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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 The spin-phonon interaction is the dominant process for spin relaxation in Si, and as thermal transport in Si is dominated by phonons, one would expect spin polarization to influence Si's thermal conductivity. Here we report the experimental evidence of just such a coupling. We have performed concurrent measurements of spin, charge, and phonon transport in p-doped Si across a wide range of temperatures. In an experimental system of a free-standing 2 μm p-Si beam coated on one side with a thin (25 nm) ferromagnetic spin injection layer, we use the self-heating 3ω method to measure changes in electrical and thermal conductivity under the influence of a magnetic field. These magneto-thermal transport measurements reveal signatures in the variation of electrical and thermal transport that are consistent with spin-phonon interaction. Raman spectroscopy measurements and first principle's calculations support that these variations are due to spin-phonon interaction. Spin polarization leads to softening of phonon modes, a reduction in the group velocity of acoustic modes, and a subsequent decrease in thermal conductivity at room temperature. Moreover, magneto-thermal transport measurements as a function of temperature indicate a change in the spin-phonon relaxation behavior low temperature. Highlights • We observe spin-phonon interactions mediated magneto-thermal transport behavior in Si. • The transport measurements are supported by Raman spectroscopy and simulations results. • The magneto thermal transport measurements are carried out using self-heating 3 omega method. [ABSTRACT FROM AUTHOR]

We theoretically investigate the effect of the Rashba interaction on the conductance as well as the valley and spin polarization in an 8- Pmmn borophene superlattice by solving the Dirac–like equation and using the transfer matrix approach. The valley and spin-dependent conductance and spin polarization are effectively controlled by changing the direction of superlattice. The number of the quantum electrostatic potential plays an essential role in quantum transmission properties. Furthermore, in such a superlattice, the conductance of the electrons with spin rotation can be easily adjusted by the Rashba strength, direction of superlattice and electrostatic potential. Thus, borophene superlattice with Rashba interaction can act as a spin and valley splitter. Our work provides a new structure for spin-flip and can be useful for future spintronics and valleytronics applications. • We study the spin-dependent transport properties in an 8- Pmmn borophene superlattice. • Spin rotation can be easily adjusted by Rashba strength and electrostatic potential. • The borophene superlattice under RSOI can use as a spin-converter. • The valley polarization depends sensitively on the number of the barriers. • Magnitude and sign of spin polarization can be adjusted by direction of superlattice. [ABSTRACT FROM AUTHOR]

The density functional theory (DFT) studies are made to calculate the electronic, magnetic, and transport characteristics of potassium lanthanide KXO2 (X = Pr, Nd, and Pm) oxides have been studied by using the WIEN2K code. Perdew Burke Ernzerhof-Generalized Gradient approximation (PBE-GGA) is used for the exchange-correlation energy of the crystal structures in the hexagonal phase. However, the volume-optimized graphs depict that these compounds are energetically stable in the ferromagnetic state. Moreover, the studies of the spin-up channels of the band structure and density of states (DOS) reveal their metallic behavior whereas semiconductor nature has been noticed through spin-channels. Therefore, studied materials have half metallicity nature with 100% spin polarization at the Fermi level (EF). Total and partial magnetic moments of KXO2 (X = Pr, Nd, and Pm) and individual atoms exist due to unpaired 4f electronic states of the lanthanide ions, present at the EF. The energy difference between anti-ferromagnetism and ferromagnetism versus the volume optimization curve gives the curie temperature (Tc). The volume optimization curves show a flat region where both magnetic states have similar energies. This means the material can exist at the equilibrium volume in either state. Finally, thermoelectric properties are calculated by the BoltzTraP code. Our results unveil that these potassium-based lanthanide oxides are potential materials for devising spintronics devices and lifting future practical applications. • Studied materials have half metallicity nature with 100% spin polarization at E F. • Total and partial magnetic moments of KXO 2 and individual atoms exist due to unpaired 4 f states of La. • Energy difference between anti-ferromagnetism and ferromagnetism energy vs volume optimization curve gives value of T C. • The figure of merit is higher for KPmO2, KNdO2 as compared to KPrO2. [ABSTRACT FROM AUTHOR]

The spin resolved electronic transport behavior of ZnO nanowires (ZnONWs) linked to electrodes is investigated using first principles calculations within Density Functional Theory incorporating the Hubbard (U) term. A defect (resulting from Zn vacancy) in ZnO, as well as the use of Ni electrodes, have a significant influence on the electronic structure properties. They improve the magnetic moment of the system and generate a spin-asymmetric spectra. The ZnONWs linked to the Ni electrodes are probed for spin resolved differential conductance and current. Although the spin down differential conductance curves have a similar trend, the variations in spin up conductance are dissimilar. ZnONW-based devices appear promising for prospective spintronic applications due to their nearly half-metallic behavior around the Fermi energy and acceptable spin polarization in current. • ZnO nanowires are promising for spintronic applications. • The magnetism in ZnO nanowire-based devices can be enhanced using a vacancy and/or Ni electrodes. • Spin polarization in current and DOS is appreciable. [ABSTRACT FROM AUTHOR]

The magnetic properties of nonmetal (NM) doped (H, B, C, Si, N, P, As, O, S, Te, F, Cl, Br or I) monolayer MoSe 2 were investigated by first principle calculations. We have found that NM dopants with odd number of valence electrons can induce magnetism; on the contrary, NM dopants with even number of valence electrons cannot induce magnetism. More importantly, half metallic property has been found for H-, B-, F-, Cl-, Br- and I-doped MoSe 2 , characterized with 100% spin-polarization around the Fermi level. This work has important guidance for the realization of spin devices on monolayer MoSe 2 . [ABSTRACT FROM AUTHOR]

Quantum transport properties and spin polarization in hexagonal graphene nanostructures with zigzag edges and different sizes were investigated in the presence of Rashba spin-orbit interaction (RSOI). The nanostructure was considered as a channel to which two semi-infinite armchair graphene nanoribbons were coupled as input and output leads. Spin transmission and spin polarization in x, y, and z directions were calculated through applying Landauer-Buttiker formalism with tight binding model and the Green's function to the system. In these quantum structures it is shown that changing the size of system, induce and control the spin polarized currents. In short, these graphene systems are typical candidates for electrical spintronic devices as spin filtering. [ABSTRACT FROM AUTHOR]

The magnetic, electric and optical properties of BiFe 0.875 Cr 0.125 O 3 (BFCO) doped with aliovalent ions (Na + , Mg 2+ ) and isovalent ion (Al 3+ ) are investigated by the first principle spin-polarized density functional theory calculations. It is demonstrated that the substitution of M (M = Na + , Mg 2+ , Al 3+ ) for Fe can produce net magnetic moments of 3.0, 2.0 and 3.0 μB, respectively. Besides, Na + doped BFCO exhibits metallicity while Mg 2+ doped system behaves as half-metallicity. Systematic study of electronic structures show that this conversion from semiconductor (BFCO) to half-metal or metal is mainly attributed to the shifting of O 2p, Bi 6s, and Cr 3d states induced by doping with aliovalent Na + or Mg 2+ . Furthermore, the aliovalent ions doped samples express high static dielectric constants of 12.08, 29.44, large refractive indexs of 5.41, 3.46 and both their absorption edges near zero, suggesting advanced optical response in visible region of the doped samples. [ABSTRACT FROM AUTHOR]

Electron tunneling through a single magnetic barrier in a HgTe topological insulator has been theoretically investigated. We find that the perpendicular magnetic field would not lead to spin-flip of the edge states due to the conservation of the angular moment. By tuning the magnetic field and the Fermi energy, the edge channels can be transited from switch-on states to switch-off states and the current from unpolarized states can be filtered to fully spin polarized states. These features offer us an efficient way to control charge/spin transport in a HgTe/CdTe quantum well, and pave a way to construct the nanoelectronic devices utilizing the topological edge states. [ABSTRACT FROM AUTHOR]

Using first-principles calculations, we have systematically investigated the structural, electronic and magnetic properties of blue phosphorene doped by group IV and VI atoms, including C, Si, Ge, Sn, O, S, Se and Te. All the doped systems are energetically stable. Only C, Si, Ge and O-substituted systems show the characteristics of spin polarization and the magnetic moments are all 1.0 μ B . Moreover, we found that C, Si, Ge and O doped systems are indirect bandgap semiconductors, while Sn, S, Se and Te doped systems present metallic property. These results show that blue phosphorene can be used prospectively in optoelectronic and spintronic devices. [ABSTRACT FROM AUTHOR]

First-principles calculations, were carried out to study the structural stability of the cubic [ (F m 3 ‾ m) , (F 4 ‾ 3 m) ] and tetragonal [ (I 4 / m m m) , (I 4 ‾ m 2) ] phases, of R u 2 V Z (S i ; G e) full Heusler compounds; where Energy of formation, elastic, Mechanical, phonon and thermodynamic properties and electronic density of states were determined. Through our results, all ferromagnetic phases exhibit a total magnetic moment of 1 μ B for both R u 2 V S i and R u 2 V G e compounds, except the tetragonal (I 4 ‾ m 2) phase that manifest a zero ( 0 μ B) total magnetic moment.Further, the antiferromagnetic state of the cubic phase F m 3 ‾ m R u 2 V Z (S i ; G e) was found energetically more favorable than the ferromagnetic one.The analysis of the calculated elastic and dynamic properties, revealed that only the regular cubic phase (F m 3 ‾ m) of the R u 2 V S i and the regular tetragonal phase (I 4 / m m m) of the R u 2 V G e are the most stable among the considered phases. The calculated electronic density of states for the ferromagnetic stable phases, confirm the existence of a half-metal character with high spin polarization (P n) of: ∼ 91 % and ∼ 100 % for the R u 2 V S i and R u 2 V G e respectively. • In This article applied the Full full-potential linearized augmented-plane-wave method (FP-LAPW) to the determination of the structural, dynamic mechanical and electronic properties of the two full Heusler compounds R u 2 V S i and R u 2 V G e. • The antiferromagnetic state for the cubic (F m 3 ‾ m) R u 2 V Z (S i ; G e) compounds was found more favorable than the ferromagnetic one. • The analysis of the calculated elastic and dynamic properties, show that only the regular cubic phase (F m 3 ‾ m)) of the R u 2 V S i and the regular tetragonal phase (I 4 / m m m) of the R u 2 V G e are the most stable among the considered phases. • The electronic density of states for the ferromagnetic stable phases, confirm the half-metal character with high spin polarization for the R u 2 V S i and R u 2 V G e respectively. [ABSTRACT FROM AUTHOR]

Opening a bandgap in graphene is probably one of the most important and urgent topics in the graphene research currently, since most of the proposed applications for graphene in nanoelectronic devices require the ability to adjust its bandgap. In this work we perform first-principles calculations to investigate the alterations at the structural, energetic, electronic and magnetic properties of hybrid graphene-BC 2 N monolayers (GBMLs) and zigzag graphene-BC 2 N nanoribbons (ZGBNRs) with different types of extended line defects (ELDs) at the grain boundary. Different reconstruction processes are observed forming different types of ELDs depending on the nature of the atoms into the grain boundary as well as the structures type, arrangement, position/size of domains, and inserted atoms. The inclusion of these ELDs creates edge type effects in the ELD at GBNMLs, inducing spin polarization and localization of states at the Fermi level. GBNMLs show a wide range of electronic structures going from semimetallic to semiconducting and metallic, which can have magnetic ground states with ferromagnetic and antiferromagnetic. ZGBNRs are always metallic with ferromagnetic coupling between carbon atoms at the structures edges. [ABSTRACT FROM AUTHOR]

Recently, insulator-metal transition was found experimentally in Gd-doped SrTiO 3 films. Here, we present first-principle investigation on the structural, electronic and magnetic properties of Sr 1−x Gd x TiO 3 within density-function theory. The spin-polarized calculations give a diamagnetic insulator at x=0, a ferrimagnetic metal 0.125≤ x≤0.5 and a ferrimagnetic insulator x=1 and all Ti ions moments are antiparallel to Gd ions moments. Magnetic Gd-doping distorts the structures of Sr 1−x Gd x TiO 3 films and results in ferrimagnetism. Doped electrons occupy the bottom of conduction bands so that insulator-metal transition occurs. These calculated results are in agreement with available experiments. [ABSTRACT FROM AUTHOR]

Calculations based on density functional theory have been performed to investigate the potential of the rare earth free Fe 5 Ge 3 magnets for applications in spintronics. We evaluated properties intrinsically important for spintronics like spin polarization and magnetic anisotropy for the case of pure Fe 5 Ge 3 and for the case of natural dopant atoms such as Mn, Co and Ni. The results indicate that the pure system has a spin polarization of 28% at the Fermi level. An increase in the spin polarization can be obtained by incorporating Co, Ni and Mn atoms as dopants being the maximum value of 57% obtained by Co doping at type-I sites. A certain control of the magnetocrystalline anisotropy can be also obtained by doping, indicating that the Fe 5 Ge 3 system is suitable for spintronic applications. • Spin polarization and magnetic anisotropy were calculated for pure and doped Fe 5 Ge 3. • An increase in spin polarization at the Fermi level can be obtained by incorporating Co, Ni and Mn atoms as dopants. • Magnetocrystalline anisotropy can be shaped by doping the Fe 5 Ge 3. [ABSTRACT FROM AUTHOR]

The inverse spin Hall effect (ISHE) has been detected and separated from spin rectification effect (SRE) by inverting spin injection direction in metallic system. This work is based on the relation between the two effects and the spin injection direction: the sign of V ISHE changes because of the reversing direction of spin injection while the V SRE is independent on it. According to the different voltage signals before and after the spin injection inverted, the pure V ISHE and V SRE are calculated by utilizing the method of addition and subtraction. The signals can be separated in a wide range of frequency and power. [ABSTRACT FROM AUTHOR]

A series of full Heusler (FH) alloys Co 2 FeZ (Z = Al, Ga, Si, Ge, S, Se and Te) have been investigated using density functional theory (DFT) with full potential-linearized augmented plane wave (FPLAPW) method within generalized gradient approximation (GGA) and Perdew-Burke-Ernzerhof (PBE) functional. Most stable structures are determined by considering four different atomic arrangements i.e. L2 1 -I/II (conventional) and XA-I/II (inverse) configurations. Stable magnetic phases like anti-ferromagnetic (AFM), nonmagnetic (NM) and ferromagnetic (FM) are evaluated and results revealed that FM phase is the most stable of all alloys. Spin band structures are calculated by applying GGA and GGA + mBJ approach. The results showed the half metallic nature of Co 2 FeAl and Co 2 FeGe alloys. The obtained band diagrams are compared with density of states (DOS) and revealed that the both Fe and Co atoms contributes maximum in total magnetic moment (MM). The calculated values of total magnetic moment (M T) of all compounds range from 4 to 6 μ B and are in well agreement with the findings of Slater-Pauling Rule (SPR). Both alloys i.e. Co 2 FeAl and Co 2 FeGe showed 100% level of spin polarization (SP) at Fermi level. Mean field approximation (MFA) is employed to determine Curie temperature (Tc) and the values thus obtained are higher than room temperature. Furthermore, the thermoelectric parameters i.e. Seebeck coefficient (S) along with thermal (κ) and electrical (σ) conductivities for both Co 2 FeAl and Co 2 FeGe alloys are calculated and discussed in detail. The obtained results envisaged that the investigated alloys are suitable candidates for thermoelectric and spintronic applications. • Structural stability using conventional and inverse atomic arrangements. • Determination of spin band diagrams using GGA and GGA + mBJ. • Half metallic behavior through spin polarization. • Calculations of Curie temperature and magnetic moment. • Study of thermoelectric parameters. [ABSTRACT FROM AUTHOR]

Coherent spin transport through bilayer graphene (BLG) nanoflakes sandwiched between two electrodes made of single-layer zigzag graphene nanoribbon was investigated by means of Landauer-Buttiker formalism. Application of a magnetic field only on BLG structure as a channel produces a perfect spin polarization in a large energy region. Moreover, the conductance could be strongly modulated by magnetization of the zigzag edge of AB-stacked BLG, and the junction, entirely made of carbon, produces a giant magnetoresistance (GMR) up to 100%. Intestinally, GMR and spin polarization could be tuned by varying BLG width and length. Generally, MR in a AB-stacked BLG strongly increases (decreases) with length (width). [ABSTRACT FROM AUTHOR]

New rare-earth half-metallic ferromagnets X 0.75 Eu 0.25 O ( X =Ca, Sr and Ba) with the NaCl structure are predicted based on the first-principles calculations. These materials only have up-spin subbands at the Fermi level and their net magnetic moments are all 7.00 µ B per unit cell, which exhibits the evident half-metallic characteristics. Their energy gaps and half-metallic gaps are both wide so that they all have high Curie temperatures and stable half-metallicity, holding great potential applications in spintronics. From the calculated formation energies, it is possible to prepare Sr 0.75 Eu 0.25 O and Ba 0.75 Eu 0.25 O experimentally. However, it may be difficult to prepare Ca 0.75 Eu 0.25 O in experiments. The magnetic moments and the half-metallicity of X 0.75 Eu 0.25 O mainly originate from the spin-polarization of Eu 4f-orbitals, which are caused by the strong octahedral crystal field in the ligand compound ML 6 consisting of the Eu-ion and six O-ions around it. [ABSTRACT FROM AUTHOR]

We study spin-dependent electron transport properties of zigzag silicene nanoribbons in the presence of anti-ferromagnetic exchange field using a nonequilibrium Green׳s function method. Applying a transverse electric field, spin splitting can take place and the silicene nanoribbon can work as a spin filter. The spin polarization is calculated and it is shown that the spin filtering is perfect and the spin states of electrons are fully coherent. The spin direction of transmitted electrons through the silicene filter can be easily controlled by changing the transverse electric field direction. Using Hubbard model, we take into account the electron–electron interaction and we find that although this interaction causes some changes in the electron conductance, it has no destructive effect on spin filtering properties. The effect of a single vacancy on electron transport is also investigated and it is found that, the vacancy causes to decrease the electron conductance; however, the spin-dependent properties remain the same. The vacancy in the near of the edges of nanoribbon has less destructive effect on electron conductance than that in the middle. [ABSTRACT FROM AUTHOR]

The electronic, magnetic, and optical characteristics of the bulk and (111), (001) surfaces of the Sc 2 CoSn Heusler compound are calculated using first principle calculations. Investigating these properties is performed with FPLAPW, which takes into account the approximate function correlation within the Generalized Gradient Approximation (GGA). The results show that the bulk Sc 2 CoSn compound achieves a ferromagnetic half-metallic characteristic with an energy gap of 0.54 eV. The density of states for Sc(1)-, Sc(2)-, Co-terminations at the (111) surface, and the Sc(1)Co- and Sc(2)Sn-terminations at the (001) surface show metallic properties at the spin up and spin down channels, whereas the Sn-termination at (111) surface has a half-metallic nature with full spin polarization. A matter that paves the way for many applications related to constructing a massive magnetic resistance. At all ends, the values of magnetic moments of (111) and (001) surfaces demonstrate that Co atoms contribute the most. The optical investigation of the compound shows high reflectivity in the infrared region of the photon energy. The optically non-metallic behavior of the Sc 2 CoSn compound was revealed by the imaginary component of the dielectric function, with an optical band gap of roughly 1 eV. Based on the obtained results, the investigated material could be utilized in many photo-electronics applications including photo-senses, photo-catalyst, and photo-electrochemical areas. • The electronic, magnetic, and optical characteristics of the bulk and (111), (001) surfaces of the Sc 2 CoSn Heusler compound are calculated. • The Sn-termination at (111) surface has a half-metallic nature with full spin polarization. • The optical investigation of the compound shows high reflectivity in the infrared region of the photon energy. • The investigated material could be utilized in many photo-electronics applications including photo-senses, photo-catalyst, and photo-electrochemical areas. [ABSTRACT FROM AUTHOR]

Based on density functional theory, the electronic structures and magnetic properties have been studied in MoS 2 monolayer via substitutional doping of nonmagnetic elements (IA, IIA, and IIIA elements). The magnetic moment of those doped systems origins form the interplay between the crystal-field of MoS 2 matrix and localized Mo 4d states. On the whole, these doped MoS 2 monolayers exhibit a half-metal→spin gapless (or narrow gap) semiconductor→ferromagnetic semiconductor transition as the dopants change from IA to IIIA groups. Electron and hole doping by a potential gate can realize a transition from ferromagnetic semiconductor to half metal. In important, the spin-polarization direction is switchable depending on the doped carrier’s type. [ABSTRACT FROM AUTHOR]

Absrtact Using density functional theory, we predict half-metallicity in edge hydrogenated armchair boron nitride nanoribbons (ABNNRs). The predicted spin polarization is analyzed in detail by calculating electronic and magnetic properties of these hydrogenated ABNNRs by means of first-principles calculations within the local spin-density approximation (LSDA). ABNNRs with only edge B atoms passivated by H atoms are found to be half-metallic (regardless of their width) with a half-metal gap of 0.26 eV. Upto 100% spin polarized charge transport is predicted across the Fermi level owing to the giant spin splitting. Transmission spectrum analysis also confirms the separation of spin up and spindown electronic channels. It is revealed that H-passivation of only edge N atoms transforms non-magnetic bare ribbons into energetically stable magnetic semiconductors whereas hydrogenation of both the edges does not affect the electronic and magnetic state of bare ribbons significantly. The results are promising towards the realization of inorganic spintronic devices. [ABSTRACT FROM AUTHOR]

Using the non-equilibrium Green’s function method combined with the density functional theory, we investigate the spin transport properties of carbon chains connected with armchair- and zigzag-edged graphene nanoribbon (ZGNR) electrodes at finite bias with the parallel magnetism configuration. When spin polarized electrons are injected into carbon chains from the ZGNR electrode, the β-spin current is nearly zero, while the α-spin current shows large values in the calculated bias region, thus the spin polarization 100% can be achieved, which is a promising pathway for developing a spin filter. [ABSTRACT FROM AUTHOR]

In this paper, the surface properties of the (001) surface in PrMnO 3 are investigated using the projector augmented plane wave (PAW) methods within the spin-polarization generalized gradient approximation (GGA+ U ), where U is on-site Coulomb interaction correction. The result of the total density of states shows a half-metallic ground state for PrMnO 3 in GGA+ U treatment. The optimized structure parameters of both cubic and orthorhombic bulk phases are obtained. The electronic properties of the cubic PrMnO 3 (001) surface with PrO- and MnO 2 -terminations are discussed. Based on the results of the calculated surface energies, we predict the surface energies of three low-index surfaces follows the sequence of (001)<(111)<(110). The rumpling for the PrO-terminated surface is much larger than that of the MnO 2 -terminated surface. Both the PrO- and MnO 2 -terminated surfaces display a reduction of d 12 interlayer distance and an expansion of d 23 . Bader effective charge of the ion is much smaller than its formal charge which is due to the partial Mn–O bond covalency. The oxygen-vacancy formation energy in bulk PrMnO 3 is found to be smaller than other perovskites, e.g. LaMnO 3 and SrTiO 3 . We find that the formation energy of oxygen-vacancy on MnO 2 -terminated surface is lower than the formation energy of oxygen-vacancy on PrO-terminated surface and Sr-doped PrMnO 3 makes oxygen-vacancy formation more easily compared pure PrMnO 3 . [ABSTRACT FROM AUTHOR]

Determining the atomic origin of magnetism in non-magnetic elements doped dilute magnetic semiconductors (DMS) is a key issue to understand the room temperature ferromagnetism. Here, using electron magnetic circular dichroism (EMCD), an element-selectivity and high spatial resolution technique, we provide unambiguous experimental evidence: spin polarization of carbon atoms contributes to the local magnetic moments of Al-doped 4H–SiC DMS. The result is further confirmed by first-principle calculations. [ABSTRACT FROM AUTHOR]

In the present study, the structural stability and electronic properties of boron nanostructures were analyzed using first-principles calculations. The main focus was concentrated in boron monolayers and nanotubes including substitutional carbon impurities. The obtained results indicate that all doped structures are more stable than the pristine ones. It was found that the doped planes have a metallic electronic behavior, similar to the undoped sheets. For boron nanotubes, pristine structures exhibit a semiconductor behavior for small diameters, in close agreement with previous studies. However, both types of doped tubes have a null gap, regardless of the diameter. It was also found, from calculations including spin polarization, a non-zero magnetization for tubes with a specific condition of doping. [Display omitted] • Boron layer doped with a carbon substitutional impurity increases the structural stability. • Carbon doping does not induce significant modifications in the density of states. • Carbon substitutional atom located in a particular position induces a net spin polarization. [ABSTRACT FROM AUTHOR]

We present a theoretically investigation about the electron transport through a single-barrier structures in HgTe/CdTe quantum wells (QWs) with inverted band structure. For HgTe/CdTe QWs structure, the transmission probabilities show great dependence on the Rashba spin–orbit interaction (RSOI), the incident angle, the incident Fermi energy and the electric modulation potential. By tuning the modulation amplitude with gate voltage or the strength of RSOI modulation, the efficient spin-polarized P Z = 1 is achieved, which is formed due to the spin-split in band spectrum induced by the RSOI modulation. This electric mechanism provides us a way to manipulate the spin polarization electrically and convenient for experimental verification. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials with intrinsic ferromagnetism, a sizable magnetic anisotropy energy (MAE) and large spin polarization are desirable for realizing the practical spintronic applications. Base on first-principles calculations, the stability, electronic and magnetic properties of monolayer CrOBr are systematically investigated. Monolayer CrOBr is ferromagnetic semiconductor with a band gap of 1.547 eV, it possesses in-plane magnetic anisotropy with a value of −0.017 meV/formula unit (f.u.). The band gap of monolayer CrOBr can be regulated in the range of 1.547-1.145 eV by applying biaxial tensile strain. Monolayer CrOBr changes from FM state to AFM state when tensile strain increases to 8%. The MAE of monolayer CrOBr reaches a large value of −0.057 meV/f.u. at tensile strain of 8%, which is enhanced by 235% compared to that of unstrained system. The tunable MAE and electronic structure indicate that monolayer CrOBr may be a promising candidate in spintronic devices. • Monolayer CrOBr is FM semiconductor with in-plane magnetic anisotropy of −0.017 meV/formula unit. • The MAE can be enhanced by 235% when biaxial tensile strain reaches 8%. • The band gap varies in the range of 1.547-1.145 eV by applying biaxial tensile strain. [ABSTRACT FROM AUTHOR]

We study the quantum capacitance and the Landau levels (LLs) in n-type monolayer InSe subjected to a vertical magnetic field. Starting from a single band k ⋅ p Hamiltonian, we analytically obtain the LLs by solving the Hamiltonian and find that the LLs have a uniform distribution on the LL index and magnetic field, i.e., the equal LL spacings. Further, the LLs are fully spin polarized under moderate magnetic fields originating from the spin–orbit coupling and Zeeman splitting. The magneto-capacitance peaks show one-to-one correspondence to the LLs, resulting in a perfect square-wave-shaped spin polarization. Our results is useful to detect the effective mass and spin–orbit coupling parameters of n-type monolayer InSe and design spintronics devices based on it. • We analytically obtain the Landau levels and magneto-capacitance of n-type monolayer InSe. • The Landau levels are spin-polarized due to the spin orbit coupling and Zeeman splitting, resulting fully spin-polarized magneto-capacitance. • The magneto-capacitance spectrum is useful to determine the band parameters and design spintronic devices. [ABSTRACT FROM AUTHOR]

We present a theoretically investigation about the electron transport through a single-barrier structures in HgTe/CdTe quantum wells (QWs) with inverted band structure. For HgTe/CdTe QWs structure, the transmission probabilities show great dependence on the Rashba spin–orbit interaction (RSOI), the incident angle, the incident Fermi energy and the electric modulation potential. By tuning the modulation amplitude with gate voltage or the strength of RSOI modulation, the efficient spin-polarized P Z = 1 is achieved, which is formed due to the spin-split in band spectrum induced by the RSOI modulation. This electric mechanism provides us a way to manipulate the spin polarization electrically and convenient for experimental verification. [ABSTRACT FROM AUTHOR]

In the present study, the structural stability and electronic properties of boron nanostructures were analyzed using first-principles calculations. The main focus was concentrated in boron monolayers and nanotubes including substitutional carbon impurities. The obtained results indicate that all doped structures are more stable than the pristine ones. It was found that the doped planes have a metallic electronic behavior, similar to the undoped sheets. For boron nanotubes, pristine structures exhibit a semiconductor behavior for small diameters, in close agreement with previous studies. However, both types of doped tubes have a null gap, regardless of the diameter. It was also found, from calculations including spin polarization, a non-zero magnetization for tubes with a specific condition of doping. [Display omitted] • Boron layer doped with a carbon substitutional impurity increases the structural stability. • Carbon doping does not induce significant modifications in the density of states. • Carbon substitutional atom located in a particular position induces a net spin polarization. [ABSTRACT FROM AUTHOR]

We study the quantum capacitance and the Landau levels (LLs) in n-type monolayer InSe subjected to a vertical magnetic field. Starting from a single band k ⋅ p Hamiltonian, we analytically obtain the LLs by solving the Hamiltonian and find that the LLs have a uniform distribution on the LL index and magnetic field, i.e., the equal LL spacings. Further, the LLs are fully spin polarized under moderate magnetic fields originating from the spin–orbit coupling and Zeeman splitting. The magneto-capacitance peaks show one-to-one correspondence to the LLs, resulting in a perfect square-wave-shaped spin polarization. Our results is useful to detect the effective mass and spin–orbit coupling parameters of n-type monolayer InSe and design spintronics devices based on it. • We analytically obtain the Landau levels and magneto-capacitance of n-type monolayer InSe. • The Landau levels are spin-polarized due to the spin orbit coupling and Zeeman splitting, resulting fully spin-polarized magneto-capacitance. • The magneto-capacitance spectrum is useful to determine the band parameters and design spintronic devices. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials with intrinsic ferromagnetism, a sizable magnetic anisotropy energy (MAE) and large spin polarization are desirable for realizing the practical spintronic applications. Base on first-principles calculations, the stability, electronic and magnetic properties of monolayer CrOBr are systematically investigated. Monolayer CrOBr is ferromagnetic semiconductor with a band gap of 1.547 eV, it possesses in-plane magnetic anisotropy with a value of −0.017 meV/formula unit (f.u.). The band gap of monolayer CrOBr can be regulated in the range of 1.547-1.145 eV by applying biaxial tensile strain. Monolayer CrOBr changes from FM state to AFM state when tensile strain increases to 8%. The MAE of monolayer CrOBr reaches a large value of −0.057 meV/f.u. at tensile strain of 8%, which is enhanced by 235% compared to that of unstrained system. The tunable MAE and electronic structure indicate that monolayer CrOBr may be a promising candidate in spintronic devices. • Monolayer CrOBr is FM semiconductor with in-plane magnetic anisotropy of −0.017 meV/formula unit. • The MAE can be enhanced by 235% when biaxial tensile strain reaches 8%. • The band gap varies in the range of 1.547-1.145 eV by applying biaxial tensile strain. [ABSTRACT FROM AUTHOR]

The structural, electronic, magnetic, elastic and thermoelectric properties of full-Heusler alloys Co 2 ZrZ (Z = Al, Si, Ga and Sn) are investigated using the augmented plane wave method (FP-LAPW) based on the framework of spin density functional theory. The term of the exchange and correlation potential (XC), is treated by the generalized gradient approximation GGA and Trans-Blaha-modified Becke–Johnson (TB-mBJ). The results obtained showed that the Cu 2 MnAl-type structure has more stable energy than the Hg 2 CuTi-type structure for all the full-Heusler studied. From electronic calculations, it is found that all the compounds studied have an indirect band gap with a half-metallic behavior. Furthermore, we also found that all materials have integral magnetic moments which are mainly due to 100% spin polarization at Fermi energy. The calculated elastic constants and the anisotropy shear factors indicate that these compounds have a ductile character and are mechanically stable. Finally, we calculated the thermoelectric properties by applying Boltzmann theory as implemented in the BoltzTraP code. The results obtained for the merit factor (ZT) and Seebeck coefficient (S) make these materials promising candidates in thermoelectric applications and in spintronics devices. • Investigation of optoelectronic and thermoelectric properties for CO 2 ZrZ (Z = Al, Si, Ga and Sn) using Wien2k code. • Heusler alloys with indirect band gap and a half-metallic behavior. • The studied compounds have a ductile character and stable mechanically. • High electrical conductivity and a figure of merit which is close to unity at low temperatures. • They can be considered as a source of low-temperature energy to produce electricity. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) calculations have been made on cubic perovskite compound, SrMnO 3 to investigate electronic, magnetic, optical and thermodynamic properties. The transport properties have also been calculated with BoltzTrap code. The analysis of both density of state (DOS) and band structures show the half metallic behaviour of the compound having a band gap for spin down state only, which suggests its potential applications in spintronic devices. DOS profile shows that the major contribution has been received from Mn-3d and O-2p orbitals near Fermi level. Mn-3d orbitals are responsible for the ferromagnetic behavior and total magnetic moment of the compound. Thermoelectronic and optical conductivity predict the metallic nature for the compound. The figure of merit (zT parameter) found to be ~0.97 at 300 K, predicts as a potential candidate to be used as thermoelectric material for energy devices. Optical responses show a maximum absorption between the low energy range of ~2.0–4.0 eV (visible and UV). Therefore, it could be utilized for its applications in different optical devices for visible and ultraviolet light. • The analysis of both density of state (DOS) and band structures show the half metallic behaviour of the compound. • Thermoelectronic and optical conductivity predict the metallic nature for the compound. • Optical responses show a maximum absorption between the low energy range of ~2.0–4.0 eV (visible and UV). • Therefore, it could be utilized for its applications in different optical devices for visible and ultraviolet light. [ABSTRACT FROM AUTHOR]

We study the dynamical spin susceptibilities of biased bilayer graphene due to spin polarization effects in the context of tight binding model Hamiltonian. Green's function approach has been implemented to find the behavior of dynamical spin susceptibility of bilayer graphene within linear response theory. We have found the frequency dependence of imaginary part of spin susceptibilities for different values of bias voltage. Also the dependence of both transverse and longitudinal spin susceptibilities on spin polarization has been investigated in details. The frequency position of sharp peaks in the frequency dependence of the susceptibilities introduce the collective magnetic excitation modes of itinerant electrons on bilayer system. • The study of imaginary parts of spin susceptibilities of bilayer graphene in the presence of magnetic ordering. • The investigation of bias voltage on the susceptibilities of bilayer graphene. • The study of the effect of stacking type on the behavior of frequency dependence of susceptibilities. [ABSTRACT FROM AUTHOR]

The crystal, electronic, magnetic and optical properties of the Sr 2 CaOsO 6 double perovskite compounds have been investigated in this work, using density functional theory as implemented in the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method, employing the Generalized Gradient Approximation (GGA-PBE), GGA + U (Hubbard Coulomb correction) and GGA plus Trans-Blaha-modified Becke–Johnson (TB-mBJ-GGA) as the exchange correlation. According to the structural results, the lattice parameter is in agreed well with the previous experimental data. Spin polarization calculations has shown half-metallic behavior with ferrimagnetic ground state coupling for Ca and Os spins for Sr 2 CaOsO 6 compound. Our calculated electronics results within the TB-mBJ-GGA show that our studied material has direct half-metalic (HM) gaps energy in (Γ v -Γ C) directions with a value equal 2.08 eV and net magnetic moment of 2.000μ B. The most contribution of total magnetic moment is by Osmium atom. For optical properties, it can be concluded that Sr 2 CaOsO 6 material has a high absorption and can be used in future Spintronics and Optoelectronic applications in a large energy range of the light spectrum which extends from visible to ultraviolet. • We consider Sr 2 CaOsO 6 double perovskites compound. • The crystal, electronic, magnetic and optical properties have been investigated. • GGA-PBE, GGA + U and TB-mBJ-GGA approximations have been employed. • Our studied material shows half-metallic behavior with ferrimagnetic ground state. [ABSTRACT FROM AUTHOR]

Spin polarization, when induced in a non-ferromagnetic material, can change the underlying material behavior especially if the spin diffusion length is of the same order as the sample dimension such as thickness. In this study, we experimentally demonstrate thermal hysteretic behavior induced by spin polarization in Ni 80 Fe 20 (10 nm)/Au (100 nm) bilayer freestanding sample. The thermal hysteresis behavior is uncovered using magneto thermal characterization based on self-heating 3ω method. The third harmonic voltage shows diverging behavior and thermal hysteresis during cooling and heating of the sample under an applied magnetic field, which is attributed to the spin accumulation. The spin accumulation and thermal hysteresis in Au occurs due to ferromagnetic proximity polarization from Ni 80 Fe 20 layer. The observed hysteresis behavior is also attributed to freestanding thin film structure and absence of substrate effects leading to longer spin diffusion length. This study demonstrates experimental evidence of ferromagnetic proximity polarization and resulting changes in thermal transport behavior in Au thin films. • We measured magneto-thermal transport in Ni 80 Fe 20 /Au bilayer freestanding thin films. • The temperature dependent measurement shows thermal hysteresis. • The hysteretic behavior is attributed to the ferromagnetic proximity polarization. [ABSTRACT FROM AUTHOR]

The electronic structure and spin properties of Titanium (Ti) or Iron (Fe) doped hexagonal boron nitride (h -BN) nanosheet have been studied by using ab initio study based on density functional theory (DFT). GGA + U calculations show that one Ti or Fe atom can introduce local magnetic states into the system. Impurity levels will be generated in band gap, and this will lead to spin polarization. The calculated magnetic moments are 1.0 μ B and 2.9 μ B for Ti and Fe, respectively. Furthermore, the magnetic moments are all contributed by the d orbitals of doped atoms in h -BN monolayer. The studies of magnetic coupling reveal that two Ti atoms are mainly coupled antiferromagnetically at different distances between Ti atoms in h -BN monolayer. The Ti-doped system is coupled ferromagnetically only when Ti–Ti distance is 6.625 Å. While the magnetic coupling exhibits regular oscillation characteristics in the system with two Fe atoms doping at different distances. This novel property in Fe-doped h -BN nanosheet provides a new way to control the spin property of material. Our research is beneficial to the development of spintronics. • Magnetism in Ti or Fe-doped h -BN system has been studied by GGA + U method. • We show in theory that impurity Ti can't lead to macromagnetism in BN monolayer. • The magnetic coupling between Fe atoms at different distances will produce regular oscillation. • The novel property in Fe-doped h -BN nanosheet provides a new way to control the spin property of material. [ABSTRACT FROM AUTHOR]

The electronic structures and magnetic properties of sulphur vacancies and manganese(Mn)-doped monolayer molybdenum disulfide were calculated by first-principles. The results show that only the sulphur vacancies do not produce magnetism in the system, while the Mn-doped monolayer MoS 2 has a high magnetic moment of 2.0 μ B , which is due to the hybridization of Mn:3 d , Mo:4 d and S:3 p orbitals. On this basis, the different configurations of the two Mn atom positions in the two Mn atoms doping systems are considered, and the most stable geometric structure of the two Mn atoms doping systems is determined. It is found that the total magnetic moments of two Mn atoms doped monolayer MoS 2 is 4.3 μ B. Then the isolated magnetic moments of two Mn atoms in the doped system are investigated, which are both 1.19 μ B , respectively. And the Mn:3 d -Mo:4 d -Mo:4 d -Mn:3 d coupling chain may be the reason why the 2Mn-doped MoS 2 has the spin polarization phenomenon. It is intriguing that the magnetic moments are raised in the two Mn doped monolayer MoS 2 system. Our research confirms the potential application of a novel dilute magnetic semiconductor (DMS) based on Mn-doped single-layer MoS 2. • We perform a first-principles density-functional theory (DFT) to investigate the electronic and magnetic properties of (V S , Mn) co-doped MoS 2. • The Mn doped MoS 2 system maintains semiconducting properties, and the magnetic moment of the Mn doped MoS 2 system is highly improved.. • 2Mn doped MoS 2 system induces magnetic ground states with the magnetic moment of 4.3 μ B. [ABSTRACT FROM AUTHOR]

The geometrical and magnetic properties of C atoms doped graphene-like ZnO (g-ZnO) monolayer supercell with the concentrations of 6.25%, 12.5% 18.75% and 25% has been calculated using the first-principles method. The calculated results indicate that C doped g-ZnO monolayer causes the structural distortion. G-ZnO monolayer with one O atom substituted by one C atom is ferromagnetic (FM) half-metal. When the doped concentration of C is 12.5% 18.75% and 25%, the models present strong FM metal properties. The hybridization between C atoms and neighboring host atoms results in the spin polarization between C(2p)-Zn(4d)-O(2p), which causes strong FM properties. • C atoms replacing one or more O atoms causes the structural distortion. • Doped g-ZnO monolayer with one or more C atoms exhibits strong magnetism. • The hybridization between C atoms and neighboring host atoms results in the spin polarization between C(2p)-Zn(4d)-O(2p). [ABSTRACT FROM AUTHOR]

The thermodynamic stability and half-metallic ferromagnetism of alkali-based beryllium perovskites XBeO 3 (X = Li, Na, K, Rb, and Cs) in cubic phase have been analyzed by the first-principles approach. Our results show that more energy is released in the ferromagnetic (FM) phase than the antiferromagnetic (AFM) phase during optimization, revealing the FM phase more stable than the AFM state. Moreover, the thermodynamic, structural and mechanical stabilities in FM state has been confirmed by the enthalpy of formation, tolerance factor, and Born stability criteria for cubic structured perovskites. The Heisenberg classical model has been used to predict the Curie temperature and spin polarization. The hole mediated double-exchange mechanism illustrates spin-coupling based half-metallic ferromagnetism that leads to XBeO 3 as potential materials for spintronic device fabrication. The strong hybridization between the atomic states of 16-atom supercell, especially, the p-p coupling of p -X and p -O yields the total magnetic moment 3μ B /unit cell. • Investigations of thermodynamic stability of alkali-based beryllium perovskites XBeO 3 (X = Li, Na, K, Rb, and Cs). • Investigations of origin of half-metallic ferromagnetism. • Investigations of electronic properties and spin polarized density of states. [ABSTRACT FROM AUTHOR]