting of the occupied bands at the Γ ¯ and M ¯ points of the surface Brillouin zone, providing further experimental support to previous interpretations of photoemission spectra from bulk Ni. [ABSTRACT FROM AUTHOR]

Diverse electronic structures can be achieved by N-substitution in stable two-dimensional dumbbell carbonitrides. [Display omitted] • A new structure, the DB-C structure, is proposed based on the dumbbell structure predicted in group-IV (Si, Ge, and Pb) monolayer. • Different kinds of DB-C x N y are formed by substituted doping of the C atoms at the bulged site with different amount of N atoms in the DB-C structure. • DB-C 4 N-1 and DB-C 4 N-2 hold the Dirac electronic state with a gap-opening under the influence of spin–orbit coupling. • The DB-C 7 N 3 monolayer is a bipolar magnetic semiconductor. The two-dimensional carbonitrides (C x N y) are attractive materials and their diversified properties play an important role in various fields. In this paper, a dumbbell C x N y is proposed. As graphene is a zero band-gap semiconductor with Dirac cone, while the DB-C monolayer formed by adding C atoms to graphene is an indirect-gap semiconductor with a band-gap of 1.69 eV. The various DB-C x N y are formed by substituted doping of the C atoms at the bulged site with different amount of N atoms. There are four bulged C in a unit cell of DB-C. DB-C 9 N has a metallic behavior, evolved by n-type doping. DB-C 4 N-1 and DB-C 4 N-2 hold the Dirac electronic state with a gap-opening under the influence of spin–orbit coupling, while DB-C 4 N-3 is an indirect-gap semiconductor. Of all DB-C x N y , only DB-C 7 N 2 and DB-C 7 N 3 are magnetic, but DB-C 7 N 2 has a metallic behavior and DB-C 7 N 3 is a bipolar magnetic semiconductor with controllable spin polarization. DB-C 6 N 4 is a nonmagnetic semiconductor with a direct band-gap of 0.80 eV. The stability of all DB-C x N y monolayers is verified by the phonon spectrum. Due to the unique geometric structure, tunable electronic properties, and high specific surface area, DB-C x N y monolayers may be well applied in photocatalysis, electrocatalysis, spintronic and energy storage devices. [ABSTRACT FROM AUTHOR]

Using density functional theory calculations, the effects of various point defects, including indium vacancy (V In) and europium doping (Eu In), on the crystal structure, electronic structure and magnetic properties of Eu-doped In 2 S 3 have been investigated. The magnetic origin of the system, especially the contribution of each atomic orbit, is analyzed through the state density of spin polarization. The total magnetic moment of Eu In , V In and Eu In + V In systems are 0.267, 1.900 and 2.063 μB, respectively. Our results show that the introduction of Eu doping and In vacancy defects induce impurity energy levels. This impurity band is mainly formed by Eu-4f orbitals, which are also spin polarised and hybridised with S-3p orbitals. The calculated defect formation energies of Eu In , V In and Eu In + V In systems are −12.30, 1.67 and −4.05 eV, respectively. This work provides theoretical guidance for designing unique spintronic materials, which can promote the development of spintronic applications. [Display omitted] • The introduction of rare earth Eu3+ defect impurities can reduce the defect formation energy of the system. • The increase of In vacancy concentration can induce the enhancement of the magnetic properties of the system. • The doping Eu and In vacancy can influence the redistribution of S-3p electron orbitals • The calculated formation energy is negative, indicating that the impurity into host is relatively unproblematic. [ABSTRACT FROM AUTHOR]

The effect of single vacancy on the structural, electronic and magnetic properties of monolayer graphyne is investigated by the first-principles calculations. The calculated results reveal that single vacancy can result in the spin polarization in monolayer graphyne and the spin polarization is sensitive to local geometric structure of the vacancy. In the case of monolayer graphyne with one single vacancy at the sp 2 hybridized C site, the vacancy introduces rather weakly spin-polarized, flat bands in the band gap. Due to the localization nature of the defect-induced bands, the magnetic moment is mainly localized at the vacancy site. As for the monolayer graphyne with one single vacancy at the sp hybridized C site, one defect-induced state which is highly split appears in the band gap. The spin-up band of the defect-induced state is highly dispersive and shows considerable delocalization, suggesting that the magnetic moment is dispersed around the vacancy site. The above magnetization in monolayer graphyne with one single vacancy is possibly explained in terms of the valence-bond theory. [ABSTRACT FROM AUTHOR]

Based on density functional theory electronic and magnetic structure characterizations an unusual onset of spin polarization of p states is demonstrated leading to a stable ferromagnetic order within a carbon layered honeycomb-like compound. Specifically structural relaxation of formerly studied C 2 N in 3D network and devised here in 2D layered AlB 2 -type derived structure shows that the resulting ordered compound maintains the hexagonal crystal symmetry with an exceptionally large c/a ratio leading to strong localization of N states along c and letting magnetization develop within N-p z orbitals with 1.1 μ B per formula unit. Anisotropic antibonding interactions between C and N layers allow interpreting the results. The compound is energetically characterized in ferromagnetic ground state versus less stable anti-ferromagnetic order. [ABSTRACT FROM AUTHOR]

We investigate the electronic structures and magnetic properties of RbSe and CsTe compounds in CsCl, RS and ZB structures by using density functional theory calculation. It is shown that these two compounds exhibit half-metallic ferromagnetism with an integer magnetic moment of 1.00 μ B per formula unit in all the three structures. Total energy calculations indicate the CsCl phase is more stable than the other two phases. We investigate these two compounds with CsCl structure in detail. The ferromagnetism results mainly from the spin-polarization of p states of anion Se (Te) for the two compounds. [ABSTRACT FROM AUTHOR]

This paper presents a study on the adsorption of alkali and alkaline-earth metal atoms on single-layer stanene with different levels of coverage using first-principles plane wave calculations within spin-polarized density functional theory. The most favorable adsorption site for alkali atoms (Li, Na, K) were found to be the hollow site similar to other group IV single-layers, but the case of alkaline-earths on stanene is different from silicene and germanene. Whereas Mg and Ca are bound to stanene at hollow site, the bridge site is found to be energetically favorable for Be adatom. All adsorbed atoms are positively charged due to the charge transfer from adatom to stanene single-layer. The semimetallic bare stanene become metallic except for Be adsorption. The Beryllium adsorption give rise to non-magnetic semiconducting ground state. Our results illustrate that stanene has a reactive and functionalizable surface similar to graphene or silicene. [ABSTRACT FROM AUTHOR]

In this study, density functional theory based ab-initio calculations are utilized to investigate the electronic and magnetic properties of new series of Half Heusler FeVX (where X=Si, Ge, Sn) compounds. We have considered the C1 b -type structure of these materials in three atomic configurations, termed as α, β, and γ phases, in order to find the most stable geometric structure. The structural properties of all three phases have been determined and the effect of spin-polarization has been studied. Our calculated electronic properties suggest that the studied materials under study are half-metallic (HM) ferromagnets and stable in the α-phase. We have also employed the modified Becke–Johnson (mBJ) local spin density approximation functional for a better description of the HM response of FeVX materials. We have also shown that the HM nature of FeVX compounds is robust for a wide range of lattice constant, making these materials suitable for spintronic applications. [ABSTRACT FROM AUTHOR]

A novel design of high-voltage compatible polarimeter for spin-resolved hard X-ray photoelectron spectroscopy (Spin-HAXPES) went into operation at beamline BL09XU of SPring-8 in Hyogo, Japan. The detector is based on the well-established principle of electron diffraction from a W(001) single-crystal at a scattering energy of 103.5 eV. It's special feature is that it can be operated at a high negative bias potential up to 10 kV, necessary to access the HAXPES range. The polarimeter is operated behind a large hemispherical analyzer (Scienta R-4000). It was optimized for high transmission of the transfer optics. A delay-line detector (20 mm dia.) is positioned at the exit plane of the analyzer enabling conventional multichannel intensity spectroscopy simultaneously with single-channel spin analysis. The performance of the combined setup is demonstrated by the spin-resolved data for the valence-region of a FeCo functional layer of a tunneling device, buried beneath 3 nm of oxidic material. The well-structured spin polarization spectrum validates Spin-HAXPES in the valence energy range as powerful method for bulk electronic structure analysis. The spin polarization spectrum exhibits a rich structure, originating from clearly discernible transitions in the majority and minority partial spin spectra. [ABSTRACT FROM AUTHOR]

Based on first-principles spin-polarized density functional theory calculations, the electronic structures, and magnetic properties of Cu and Zn-doped BiFeO 3 are investigated. The calculated formation energies show that Cu prefers to occupy Fe site, while the Zn prefer to occupy Bi site. All the doped BiFeO 3 systems turn out to be favorable for G-type antiferromagnetic arrangement. The substitution of Cu and Zn for Fe produces a magnetic moment of 3.0 and 4.0 μ B per dopant, respectively. The net magnetic moments are from the broken symmetry of the AFM spin ordering network. For the substitution of Cu and Zn for Bi, the net magnetic moment originates from Cu/Zn itself and hole introduced by Cu/Zn. Two-Cu/Zn-doped cases show various magnetic behaves. If O vacancy is far away from dopants, the O vacancies don't affect the net magnetic moment of the substitution of Cu and Zn for Fe, but have notable effect for Bi site doping. The O vacancies result in metallicity in all doped cases. Our study demonstrates that the nonmagnetic Cu and Zn doping will lead to the diversity and complexity of magnetic properties depending on doping sites, distance between dopants, intrinsic defect, and so on, which could be responsible for the observed various magnetic behaviors in Cu/Zn-doped BiFeO 3 samples. [ABSTRACT FROM AUTHOR]

Electronic structure of ultrathin Ag films on Si(111) is investigated with spin- and angle-resolved photoemission spectroscopy using unpolarized light. Photoelectrons leaving d states of Ag reveal spin polarization with the polarization vector parallel to the sample surface. The effect is observed for the Ag films which have bulk-like crystallographic structure with coverages down to 1 monolayer, for Ag wetting layer on Si(111)-(7 × 7) and Si(111)- ( 3 × 3 ) Ag surface. It is found that the polarization magnitude increases with Ag thickness. The observed changes have been attributed to the changes in the Ag film morphology. [ABSTRACT FROM AUTHOR]