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A high degree of spin polarization in half-metallic double perovskites is a prerequisite for several applications in spintronics, which depends crucially on the cationic order of the systems. This paper reports a study on tailoring the structure and morphology of nano-sized Sr 2 Fe 1- x Zn x MoO 6 (x = 0.05, 0.1, 0.15) materials to improve their spin polarization. The combined analysis of synchrotron X-ray diffraction and magnetization data shows that Zn replaces Fe in the B sites. Although the majority of particles have lateral dimensions in the range 30–60 nm as observed by scanning electron microscope, the samples with x = 0.1 and 0.15 show finite-size effects with superparamagnetism below room temperature and a reduced Curie temperature (from 410 K for x = 0.05–390 K for x = 0.15). The results are due to the formation of networks of insulating Mo–O–Zn–O–Mo linkages and anti-phase boundaries, which divide the particles into smaller domains with a mean diameter of ∼11 nm as determined via a Langevin fit. The almost perfectly ordered structure in the nanodomains is responsible for a high magnetoresistance ratio. A value of -42% at 5 K in 50 kOe is recorded for the sample x = 0.15. Via fitting the magnetoresistance curve using the Inoue-Mekagawa theory, the spin polarization of 99% is determined. [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]

• Highly ordered L2 1 type heusler alloy film on cu substrate. • Near stoichiometric Co 2 FeSn films by electrodeposition. • High magnetic moment, high T C and high effective anisotropy films. • Co 2 FeSn films (320 nm −1400 nm thick) with high crystalline order. • Minority band gap close (∼0.05 eV) to fermi level. Co 2 FeSn films have been electrochemically deposited on polycrystalline Cu substrates in potentiostatic mode. Processed films with thicknesses of 320 nm, 780 nm, and 1400 nm exhibited highly ordered L2 1 type crystal structure with saturation magnetizations of 1023.38 kA/m (5.08 ± 0.04 μ B /f.u.), 1035.31 kA/m (5.14 ± 0.04 μ B /f.u.) and 1044.34 kA/m (5.18 ± 0.04 μ B /f.u.) at 5 K and 965.00 kA/m (4.79 ± 0.04 μ B /f.u.), 967.75 kA/m (4.81 ± 0.04 μ B /f.u.), and 1003.52 kA/m (4.97 ± 0.04 μ B /f.u.) at 300 K, respectively. The soft ferromagnetic films possess coercivity of ∼ 15.92 kA/m (200 Oe) with a high effective anisotropy constant of ∼ 105 J/m3. Thermo-magnetization measurements yielded high Curie temperatures of 995 K, 1005 K, and 1123 K for films of thicknesses 320 nm, 780 nm, and 1400 nm, respectively. Tailoring the thickness from 320 to 1400 nm could be achieved by merely varying the electrodeposition time without appreciable departure from chemical stoichiometry or compromise in crystalline order or magnetic properties. This establishes a methodology to prepare high quality L2 1 ordered Co 2 FeSn films with a few hundred nanometers thickness by electrodeposition. Electrodeposited Co 2 FeSn films with high magnetic moment, high K e f f value, and high Curie temperature are potential candidates for fabricating nanomagnetic devices. [ABSTRACT FROM AUTHOR]

The photon-assisted electron transport properties through a parallel-coupled tri-quantum-dot system are studied using the time-dependent non-equilibrium Green's function theory. When a time-dependent external field irradiates a parallel-coupled three-quantum-dot system, the interaction between photons and electrons provides more novel transport characteristics. The average current can be switched between zero and non-zero by controlling the level of the time-dependent external field, indicating that an optically-controlled quantum switch can be realized. The time-dependent external field makes it more advantageous for the system to be designed as a magnetic-controlled quantum switch. If the magnetic flux and Rashba spin orbit coupling interaction are simultaneously considered, the average current exhibits a spin polarization phenomenon. For the spin down current, the bound states are formed as the magnetic flux takes an appropriate value, which greatly enhances the spin polarization. These research results are expected to contribute to the design of future quantum function devices. [ABSTRACT FROM AUTHOR]

• First-principles calculations performed for XA and L2 1 phases across X 2 FeAl series. • The degree of d-d orbital hybridization drives magnetic and electronic properties. • Increasing X-site valence electron counts result in increased hybridization levels. • Orbital hybridization trends must be considered when predicting material properties. First-principles calculations are performed for full (L2 1) and inverse (XA) Heusler compounds X 2 FeAl, where X comprise a range of 3d (Sc, Ti, V, Cr), 4d (Y, Zr, Nb, Mo), and 5d (Hf, Ta, W) early and middle column transition metal elements. The formation energy difference between full and inverse phase and the degree of d-d orbital hybridization with increasing total valence electron count are shown to drive the magnetic properties (total and atomic magnetic moments, spin polarization) and electronic properties (band structure and projected density of states) of the material system. Specifically, X-site atomic magnetic moments take on increasingly Fe character with increasing valence electron count, in both full and inverse Heusler phases. This can be explained by changes on the degree of d-d hybridization between X- and Fe-site d orbitals. Synchronized energy shifts in the PDOS of the X- and Y-sites (Fe) across each of the full and inverse Heusler series provide us insight to controlling spin polarization via composition. This work demonstrates the need to holistically study the thermodynamic phase stability, magnetic moments, and spin polarization of Heusler alloys, in the framework of anti-site disorder and in a wider compositional context. The end goal of this study is to benefit the mapping of experimental results in search of a specific property, by providing a methodology for extrapolating properties based on experimental or theoretical results. [ABSTRACT FROM AUTHOR]

In this paper, the charge and spin magneto coefficients of a double quantum dots system coupled in series connected to ferromagnetic electrodes with collinear magnetic alignments at finite bias voltage are theoretically investigated based on Green's functions in a linear response regime. Magneto and spin magneto thermopower are estimated as a function of the thermal gradient and quantum dot energy levels. Magneto conductance and spin magneto conductance are also studied. The results showed that the positions of the peaks can be controlled for each value of polarization, and the magneto conductance is negative where the charge conductance for parallel alignment is lesser than that for antiparallel alignment except in the case of high spin polarization and ferromagnetic spin exchange. Enhancing the magneto thermoelectric coefficients of double quantum dots is a promising step in creating adaptable magnetic switching for thermoelectric generations, which could find use in thermal energy-based logic circuits or heat control applications. [ABSTRACT FROM AUTHOR]

The carrier spin polarization of magnetic materials is one of the most critical elements for current-driven spintronics devices. Experimental evidence of spin polarization of magnetic oxides is still a matter of considerable debate although room-temperature ferromagnetism was reported in nearly all doped/undoped oxides materials. In this work, we systematically study the carrier spin polarization and non-uniform magnetization scattering of Zn 1−x Fe x Al 0.01 O (x = 0.05, 0.10) thin films in metallic regime. Spin polarization 65 ± 8% is confirmed experimentally for Zn 0.95 Fe 0.05 Al 0.01 O by Andreev Reflection spectroscopy, which reduces to 40 ± 5% for Zn 0.90 Fe 0.10 Al 0.01 O as Fe doping level increases to 10%. Magnetoresistance and Anomalous Hall effect are observed in Zn 1−x Fe x Al 0.01 O films which corroborates the spin-polarized carrier in spin-split bands close to the Fermi level. Furthermore, combining element mapping and Andreev reflection spectra, our results support that non-uniform magnetization of Zn 1−x Fe x Al 0.01 O films which introduces large inelastic spin-flip scattering at the interface of Zn 1−x Fe x Al 0.01 O/Pb superconducting junctions, and consequently reduction of spin polarization. The spin-polarized carrier and transport behaviors in Zn 1−x Fe x Al 0.01 O magnetic oxides provide the reliable evidence to identify the intrinsic ferromagnetism and an excellent platform for spintronics device applications. [Display omitted] • Spin polarization of carrier 65 ± 8% was determined quantitatively in Zn 0.95 Fe 0.05 Al 0.01 O thin film for the first time. • Carrier spin polarization and transport offer a reliable evidence to identify intrinsic ferromagnetism of doped oxides. • Element mapping and Andreev reflection spectra, confirm non-uniform magnetization distribution in Zn 0.90 Fe 0.10 Al 0.01 O film. • Ferromagnetism and Anomalous Hall effect of Zn 1−x Fe x Al 0.01 O films corroborate spin-split bands close to the Fermi level. [ABSTRACT FROM AUTHOR]

Spin-Polarized optical parameters for Sr 2 UFeO 6 double perovskite. [Display omitted] • The Sr 2 UFeO 6 is half-metallic having indirect energy band gaps. • The Sr 2 UFeO 6 to be anti-ferromagnetic with a major contribution from Fe+3. • The Sr 2 UNiO 6 , as ferromagnetic in nature with a major contribution from Ni+6. • The peaks in ε 2 ω are linked to various inter-band transitions. • These double perovskites show substantial absorption in UV region. The electronic, and magneto-optical properties of Sr 2 UXO 6 (X = Fe, & Ni) double perovskite materials, in the monoclinic structure, were calculated employing the full-potential Linearized augmented plane wave (FP-LAPW) approach based on the density functional theory (DFT). The results reveal that Sr 2 UFeO 6 is half-metallic and anti-ferromagnetic, whereas Sr 2 UNiO 6 is semiconducting and ferromagnetic. The spin-polarized linear optical features, including the dielectric functions, absorption coefficients, energy loss functions, reflectivity coefficient, and refractive indexes, have been calculated and analyzed in the energy range of 0–14 eV. The study reveals that both materials exhibit transmission at low energies, making them promising candidates for optoelectronic applications. Moreover, the presence of distinct absorption and reflectivity peaks suggests potential applications in tunable optical devices and sensors. The dispersion characteristics of the refractive index open up new possibilities for developing novel photonic materials. [ABSTRACT FROM AUTHOR]

The spin polarization of current plays an important role in the performance of spintronic devices. Therefore, a highly spin-polarized current source has always been explored through various methods. We study the effects of magnetic order on the electronic structures of antiferromagnetic (AFM) MnBi 2 Te 4 films. A significant spin splitting is found in the surface states of a AFM MnBi 2 Te 4 film with three septuple layers (SLs). The AFM film can show typical metallic behavior for spin-down electrons, and exhibit a semiconductor or insulator behavior with a band gap at the Fermi level for spin-up electrons, just like semimetal ferromagnets with theoretical spin polarization up to 100%. We also study that the electron transport in the 3-SLs AFM film with a square potential barrier, we find a highly spin-polarized current can be switched on and off by modulating the barrier height in the film. • 3-SLs AFM film exhibits a semimetal ferromagnets behavior. • A highly spin-polarized current can be switched on and off by modulating the barrier height. • Gapless surface states induced by magnetic order. • Large spin splitting in spin splitting. [ABSTRACT FROM AUTHOR]

The magnesium based spinel chalcogenides are outstanding materials for spintronic technology and energy applications. Herein, the modified Becke Johnson potential (TB-mBJ) was employed to investigate the electrical, ferromagnetism, and thermoelectric properties of MgDy 2 (S/Se) 4 spinels comprehensively. The energy emitted during optimization as well as formation energy has both been used to demonstrate the stability of the cubic phase. The density of states, Curie temperature, exchange coupling, and spin polarization are elaborated to address the nature of ferromagnetism. Further, half metallic ferromagnetism is studied in terms of hybridization, exchange energies, and exchange constants. In contrast to the clustering effect of the internal magnetic of Dy atoms in the structure, the lowering of Dy's magnetic moment and its transferring on Mg, and S/Se sites demonstrate that the ferromagnetism is caused by the exchange of electron spin. Furthermore, thermoelectric properties were studied and various thermoelectric parameters such as electrical and thermal conductivities, Seebeck coefficient (S), and power factor (PF) of the examined spinels have been determined. • Above room temperature ferromagnetism, and spintronic applications. • Quantum spin of electrons dominant the charge with multifuctional properties. • Exchange mechanism certifies the ferromagnetism by electron spin instead of magnetic ion clustering. • Half metallic ferromagnetism and 100 % spin polarization. • Large value of electrical conductivity and ultralow low values of thermal conductivity. [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]

• Different edge hydrogenations realize the transition of β -SiC 7 nanoribbons from semiconductors to half-metals to metals. • Spatially separated edge states lead to, arbitrary pairings of upper and lower edge hybridizations are able to diversify the bands near the Fermi level. • The heterojunction H H-zSiC 7 NR-2H H possesses good dual spin filtering properties at low bias and exhibits the NDR phenomenon. Atomic capping is a common approach in edge modification to tune band engineering and can be achieved experimentally through hydrogen plasma etching. Based on first-principles calculations, nine symmetric and asymmetric structures are constructed with different numbers of hydrogen atoms passivated at the edge of β -SiC 7 nanoribbons. An in-depth study reveals that different edge hydrogenations realize the transition from semiconductors to half-metals to metals, firstly, because different numbers of hydrogen atoms lead to different edge atomic orbital hybridizations, and, more importantly and specifically, because the bands around the Fermi level of β -SiC 7 nanoribbons are all derived from the spatially separated edge states, so that arbitrary pairings of upper and lower edge hybridizations are able to diversify the bands near the Fermi level and bring about a richer electronic properties. We also design the metallic H-zSiC 7 NR-H and semiconducting 2H-zSiC 7 NR-H into a heterojunction, which possesses good dual spin filtering properties at low bias, can achieve a spin polarization transition from -100 % to 100 %, and exhibits the NDR phenomenon. These findings suggest that β -SiC 7 nanoribbons have promising applications in the field of spintronics. [ABSTRACT FROM AUTHOR]

In this theoretical study, we investigate novel quaternary Heusler Fe–Rh–Mn–Al alloys in the X-type structure with different types of atomic ordering in the unit cell within the spin-polarized density functional calculations. The calculations showed that the 24 possible configurations converge to the 6 nonequivalent solutions. Two types of atomic ordering with the lowest total energy Fe(4c)Rh(4d)Al(4b)Mn(4a) and Mn(4c)Al(4d)Fe(4b)Rh(4a) are half-metallic ferrimagnets in which the spin polarization at the Fermi level is close to 100 %. However, no gap is open in the majority spin projection. The following values of the total magnetic moments for these alloys were obtained: 3.01 and 3.19 μ B /f.u., respectively. In the other types of atomic ordering, the half-metallic state is not formed. In FeAlRhMn, the magnetic moment on the manganese ion compensates for the moments on the other ions, and the total moment is close to zero. In the types (MnFeRhAl, AlRhFeMn) of atomic ordering with high energies, the metallic state is also realized, and the magnetic moments on the ions are ordered ferrimagnetically. In this work, we analyzed novel quaternary alloys with different types of atomic ordering motivated by the demand for alloys with a high spin polarization, among which the FeRhAlMn and MnAlFeRh alloys were found. Both with a half-metallic ferrimagnetic state and the lowest total energy among these alloys with the same chemical composition, which indicates the stability of the half-metallic state. The other types of atomic ordering are less energetically favorable, those alloys are ferrimagnetic metals with the low spin polarization. Taking into account the half-metallic state and high spin polarization, the quaternary FeRhAlMn and MnAlFeRh alloys have prospects for use in spintronic devices. [ABSTRACT FROM AUTHOR]

• The half metallicity of NiVTiZn could be maintained when uniaxial strain ratio increases from −7.28% to 9.59% and when c / a ratio ranges from 0.92 to 1.06. • The 100% spin polarization is preserved in V(Ti), Ni-Zn and V-Ti disordered structures. • The effect of various disorder on mechanical and thermodynamic properties is also studied in detail. The influence of atomic disorder on electronic, mechanical and thermodynamic properties of equiatomic quaternary all- d metal Heusler alloy NiVTiZn is studied by employing the first-principles calculations. The ground state of NiVTiZn is confirmed to be α -type structure with ferromagnetic nature, the calculated spin down energy gap and equilibrium lattice constant is ∼0.7 eV and 6.048 Å, respectively. The half metallicity could be maintained when uniaxial strain ratio increases from −7.28 % to 9.59 % and when c / a ratio ranges from 0.92 to 1.06, showing a robust half metallicity against the strain effect and tetragonal distortion. Six types of atomic swap disorder and twelve types of atomic antisite disorder are proposed. The V(Ni) and V(Zn) antisite disorders as well as V-Ni and V-Zn swap disorders are the most favorable owing to their negative formation energies. The 100 % spin polarization is preserved in V(Ti), Ni-Zn and V-Ti disordered structures although the width of band gap suffers contraction. The spin polarization of Ni(V), Ni(Zn), V(Zn) and Zn(Ni) disordered structures is also larger than 80 %. In addition, the effect of various disorder on mechanical and thermodynamic properties is also studied in detail. [ABSTRACT FROM AUTHOR]

Trilayer graphene exhibits valley-protected gapless states when the stacking order changes from ABC to CBA and a gate voltage is applied to outer layers. Some of these states survive strong distortions of the trilayer. For example, they persist when the outer layers are partially devoid yielding a system of two trilayers of different stacking order connected by a strip of a single graphene layer. Here we investigate how these states respond to another perturbation, i.e., the presence of magnetic defects, which we model as π -vacancies. We show that the gap states hybridize with the defect states and strongly spin-split. More importantly, it is demonstrated that by changing the gate voltage value one can change the spin density of the gap states and the corresponding currents at the Fermi level. [ABSTRACT FROM AUTHOR]

A possibility of appearance of antiferromagnetic ordering in armchair carbon nanotubes and graphene is studied using density functional theory within a DFT+U approach. It is shown that the Coulomb repulsion between electrons in the π -orbitals of graphene would need to reach a threshold value of U c = 3. 6 eV , in order to stabilize the antiferromagnetic order and an energy gap in an electron spectrum at the Fermi level. In the carbon nanotubes the threshold value U c for appearance of the antiferromagnetism decreases with the nanotube's diameter. For an intermediate value of U < U c the dependence of the energy gap on the diameter of nanotube is well described by a power law in agreement with earlier experimental findings. The antiferromagnetism in the carbon nanotubes is suppressed by departure of the Fermi level from a neutrality point. The latter result can qualitatively explain experimentally observed gate voltage dependence of the energy gap in junctions with the suspended carbon nanotubes as well as the absence of the energy gap in junctions with nanotubes deposited on some substrates. • Carbon nanotubes (CNTs) under influence of gate voltage are studied with a DFT+U method. • Hubbard U stabilizes an antiferromagnetic order with a quasiparticle energy gap in the CNTs. • The computations explain observed gate voltage dependence of the gap in ultraclean CNTs. [ABSTRACT FROM AUTHOR]

• Property of multicomponent soft magnetic alloy was predicted by first-principles calculation. • Complex competition exists among Fe, Ni, and Cr in affecting physical properties. • Relatively high contents of Fe and Cr is expected for great electromagnetic performance. • Ni is beneficial to enhancing the system stability of the face-centered cubic structure. • This work give a strategy for accelerated design of multicomponent soft magnetic alloy. Multicomponent alloys (MCAs) exhibit excellent soft magnetic properties and other service performance, and are promising for high-end applications. However, their complicated effects of element mixture and low efficiency in research and development could limit their industrialization. Hence, in this work, first-principles calculation was conducted on the relative formation energy, magnetism and density of states of Fe-Ni-Cr-Si-P-B-C-Nb MCAs for predicting its alloy stability, saturation magnetization (B s) and electric resistivity (ρ). The calculation results mainly present the mixture effects among Fe, Ni and Cr. There is a complex competition among Fe, Ni, and Cr elements in affecting the physical properties of the MCAs. The magnetism of the MCAs is not only determined by composition of magnetic elements but also by the coordination environment around the magnetic atoms. To achieve both high B s and high ρ in the Fe-Ni-Cr-Si-P-B-C-Nb system, proper addition of Fe and Cr may be expected. The optimized MCA has a relatively high B s nearly equal to the Fe-Si-Al system, and exhibits higher ρ and higher spin polarization. This indicates that the proposed MCAs are promising for both power devices and spintronic applications. This work gives a strategy for the property prediction and accelerated design of MCAs by first-principles calculation. It has promising potential to explore other element systems as for high-performance soft magnetic MCAs. [ABSTRACT FROM AUTHOR]

We consider a film of a topological insulator (TI) sandwiched between two ferromagnetic (FM) layers. The system is additionally under an external gate voltage. The surface electron states of TI are magnetized due to the magnetic proximity effect to the ferromagnetic layers. The magnetization of ferromagnetic layers can be changed by applying an external magnetic field or by varying thickness of the topological insulator (owing to the interlayer exchange coupling). The change in the magnetic configuration of the system affects the transport properties of the surface electronic states. Using the Green function formalism, we calculate spin polarization, anomalous Hall effect, and magnetoresistance of the system. We show, among others, that by tuning the gate voltage and magnetizations of the top and bottom FM layers, one can observe the topological transition to the quantum anomalous Hall state. • A topological insulator sandwiched between ferromagnetic layers is considered. • Two magnetization configurations of layers (parallel and antiparallel) are studied. • Switching between trivial and topological insulator state under gate voltage is discussed. [ABSTRACT FROM AUTHOR]

The spin-interdependent transport features for phosphorene superlattice, containing spin-flip and spin polarization are described under a constant electric field and extrinsic Rashba spin-orbit interaction utilizing the transfer matrix method. Our findings demonstrated the number of barriers at this structure acts the prominent role at the spin polarization and transmission probability, that can be applied in modeling optimum spintronic apparatus. Interestingly, the best outcomes for the transmission probability and spin polarization transpired in the five obstacles. Furthermore, an incoming electron with spin-up (down) can be transferred as an electron with spin-down (up) by adjusting the bias voltage and Rashba strength. Our findings can be utilized to create new nanostructures and maximize the performance of spintronic systems based on phosphorene nanoribbons. • The spin- independent transport features for a phosphorene superlattice, containing spin-flip and spin polarization have been studied under a constant electric field and extrinsic Rashba spin-orbit interaction utilizing the transfer matrix method. • The barriers number in the superlattice structure plays a dominant role in the spin polarization and transmission probability, that can be applied in modeling optimum spintronic apparatus. • By tuning the strength of external Rashba strength, and the bias voltage, it is possible to accurately control the conductance properties of the system and achieve high conductance which can be used in nano-electronic circuits and semiconductor devices. • The results show that by controlling the Rashba strength and the bias voltage, Spin Flip occurs. [ABSTRACT FROM AUTHOR]

Spintronic is the developing technology which probes the properties of quantum devices with spin of electrons which reduce the size and enhance its speed. Therefore, here the role of 5d electrons and thermoelectric characteristics of double perovskites (DPs) K 2 ZCl/Br 6 (Z = Ta, W, Re) elaborated comprehensively by density functional theory (DFT). The Heisenberg model spin polarization density (SP) has been applied to evaluate the Curie temperature (T c) and spin polarization factor. The tolerance factor (t F) and formation energy (ΔH) have been calculated to confirm the stability of structures. Ferromagnetism has been discussed in terms of spin polarization, crystal field energy (Δ CF) and exchange energies (Δ(d), Δ(pd)). The double exchange mechanism, and exchange constants ensure the role of electrons spin in ferromagnetism instead of segregation of transition metal ions. The transferring of magnetic moments of transitions metals to nonmagnetic sites (K, Cl, Br) show the exchange of spin of electrons and integer values of total magnetic moment show 100 % spin polarization. Finally, the transport properties are studied in standings of electrical and thermal conductivities. The large value of Seebeck coefficient and power factor ensure the importance of studied DPs for thermoelectric generators. • Spintronic and energy harvesting applications. • Large value of Curie temperature and high spin polarization. • The ferromagnetism by electron spin instead of magnetic ion clustering. • Half metallic ferromagnetism evidence complete spin polarization. • Ultralow low values of thermal conductivity and Large power factor. [ABSTRACT FROM AUTHOR]

The basis of spintronics is the technology involving nano-sized devices whose spins are directed. Therefore, materials that provide magnetic and 100 % spin polarization are remarkable. The ferromagnetic phase of VCo 2 O 4 has obtained the most stable. In the GGA approximation, the equilibrium lattice constant and magnetic moment values were 8.34 Å and 10.00 μ B /f.u., respectively. The band gaps in the GGA and GGA + mBJ approximations were calculated as 1.262 eV and 4.847 eV. The band gap values for Coulomb interactions U = 1, 2, 3, and 4 eV were obtained as 1.268 eV, 1.273 eV, 1.279 eV, and 1.286 eV, respectively. The elastic calculations showed that VCo 2 O 4 was mechanically stable and ductile. The Debye temperature was calculated as 565 K at 0 GPa pressure. As a result, VCo 2 O 4 oxide spinel has been obtained as a true half-metallic ferromagnetic material and will be a very good alternative for spintronic applications. [ABSTRACT FROM AUTHOR]

A model-independent irreducible tensor formalism is developed to analyse Ω ¯ Ω production in p ¯ p collisions and its subsequent decay via the triple-strange decay process, Ω ¯ + Ω − → K + Λ ¯ K − Λ → K + p ¯ π + K − p π −. These processes are relevant for the upcoming experiments at PANDA. We not only provide expressions for the density matrix of the Ω Ω ¯ system but also for the products at each stage of the decay. The Fano statistical tensors so obtained not only completely characterize the relevant final systems but also provide expressions for joint angular distributions. Finally, we show which of the Fano statistical tensors characterizing the Ω ¯ Ω system can be inferred from the Fano statistical tensors characterizing the final p ¯ p system, wherein we also obtain the relation between the production cross sections for Ω Ω ¯ and the final p p ¯ system. [ABSTRACT FROM AUTHOR]

Semiclassical expansion of the Wigner function for spin- 1 2 fermions having an effective spacetime-dependent mass is used to analyze spin-polarization effects. The existing framework is reformulated to obtain a differential equation directly connecting the particle spin tensor with the effective mass. It reflects the conservation of the total angular momentum in a system. In general, we find that the gradients of mass act as a source of the spin polarization. Although this effect is absent for simple boost-invariant dynamics, an extension to non-boost-invariant systems displays a non-trivial dependence of the spin density on the mass indicating that the spin polarization effects may be intertwined with the phenomenon of chiral restoration. [ABSTRACT FROM AUTHOR]

We study the effects of torsion as predicted by the Einstein-Cartan theory in the test-particle non-relativist approximation. We derive the corresponding 2-spinor Hamiltonian. Then, we solve an idealized reflection and transmission problem for a beam travelling across a spin-polarized target. We identify deviations in the spin polarizations on the reflected and transmitted beams that can distinguish Einstein-Cartan from general relativity. These deviations would constitute compelling evidence for a non-trivial spacetime torsion if measured. [ABSTRACT FROM AUTHOR]

Density of states and band structures reveals 100% spin polarization and half metallic ferromagnetism. [Display omitted] • The Half metallic ferromagnetism, and spintronic applications. • Magnesium ion battertties and energy storage. • The ferromagnetism due to electron spin as an alternative of magnetic ion clustering. • Above room temperarue Curie temperature and 100% spin polarization. • Ultralow low thermal conductivity and Large value of electrical conductivity. The ferromagnetism due to rare earth elements-based spinel chalcogenides has become emerging aspirant for spintronic devices. Therefore, theoretically computed electronic properties of MgTb 2 (S/Se) 4 spinels are analyzed to comprehend the structural, magnetic, and thermoelectric characteristics. Thermodynamic stability is elucidated using the computed enthalpy of formation (ΔH), phonons dispersion band structures. Using structural optimizations, difference in the energy states has revealed the ferromagnetic (FM) state stability. The computed band structures (BS) and density of states (DOS) both depict a half-metallic ferromagnetic state exhibiting a net spin polarization at the Fermi energy level. The underlying ferromagnetic state has been suggested due to carrier mediated indirect RKKY exchange mechanism. The thermoelectric properties are calculated to evaluate their potential for wasted-heat to useful-electricity conversion applications. The small thermal conductivity, and high-power factor exhibited by MgTb 2 S 4 at room temperature suggest it significant for applications in thermoelectric generators. [ABSTRACT FROM AUTHOR]

[Display omitted] • First-principles analysis to determine the impact of lanthanum (La) at the A-site and X (Ni, Co, Mn, Ti) at the B-site as mono- and co-dopants on spin-polarized electronic, structure and magnetic characteristics of Cubic BFO structure. • Calculations carried out in the Cambridge Serial Total Energy Package (CASTEP) code by using ultra-soft pseudopotential (USP) under GGA and LDA + U functionals. • The substitution of La and X atoms alters the spin-polarized electronic and dielectric characteristics of BFO, leading to an increase in the density of states (DOS) around the Fermi level. • LaCo and LaNi have shown have high spin polarizations of 87.08% and 82.20%. • Extremely low switching energies of 0.52 aJ and 0.72 aJ, respectively, observed for LaCo and LaNi co-doped BFO systems. In spintronic technology, bismuth ferrite BiFeO 3 (BFO) is a potential multiferroic material for multiferroic capacitor application. In present study, the impact of transition metals X = Co, Ni, Mn, Ti at the Fe-site and rare earth element lanthanum (La) at the Bi-site is investigated using DFT calculation in order to improve the structural stability, spin polarized electronic, and dielectric properties of bismuth ferrite for switching energy of multiferroic capacitor applications. The calculations are carried out in the Cambridge Serial Total Energy Package (CASTEP) code by using ultra-soft pseudopotential (USP). The substitution of La and X atoms alters the spin-polarized electronic and dielectric characteristics of BFO, leading to an increase in the density of states (DOS) around the Fermi level. The observed descending order of the structure stability of co-doped BFO is given as: LaCo > LaNi > LaMn co-doped BFO system. LaCo and LaNi co-substituted systems have shown high spin polarizations of 87.08 % and 82.20 % respectively. Low switching energies of 0.52 aJ and 0.72 aJ, respectively have been observed for LaCo and LaNi co-doped BFO systems for multiferroic RAM capacitor applications. [ABSTRACT FROM AUTHOR]

We investigated the degree of B2 order (S B2) of 4-10 nm-thick polycrystalline Co 2 (Mn 0.6 Fe 0.4)Ge (CMFG) Heusler alloy films using anomalous X-ray diffraction (AXRD) and its correlation to the magnitude of current-perpendicular-to-plane giant magnetoresistive (CPP-GMR) effect. We found that S B2 of the CMFG films is degraded for the film thickness below 6 nm, which is an issue for practical applications of CPP-GMR devices such as read head sensors of hard disk drives. Since S B2 has a thickness-dependence, the bulk spin polarization (β) of the CMFG layers is also expected to vary depending on the thickness; thus, the deduction of β using the Valet-Fert model, where β is assumed to be thickness-independent, is not valid for these CPP-GMR devices. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The structure, electrical transport, and magnetic properties have been systematically studied in superconducting Ti 1− x Mg x O (x = 0, 0.003, 0.02, 0.08, and 0.27) films. It is found that, both the zero resistance and onset superconducting transition temperatures of Ti 1− x Mg x O first increase with increasing the Mg content from x = 0 to x = 0.02, and then decrease with the further increase of x. More interestingly, the Mg-doping simultaneously introduces a ferromagnetic order into this superconducting system, and the ferromagnetism gradually increases with increasing Mg content. According to the first-principles calculations, the non-monotonous Mg doping-dependent superconductivity, carrier density, and disorder strength may be explained as that the Mg atoms first fill the Ti vacancy sites and then substitute the Ti atoms. The calculations also reveal that the ferromagnetism is highly related to the spin polarization of 3 d states of Ti atoms surrounding Mg atoms. The discovery of enhanced superconductivity with coexisting ferromagnetism in Ti 1− x Mg x O films provides an excellent platform to investigate the interaction between superconductivity and ferromagnetism. Image, graphical abstract [ABSTRACT FROM AUTHOR]

We investigate the production of spin-polarized currents in corrugated graphene nanoribbons. Such corrugations are modeled as multiple regions with Rashba spin-orbit interactions, where concave and convex curvatures are treated as Rashba regions with opposite signs. Numerical examples for different separated Rashba-zone geometries calculated within the tight-binding approximation are provided. Remarkably, the spin-polarized current in a system with several Rashba areas can be enhanced with respect to the case with a single Rashba part of the same total area. The enhancement is larger for configurations with multiple regions with the same Rashba sign. This indicates that the increase of the spin polarization is due to the scattering of the electrons traversing regions with and without Rashba interaction. Additionally, we relate the appearance of the spin-polarized currents to novel symmetry relations between the spin-dependent conductances. These symmetries turn out to be a combination of different symmetry operations in real and spin spaces, as those occurring in non-planar systems like carbon nanotubes. Our results show that two-dimensional devices with Rashba spin-orbit interaction can be used as excellent spintronic devices in an all-electrical or mechanical setup. Image 1 [ABSTRACT FROM AUTHOR]

A sealed positron source that can sufficiently reduce the backscattered component was fabricated using an aqueous 22 NaCl solution and a graphite backing material. The spin polarization of the emitted positrons was evaluated as 39%, which was 1.7 times higher than that of a commercial source with a heavy-metal backing material. This source increased the amplitude of the magnetic Doppler broadening spectrum for ferromagnetic iron. [ABSTRACT FROM AUTHOR]

It is well known that intercalated species can strongly affect the graphene-substrate interaction. As repeatedly shown by experiment and theory, the intercalation of atomic species may establish a free-standing character in chemisorbed graphene systems. Here, we focus on graphene grown on a strongly interacting support, cobalt, and demonstrate that the film electronic structure and doping can be tuned via the intercalation/removal of interfacial oxygen. Importantly, cathode lens microscopy reveals the main mechanism of oxygen intercalation, and in particular how microscopic openings in the mesh enable oxygen accumulation at the graphene-cobalt interface. Our experiments show that this process can be carefully controlled through temperature, without affecting the film morphology and crystalline quality. The presence of oxygen at the interface induces an upward shift of the graphene π band, moving its crossing above the Fermi level, accompanied by an increased Fermi velocity and reduced momentum width. Control on the graphene coupling to cobalt may enable one to alter the induced spin polarization in graphene's electronic states. Image 1 [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]

In this research, high–density La 0.67 (Ca 0.24 Sr 0.09)MnO 3 : x Ag 2 O (LCSMO: x Ag 2 O, x = 0, 0.05, 0.1. 0.15, 0.2, and 0.25) composites were successfully fabricated through the conventional sol-gel method. Scanning electron microscopy (SEM), X–ray photoelectron spectroscopy (XPS) and XRD data confirmed presence of silver at A sites (La3+/Ca2+/Sr2+) as Ag+ and segregates at grain boundaries (GBs) to form metallic silver. The electrical properties greatly improved by adding Ag 2 O. Significant enhancements in peak temperature coefficient of resistivity (TCR) and magnetoresistance (MR) at room–temperature (300 K) were observed for LCSMO: x Ag 2 O composites. The peak TCR increased from 3.7% K−1 (299.3 K, for x = 0) to 14.8% K−1 (301.0 K, for x = 0.2), and MR rose from 16.9% (303.0 K, for x = 0) to 34.1% (300.6 K, for x = 0.2). These improvements in peak TCR were attributed to increased grain size and formation of metallic silver at GBs or within the composites. Moreover, peak MR was higher in Ag 2 O doped composites, which was mainly due to large spin polarization effect and strong coupling ferromagnetic domains under external magnetic field. Overall, the large room-temperature TCR and MR values of LCSMO:0.2Ag 2 O composites look promising for future advanced uncooling infrared bolometers and magnetic sensors. Unlabelled Image • Room-temperature TCR increased from 3.7% K−1 (for LCSMO) to 14.8% K−1 (for LCSMO:0.2Ag 2 O). • Room-temperature MR rose from 16.9% (for LCSMO) to 34.1% (for LCSMO:0.2Ag 2 O). • LCSMO:0.2Ag 2 O composites look promising for uncooling infrared bolometers or magnetic sensors. [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]

[Display omitted] The quaternary Heusler alloys with composition LiAEFeSb have been studied in this manuscript (AE = Alkaline Earth elements Be, Mg, Ca, Sr and Ba) for their potential applications in spintronics. All the investigations have been performed by employing density functional theory. A systematic comparison of results obtained within local density approximation (LDA) and the generalized gradient approximation (GGA) done. Our calculations reveal that all the studied alloys have lowest energy in type-I arrangement of basis and exhibit interesting electronic and magnetic properties. All the alloys exhibit a stable ferromagnetic ground state. Fixed spin moment calculations rule out existence of any other local magnetic minima. The phonon dispersions show that all the alloys except LiBeFeSb are dynamically stable. Notably, LiSrFeSb and LiBaFeSb exhibit half-metallic electronic band structure and 100 % spin polarization making them suitable choice for promising spintronic applications such as spin filter and detectors. [ABSTRACT FROM AUTHOR]

The spintronic is an emerging technology which controls the properties of multifactional devices with spin of electrons. In present manuscript, Wien2k and Boltz Trap codes are used to explore electronic, magnetic, and thermoelectric characteristics of Sr 2 CrXO 6 (X = Nb, Mo) double perovskites (DPs). The evaluation of energies released in paramagnetic (PM), antiferromagnetic (AFM), and ferromagnetic (FM) states assure the stability of FM states. Both the negative formation energy and the tolerance factor confirm structural and thermodynamic stability in FM states. The 100 % spin polarization was confirmed by both integer values of magnetic moment (MM) and the spin polarization factor. The values of exchange energy, double exchange model, hybridization of p-d states, and exchange constants are calculated to explore the nature of ferromagnetism and spin functionality. The effect of thermoelectric parameters on spin of electrons and thermoelectric performance are elaborated by thermal to electrical conductivity ratio, Seebeck coefficient and power factor. • High Curie temperature, and spintronic applications. • Spin of electrons overcome the charge with multifuctional properties. • Double exchange mechanism confirms the ferromagnetism by electron spin instead of magnetic ion clustering. • Half metallic ferromagnetism and 100 % spin polarization. • Large value of electrical conductivity and low values of thermal conductivity. [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]

Bilinear magnetoresistance has been studied theoretically in 2D systems with isotropic cubic form of Rashba spin–orbit interaction. We have derived the effective spin–orbital field due to current-induced spin polarization and discussed its contribution to the unidirectional system response. The analyzed model can be applied to the semiconductor quantum wells as well as 2DEG at the surfaces and interfaces of perovskite oxides. • Magnetoresistance (MR) is studied in 2DEG with cubic Rashba spin-orbit interaction. • MR contains a term, that scales linearly with in-plane magnetic field and current. • Bilinear MR results from spin-orbital field due to current-induced spin polarization. [ABSTRACT FROM AUTHOR]

We theoretically study the influence of an external magnetic field on the transport properties of a double quantum dot (DQD)-Majorana nanowire system in a cross-shaped configuration with central dot coupled to a superconductor and normal metallic leads. In such a system, we can observe a subtle interplay between generation of Andreev bound states, Majorana mode leaking into quantum dots and interdots Fano-like interference processes. We show that properly selected side-coupled quantum dot energy can slow down/activate the process of Majorana mode leaking into DQD and additionally can strongly affect the differential and linear conductance in the considered system. We also study the influence of spin polarization of quantum dot–Majorana mode coupling on the transport properties of the considered system, especially on its linear conductance. • The theoretical model of a double quantum dot coupled to a Majorana nanowire system in a cross-shaped configuration is analyzed. • Strong competition between Majorana mode leaking into quantum dots and interdots Fano-like interference processes are observed. • The spin polarization of quantum dot–Majorana mode coupling affects the differential conductance. [ABSTRACT FROM AUTHOR]

• DFT calculations were used to study the magnetic properties of the Fe 2 MnAs alloy. • The influence of point defects on these properties were investigated. • The formation energy, density of states, and magnetic moments, were computed. • The contraction of the lattice enhance the spin polarization of the Fe 2 MnAs alloy. • The defects of Mn As , Mn ↔ As, V As , and V Mn exhibit 100% spin polarization. First-principles calculations within the framework of the density functional theory were conducted using the FP-LAPW method to investigate the electronic and magnetic properties of the Full-Heusler Fe 2 MnAs alloy. The study encompassed the examination of its perfect structure as well as the variation of lattice constants around the ground state. The negative value of the calculated formation energy suggests that the alloy may form spontaneously. From a magnetic perspective, Fe 2 MnAs exhibit a ferromagnetic order. The alloy also shows a high spin-polarization that may be increased, transforming the alloy into a half-metal, with the contraction of the lattice constant. Furthermore, the investigation delved into the effect of point defect formation. The calculated formation energies for vacancies, antisite, and exchange defects suggest the likely occurrence of some of these defects within the Fe 2 MnAs compound. Significantly, certain defects contribute to the spin-polarization of the alloy, effectively rendering it a fully half-metallic material. [ABSTRACT FROM AUTHOR]

• An effect of oxygen vacancy on the electronic and magnetic properties of copper pyrophosphate compound was investigated using DFT calculations. • The vacancy presence reduced the gap width from 2.17 eV to 0.19 eV, changing its character from indirect to direct. • The oxygen vacancies slightly modify the spin polarization of d-orbitals of Cu atoms neighboring the vacancy, resulting in the non-zero total magnetic moment of 0.19 µB/FU. The effect of oxygen vacancies (V O) on the electronic and magnetic properties of copper pyrophosphate dihydrate Cu 2 P 2 O 7 *2H 2 O (CuPPD) semiconductors is studied employing the DFT-based ab initio pseudopotential method. Site preference for vacancy formation on the selected oxygen sublattices is analyzed. Investigations revealed that the V O vacancies led to narrow bands of hybridized Cu-3d and O-2p states within the energy gap of perfect CuPPD semiconductors, significantly reducing the gap width from 2.17 eV to 0.19 eV and changing its character from indirect to direct one. Calculations have shown that the vacancies have no significant influence on the ferrimagnetic structure of CuPPD. The magnetic properties are driven by local magnetic moments of Cu atoms pointed oppositely. The oxygen vacancies slightly modify the spin polarization of d-orbitals of Cu atoms neighboring the vacancy, resulting in the non-zero total magnetic moment of 0.19 µ B /FU (0.0 µ B /FU in perfect CuPPD). The study's main finding, which can be exploited in nanoelectronics, is that the controlled implementation of oxygen vacancies can regulate the energy gap of CuPPD semiconductors. [ABSTRACT FROM AUTHOR]

The particles in the honeycomb lattice with on-site s -wave pairing exhibit many interesting behaviors, which can be described in the framework of the Hubbard model. Among others, at the half-filling, some critical value | U c | of pairing interaction U < 0 exists that, for U < U c , the superconducting phase becomes unstable. Introduction of the nonzero hopping t ′ between next-nearest-neighbor sites strongly modifies the physical properties of the system. Here, we discuss the behavior of the system for t ′ ≠ 0 (at the ground state), where the hopping between next-nearest neighbors leads to change of the order of phase transition between superconducting and normal phases from discontinuous to continuous one in the external magnetic field h. We show that this behavior is strongly dependent on t ′ and associated with the Dirac cones in the non-interacting band structure of the system. For non-zero magnetic field and for some range of t ′ , a spin-polarized superconducting phase occurs in the ground state phase diagram (only at the half-filling and for h ≠ 0). • Ground state of the Hubbard model in the external magnetic field is investigated. • Effects of the next-nearest-neighbor hopping are investigated on the honeycomb lattice. • Two different superconducting phases are found to be stable. • The spin-polarized superconducting (so-called Sarma) phase occurs in the field. • The ground state phase diagrams of the model are determined. [ABSTRACT FROM AUTHOR]

The double perovskites (DPs) have become emerging aspirant for spintronic technology because of their stable, and multifunctional properties. Here in present article, the role 5d-electrons of Ta, W, Re, and Os in ferromagnetism, and thermoelectric behavior has been illustrated briefly. The ideal values of tolerance factor, formation energy and phonons dispersions are reported for structural, thermodynamic, and lattice dynamic stabilities. The higher Curie temperature and spin polarization has been addressed by Heisenberg model and spin density calculations. The ferromagnetism has been explained by the metallic and insulating channels of spin up and spin down configuration through hybridization, exchange energies, and exchange constants. The shifting of magnetic moments from Cr and X sites to Ba, O and interstitial sites ensures the exchange coupling due to spin of electrons rather than clustering. Furthermore, thermoelectric effect on the spin degree of electrons and transport characteristics are calculated by BoltzTraP code. • Above room temperature ferromagnetism. • Spin of electrons dominant the charge. • Electron spin instead of magnetic ion clustering. • Half metallic ferromagnetism evidence 100% spin polarization. • Ultralow low values of thermal conductivity. [ABSTRACT FROM AUTHOR]

Herein, the magnetic field facilitated electrocatalytic degradation of tetracycline is reported for the first time. A magnetic porous carbonized phthalonitrile resin electrocatalyst has been prepared through directly annealing phthalonitrile monomer, polyaniline coated barium ferrite and potassium hydroxide. The tetracycline degradation percentage (DP%) by such electrocatalyst is significantly increased up to 37.42% under magnetic field with the optimal pH value of 5.0 and bias voltage of 1.0 V (vs. SCE). The mechanism of this phenomenon is explained by the spin-selective electron removal process in the reaction between metal-oxygen species and tetracycline on the electrocatalyst. The comparison of degradation pathways for tetracycline with and without magnetic field confirms the improvement of tetracycline DP%. This work opens a new direction for the application of an external magnetic field in the electrocatalytic degradation of antibiotics in wastewater. [Display omitted] • A novel magnetic porous carbonized phthalonitrile resin was successfully prepared. • Magnetic field enhanced electrocatalytic degradation of tetracycline was observed. • Spin-selective electron removal process was proposed in tetracycline degradation. • Degradation pathways with/without magnetic field affirmed the boost of degradation. [ABSTRACT FROM AUTHOR]

Magnetic field gradients interfere with the coherence of the atomic ensemble and degrade the performance of the spin-exchange relaxation-free (SERF) atomic magnetometer. In this paper, the influence of magnetic field gradients is incorporated into the response model of single-beam atomic magnetometer, and the theoretical models of transverse relaxation rate, spin polarization and scale factor are established. Based on this model, we find that magnetic field gradients in different directions can cause varying degrees of degradation in the performance parameters of the magnetometer. The magnetic linewidths under different light power and magnetic field gradients are measured using the designed dedicated magnetic field gradients coils, and the spin polarization and magnetic field gradients relaxation rate are obtained through fitting. An unevenness and deviation of the curve are also observed in the experiments, indicating the presence of the magnetic field gradient of approximately 2 nT/cm in the magnetic shields. Furthermore, in a magnetic field gradient environment of 20 nT/cm, the mean of the long-term sensitivity decreased by 3.5 times and the standard deviation increased by 11 times. It shows that the magnetic field gradients will not only affect the signal-to-noise ratio, but also make the magnetometer more vulnerable to external interference when working. The sensitivity and stability of magnetometer will be greatly reduced. The research in this article provides a theoretical and experimental basis for eliminating the influence of magnetic field gradients and improving the accuracy of magnetic field measurements. • The models of the influence of MFGs on the parameters of the OPMs are established. • The experimental results are in good agreement with the proposed equations. • The asymmetry of the curve indicates the presence of residual MFGs. • The MFGs make the OPM more vulnerable to interference from the external environment. [ABSTRACT FROM AUTHOR]

Coherent spin transport in a protein containing the [4Fe-4S] cluster were calculated by using NEGF-DFT based on the Landauer model. The results of the spin transmission pathway revealed spin flow via Fe-S clusters. [Display omitted] • Spin transport in an Fe-S protein based on the Landauer formula. • Difference of tunneling characteristics due to oxidized and reduced states. • Spin transmission pathway via Fe-S clusters. Spin transport in a molecule was recently examined to discuss the chiral-induced spin selectivity (CISS) effect. This effect has been particularly reported in metalloproteins because the presence of transition metals improves spin polarization in a helical peptide structure. Among metalloproteins, iron-sulfur proteins have ubiquitous redox properties in photosynthesis and respiration. Iron can enhance spin polarization. In this study, the coherent spin transport in an Fe-S protein was investigated using first-principles calculations based on the Landauer formula. Proteins containing the [4Fe-4S] cluster were used for the calculations. The results of the spin transmission pathway revealed spin flow via Fe-S clusters. [ABSTRACT FROM AUTHOR]

• A dynamical study at atomistic-scale on the behavior of non-collinear antiferromagnetic Mn 3 Pt driven by current-induced spin orbit torque. • Two different field-free magnetic excitation modes can be achieved in W/Mn 3 Pt heterostructures with varying crystalline direction. • Oscillation frequency depends on the injected current density as well as the antiferromagnetic layer's thickness. Current-induced spin–orbit torque (SOT) enables highly efficient manipulation of magnetic orders. Non-collinear antiferromagnets exhibit ultrafast spin dynamics by SOT with much higher oscillation frequency than ferromagnets, offering potential applications in terahertz spintronic devices. In this study, we used atomistic scale Landau-Lifshitz-Gilbert simulation approach to demonstrate different magnetic excitation modes in W/Mn 3 Pt heterostructures with varying crystalline direction. When the spin polarization is perpendicular to the Kagome plane of Mn 3 Pt, all the magnetic Mn atoms oscillate periodically within the Kagome plane around the normal direction. In contrast, when the spin polarization is parallel to the Kagome plane, only two neighboring Mn atoms rotate while another neighboring Mn atom remains immobile. Interestingly, both of these magnetic excitation modes have the same frequencies and occur in the terahertz range. Additionally, the frequency is proportional to current density and inversely proportional to the antiferromagnetic layer thickness. These findings provide a deeper understanding of magnetic excitation properties in non-collinear antiferromagnets, which can inform the design of terahertz spintronic devices. [ABSTRACT FROM AUTHOR]