Search

This study employs a first-principles approach to comprehensively examine the structural, electronic, optical, and magnetic properties of the thermodynamically stable scintillating double perovskite halides A 2 N a T a X 6 ( A = C s , R b ; X = C l , B r , I ). The dynamic stability of these materials were explained based on deduced phonon properties. Our analysis reveals that these compounds exhibit intriguing electronic behavior with spin polarization, demonstrating half-metallicity. In spin-up, the band gap is found to be zero, while in spin-down, it falls within the range of 3 to 4 eV with the incorporation of DFT+U corrections. Notably, the optical properties assessment highlights the exceptional UV and high-energy absorption capabilities of A 2 N a T a I 6 , making it a promising candidate for scintillation applications in particle detection. This research sheds light on the unique and versatile properties of these materials, with implications for various technological and scientific applications. [ABSTRACT FROM AUTHOR]

Metabolism is a fundamental process that underlies human health and diseases. Nuclear magnetic resonance (NMR) techniques offer a powerful approach to identify metabolic processes and track the flux of metabolites at the molecular level in living systems. An in vitro study through in-cell NMR tracks metabolites in real time and investigates protein structures and dynamics in a state close to their most natural environment. This technique characterizes metabolites and proteins involved in metabolic pathways in prokaryotic and eukaryotic cells. In vivo magnetic resonance spectroscopy (MRS) enables whole-organism metabolic monitoring by visualizing the spatial distribution of metabolites and targeted proteins. One limitation of these NMR techniques is the sensitivity, for which a possible improved approach is through isotopic enrichment or hyperpolarization methods, including dynamic nuclear polarization (DNP) and parahydrogen-induced polarization (PHIP). DNP involves the transfer of high polarization from electronic spins of radicals to surrounding nuclear spins for signal enhancements, allowing the detection of low-abundance metabolites and real-time monitoring of metabolic activities. PHIP enables the transfer of nuclear spin polarization from parahydrogen to other nuclei for signal enhancements, particularly in proton NMR, and has been applied in studies of enzymatic reactions and cell signaling. This review provides an overview of in-cell NMR, in vivo MRS, and hyperpolarization techniques, highlighting their applications in metabolic studies and discussing challenges and future perspectives. [ABSTRACT FROM AUTHOR]

We experimentally investigate magnetization reversal curves for a GeTe topological semimetal. In addition to the known lattice diamagnetic response, we observe narrow magnetization loop in low fields, which should not be expected for non-magnetic material. The diamagnetic hysteresis loop is unusual, so the saturation level is negative in positive fields, and the loop is passed clockwise, in contrast to standard ferromagnetic behavior. We show, that the experimental hysteresis curves cannot be obtained from standard ferromagnetic ones by adding/subtracting of any linear dependence, or even by considering several interacting magnetic phases. The latter possibility is also eliminated by the remanence plots technique (Henkel or plots). We explain our results as a direct consequence of the correlation between ferroelectricity and spin-polarized surface states in GeTe, similarly to magnetoelectric structures. [ABSTRACT FROM AUTHOR]

Emergent phenomena such as two-dimensional electron gas (2DEG) and interfacial superconductivity and ferromagnetism are generally built on the interface between insulating oxide thin films and substrates, e.g., LaAlO3/SrTiO3, where the 2D profiles of these electronic states are precisely confined at the interface of two insulators. Herein we report a high-mobility electron gas state with unusual symmetry at the interface of the Sr2CrMoO6/SrTiO3 (110) heterostructures, the fermiology of which follows the cubic crystallographic symmetry rather than the two-dimensional interface itself, resulting in the identical Shubnikov-de Haas oscillations with applied magnetic field along all the twelve equivalent [110] crystallographic directions of SrTiO3, distinctly different from the 2D nature of the electron gas reported previously. Neutron diffraction verifies the predicted ferrimagnetic ordering between Cr and Mo moments. This, together with the magnetic hysteresis loops and negative magnetoresistance in low-field region, suggests possible spin polarization of itinerant electrons. Therefore, a quasi-3D profile, high mobility (up to 104 cm2 V−1 s−1) and possibly spin polarized electronic state is observed in the double-perovskite-based oxide heterostructures. This finding of the electronic properties in Sr2CrMoO6/SrTiO3 (110) heterostructure expands the knowledge of interfacial physics, as well as shines light on oxide-based electronics and spintronics research. The existence of electron gas at the interfaces of oxide-based heterostructures with broken spatial inversion symmetry gives rise to various interesting physical phenomena. Here, the authors report a new type quasi-three-dimensional electron gas state at the interface of ferrimagnetic semiconductor-strontium titanate heterostructures, which show high mobility, high valley degeneracy and possible spin polarization. [ABSTRACT FROM AUTHOR]

Half-metallic ferromagnetic Heusler alloys attracted much attention in the last few decades due to their significant physical properties as well as its potential applications in spintronic devices. To explore and predict the various physical properties of Co-based Heusler alloy, Co2MnSi (CMS), First principles calculations are of interest and has been used in the present study. Optimized E–V curves represent that CMS alloy is most stable in its magnetic L21 structural phase. The electronic charge density plot represents the ionic bonding along with co-valent character for the compound. DOS and BS calculations shows 100% spin polarization at Fermi level (EF) which confirms the half metallic character of the compound. DOS exhibited the prominent role of Co-3d and Mn-3d electronic states along with Si-2p electronic states. Estimated magnetic moment of Co2MnSi Heusler alloy was found to be ~ 5μB per f. u. which is in line with the Slater-Pauling behaviour. Dynamical stability of Co2MnSi Heusler alloy has also been verified by the phonon dispersion curves which revealed that compound is dynamically stable. Additionally, the physical properties have also been explored as a consequence of SOC and significant changes in electronic and optical properties were observed. The observed significant results of electronic, magnetic, and optical properties of CMS Heusler alloy makes it promising towards potential application in optical and spintronic devices. [ABSTRACT FROM AUTHOR]

Polarization and spin correlations have been studied in detail for top quarks at the LHC, but have been explored very little for the other flavors of quarks. In this paper we consider the processes pp → with q = b, c or s. Utilizing the partial preservation of the quark's spin information in baryons in the jet produced by the quark, we examine possible analysis strategies for ATLAS and CMS to measure the quark polarization and spin correlations. We find polarization measurements for the b and c quarks to be feasible, even with the currently available datasets. Spin correlation measurements for are possible using the CMS Run 2 parked data, while such measurements for will become possible with higher integrated luminosity. For the s quark, we find the measurements to be challenging with the standard triggers. We also provide leading-order QCD predictions for the polarization and spin correlations expected in the and samples with the cuts envisioned for the above analyses. Apart from establishing experimentally the existence of spin correlations in and systems produced in pp collisions, the proposed measurements can provide new information on the polarization transfer from quarks to baryons and might even be sensitive to physics beyond the Standard Model. [ABSTRACT FROM AUTHOR]

With the field correlator method (FCM) for QCD, we show that the chiral vortical effect (CVE) in hot (strongly-interacting) quark-gluon plasma ((s)QGP) is modified by non-perturbative interactions – by color-magnetic confinement, and by remnant color-electric interaction, which is encoded in the Polyakov line. The obtained result demonstrates numerical suppression of CVE comparable to the phenomenological suppression used for numerical simulations of RHIC-STAR data on hyperons spin polarization in non-central heavy ion collision (HIC). The parameters range in the temperature – quark chemical potential plane is expected to cover ALICE and RHIC data. The chiral current is calculated for the rigidly rotating model of (s)QGP in the linear order in angular velocity at the rotation axis with account of non-perturbative interactions. [ABSTRACT FROM AUTHOR]

We have looked at a very interesting class of Heusler alloy that has received a lot of theoretical research but a very little experimental attention. Mn2TiSi Heusler alloy was synthesized by a conventional vacuum arc remelting process. The formation of Heusler phase along with the secondary phases was observed after annealing it at 773 K for 120 h. The X-ray diffraction pattern illustrates the presence of cubic B2 disordered phase along with a secondary phase with a lattice parameter of 5.82 Å. The microstructure and compositional analysis of Mn2TiSi alloy shows the presence of distribution of Mn, Ti, and Si elements according to their stoichiometric ratio. The magnetic measurements show a ferromagnetic nature with Curie temperature (TC) around 203 K. With low magnetic moment and coercivity, Mn2TiSi can be used for switching applications because of its fast magnetization reversal. So, Mn2TiSi becomes the greatest choice for use in spintronics due to its low magnetic moment and low coercivity. [ABSTRACT FROM AUTHOR]

Electret fiber filtration materials prepared by electrostatic spinning and corona polarization have drawn significant interest in treating radioactive aerosols. In this study, a three-dimensional biomass-based electret nanofiber aerogel material with high dust capacity, high filtration efficiency and low-pressure drop was created by pore structure regulation. The results showed that aerogels with good charge capture and storage ability were obtained by regulating the concentration of tert-butanol and ethylcellulose fiber suspension, and the pre-freezing temperature. The initial surface potential and stable surface potential increased from 0.85 and 0.05 kV to 1.37 and 0.15 kV respectively. Furthermore, the purification time was reduced from 44 to 15 min. [ABSTRACT FROM AUTHOR]

Calculations of electron–nuclear alignment (CIDEP multiplet effect) in radicals formed as a result of the photochemical decomposition of molecules have been performed. There is a mutual ordering of spins in the radicals: the electron and nuclear spins in the radical are oriented parallel or antiparallel. The populations of stationary states of radicals in weak magnetic fields have been calculated in the framework of the kinematic approach. [ABSTRACT FROM AUTHOR]

In the present work, we investigate the electronic structure and magnetism of InN nanoribbon doped with 3d Mn atoms in different positions by first-principle density functional calculations. The structural stability is described by using the calculated total energy of the doped nanoribbons including the antiferromagnetic (AFM) and the ferromagnetic (FM) coupled states. Our calculations show that the ground state is ferromagnetic regardless of the position of Mn atoms. The dependence of bandgap and spin polarization on Mn positions makes it possible to control the electronic properties by choosing the impurity position and applying these structures in nanoelectronics and spintronics. [ABSTRACT FROM AUTHOR]

We predict a series of XYZ-type half-Heusler RuMnZ (Z = Si, Ge, Sn, P, As, Sb, Se, and Te) alloys, using density functional theory (DFT) calculations. Structural, electronic structure, magnetic moments, and elastic properties are carried out using both GGA and GGA+U approximations to determine the viability of this series of alloys for spintronic applications. The band structure (BS) and density of states (DOS) calculations are carried out to explain the half-metallic and magnetic nature of the predicted alloys. RuMnZ alloys stabilize to the F 4 ¯ 3 m space group with a ferrimagnetic (FiM) ground state, with the exception of RuMnSn, which has a ferromagnetic (FM) ground state. Interestingly, RuMnP/As/Te alloys exhibit half-metallic properties with 100% spin polarization at the Fermi level among the predicted alloys. When U is included in the calculations (GGA+U), the half-metallicity is completely lifted. Further, upon incorporating pressure under GGA+U, a band gap is induced again, and the half-metallicity in RuMnTe is robust up to a compressive pressure of 140 GPa. Calculation of the elastic properties shows that RuMnZ has a ductile nature. [ABSTRACT FROM AUTHOR]

We investigate the anomalous W - W + γ / Z couplings in e - e + → W - W + followed by semileptonic decay using a complete set of polarization and spin correlation observables of W boson with the longitudinally polarized beam. We consider a complete set of dimension-six operators affecting W - W + γ / Z vertex, which are S U (2) × U (1) gauge invariant. Some of the polarization and spin correlation asymmetries average out if the daughter of W + is not tagged and to overcome this we developed an artificial neural network and boosted decision trees to distinguish down-type jets from up-type jets. We obtain bounds on the anomalous couplings using MCMC analysis at s = 250 GeV with integrated luminosities of L ∈ { 100 fb - 1 , 250 fb - 1 , 1000 fb - 1 , 3000 fb - 1 } and different sets of systematic errors. We find that using spin-related observables along with cross section in the presence of initial beam polarization significantly improves the bounds on anomalous couplings compared to previous studies. [ABSTRACT FROM AUTHOR]

We experimentally investigate charge transport in In–GeTe and In–GeTe–In proximity devices, which are formed as junctions between superconducting indium leads and thick single crystal flakes of α-GeTe topological semimetal. We observe nonmonotonic effects of the applied external magnetic field, including reentrant superconductivity in In–GeTe–In Josephson junctions: supercurrent reappears at some finite magnetic field. For a single In–GeTe Andreev junction, the superconducting gap is partially suppressed in zero magnetic field, while the gap is increased nearly to the bulk value for some finite field before its full suppression. We discuss possible reasons for the results obtained, taking into account spin polarization of Fermi arc surface states in topological semimetal -GeTe with a strong spin–orbit coupling. In particular, the zero-field surface state spin polarization partially suppresses the superconductivity, while it is recovered due to the modified spin-split surface state configuration in finite fields. As an alternative possible scenario, the transition into the Fulde–Ferrell–Larkin–Ovchinnikov state is discussed. However, the role of strong spin–orbit coupling in forming the nonmonotonic behavior has not been analyzed for heterostructures in the Fulde–Ferrell–Larkin–Ovchinnikov state, which is crucial for junctions involving GeTe topological semimetal. [ABSTRACT FROM AUTHOR]

A domain wall (DW) which moves parallel to a magnetically compensated interface between an antiferromagnetic insulator (AFMI) and a two-dimensional (2D) metal can pump spin polarization into the metal. It is assumed that localized spins of a collinear AFMI interact with itinerant electrons through their exchange interaction on the interface. We employed the Keldysh formalism of Green's functions for electrons which experience potential and spin-orbit scattering on random impurities. This formalism allows a unified analysis of spin pumping, spin diffusion and spin relaxation effects on a 2D electron gas. It is shown that the pumping of a nonstaggered magnetization into the metal film takes place in the second order with respect to the interface exchange interaction. At sufficiently weak spin relaxation this pumping effect can be much stronger than the first-order effect of the Pauli magnetism which is produced by the small nonstaggered exchange field of the DW. It is shown that the pumped polarization is sensitive to the geometry of the electron's Fermi surface and increases when the wave vector of the staggered magnetization approaches the nesting vector of the Fermi surface. In a disordered diffusive electron gas the induced spin polarization follows the motion of the domain wall. It is distributed asymmetrically around the DW over a distance which can be much larger than the DW width. [ABSTRACT FROM AUTHOR]

The effective mass at the Fermi level is measured in the strongly interacting two-dimensional (2D) electron system in ultra-clean SiGe/Si/SiGe quantum wells in the low-temperature limit in tilted magnetic fields. At low electron densities, the effective mass is found to be strongly enhanced and independent of the degree of spin polarization, which indicates that the mass enhancement is not related to the electrons' spins. The observed effect turns out to be universal for silicon-based 2D electron systems, regardless of random potential, and cannot be explained by existing theories. [ABSTRACT FROM AUTHOR]

The role of spin–orbit interaction has been recently reconsidered in high- T c cuprates, stimulated by the recent experimental observations of spin-polarized electronic states. However, due to the complexity of the spin texture reported, the origin of the spin polarization in high- T c cuprates remains unclear. Here, we present the spin- and angle-resolved photoemission spectroscopy (ARPES) data on the facing momentum points that are symmetric with respect to the Γ point, to ensure the intrinsic spin nature related to the initial state. We consistently found the very weak spin polarization only along the nodal direction, with no indication of spin-splitting of the band. Our findings thus call for a revision of the simple application of the spin–orbit interaction, which has been treated within the standard framework of the Rashba interaction in high- T c cuprates. [ABSTRACT FROM AUTHOR]

The effective mass at the Fermi level is measured in the strongly interacting two-dimensional (2D) electron system in ultra-clean SiGe/Si/SiGe quantum wells in the low-temperature limit in tilted magnetic fields. At low electron densities, the effective mass is found to be strongly enhanced and independent of the degree of spin polarization, which indicates that the mass enhancement is not related to the electrons' spins. The observed effect turns out to be universal for silicon-based 2D electron systems, regardless of random potential, and cannot be explained by existing theories. [ABSTRACT FROM AUTHOR]

We examine the impact of spin effects on the nonequilibrium transport properties of a nanowire hosting Majorana zero-energy modes at its ends, coupled to a quantum dot junction with ferromagnetic leads. Using the real-time diagrammatic technique, we determine the current, differential conductance and current cross-correlations in the nonlinear response regime. We also explore transport in different magnetic configurations of the system, which can be quantified by the tunnel magnetoresistance. We show that the presence of Majorana quasiparticles gives rise to unique features in all spin-resolved transport characteristics, in particular, to zero-bias anomaly, negative differential conductance, negative tunnel magnetoresistance, and it is also reflected in the current cross-correlations. Moreover, we study the dependence of the zero-bias anomaly on various system parameters and demonstrate its dependence on the magnetic configuration of the system as well as on the degree of spin polarization in the leads. A highly nontrivial behavior is also found for the tunnel magnetoresistance, which exhibits regions of enhanced or negative values—new features resulting from the coupling to Majorana wire. [ABSTRACT FROM AUTHOR]

Light-induced desorption of Rb atoms from a ferrimagnetic Fe 3 O 4 (001) surface was studied using a spin-selective optical method, which provides information on the spin polarization, velocity distribution, and amount of the desorbed atoms. The results showed that the intensity of the desorption of Rb from Fe 3 O 4 (001) induced by ultraviolet (UV) light irradiation was smaller than the detection limit at coverages lower than the threshold coverage at which the desorption rate began to increase. Moreover, the average magnetic quantum number of the desorbed atoms was smaller than that of electrons at the Fermi level of the Fe 3 O 4 (001) surface. These indicate that the light-induced desorption of Rb from an Fe 3 O 4 (001) surface occurs only in the high-coverage region in which the desorbing atoms are not in contact with the Fe 3 O 4 surface, and that the desorption does not involve spin transfer. [ABSTRACT FROM AUTHOR]

Highlights: Single-molecule electrical detection, especially the single-molecule junction setup, enables the precise detection and spatial operability of anchored molecules. The transition among asymmetric characteristics (i.e., molecular chirality, photonic polarization and electronic spin) is proposed as a universal methodology to realize the detection, control and synthesis of chirality. Exploring the origin of symmetry breaking contributes to the development of a general reliable strategy for asymmetric synthesis. Chirality, as the symmetric breaking of molecules, plays an essential role in physical, chemical and especially biological processes, which highlights the accurate distinction among heterochiralities as well as the precise preparation for homochirality. To this end, the well-designed structure-specific recognizer and catalysis reactor are necessitated, respectively. However, each kind of target molecules requires a custom-made chiral partner and the dynamic disorder of spatial-orientation distribution of molecules at the ensemble level leads to an inefficient protocol. In this perspective article, we developed a universal strategy capable of realizing the chirality detection and control by the external symmetry breaking based on the alignment of the molecular frame to external stimuli. Specifically, in combination with the discussion about the relationship among the chirality (molecule), spin (electron) and polarization (photon), i.e., the three natural symmetry breaking, single-molecule junctions were proposed to achieve a single-molecule/event-resolved detection and synthesis. The fixation of the molecular orientation and the CMOS-compatibility provide an efficient interface to achieve the external input of symmetry breaking. This perspective is believed to offer more efficient applications in accurate chirality detection and precise asymmetric synthesis via the close collaboration of chemists, physicists, materials scientists, and engineers. [ABSTRACT FROM AUTHOR]

The role of spin–orbit interaction has been recently reconsidered in high- T c cuprates, stimulated by the recent experimental observations of spin-polarized electronic states. However, due to the complexity of the spin texture reported, the origin of the spin polarization in high- T c cuprates remains unclear. Here, we present the spin- and angle-resolved photoemission spectroscopy (ARPES) data on the facing momentum points that are symmetric with respect to the Γ point, to ensure the intrinsic spin nature related to the initial state. We consistently found the very weak spin polarization only along the nodal direction, with no indication of spin-splitting of the band. Our findings thus call for a revision of the simple application of the spin–orbit interaction, which has been treated within the standard framework of the Rashba interaction in high- T c cuprates. [ABSTRACT FROM AUTHOR]

A possibility of generating a high degree of spin polarization of 13C and 15N nuclei in the cyanide ion, which forms the coordination bond with the metal ion, using parahydrogen is demonstrated for the first time for the new iridium carbene complex as an example. The spin–spin interaction constants in the synthesized complex and the structure of the hydride intermediate are determined by an analysis of the 13С NMR spectra detected using broadband and selective heteronuclear decoupling. The cyanide ion is shown to coordinate to the metal ion by the carbon atom in one of two equatorial positions, and two pyridine molecules are arranged in the axial and equatorial positions. The signal amplification factors for 13С and 15N nuclei of the cyanide anion (5665 and –49 555, respectively) are estimated by NMR spectroscopy of the polarized substrate using the SABRE method from an ultralow magnetic field of 0.5 μT. This amplification corresponds to 15.5% polarization of nitrogen nuclei achieved within several seconds at room temperature. [ABSTRACT FROM AUTHOR]

We study the impact of the QCD critical point (CP) on the spin polarization of Λ -hyperon generated by the thermal vorticity in viscous quark gluon plasma (QGP). The equations of the relativistic causal viscous hydrodynamics have been solved numerically in (3+1) dimensions to evaluate the thermal vorticity. The effects of the CP have been incorporated through the equation of state (EoS) and the scaling behavior of the transport coefficients. We observe a significant suppression of the spin polarization around mid-rapidity region induced by the CP and propose that such changed behaviour of the spin polarization can be used to detect the CP. To the best of our knowledge this is the first study on the effects of critical point on the spin polarization in QCD matter. [ABSTRACT FROM AUTHOR]

Both Ti2FeGe and CoTiFeGe compounds were designed based on density functional theory within GGA and mBJ-GGA approximations. Lattice parameter optimization in ferromagnetic and nonmagnetic phases for XA type structures were done in order to predict the magnetic stable ground state. The calculated total energy indicates that the most stable phase of XA type ordering is ferromagnetic state. The band structure and density of states for XA type ordering for the studied alloys exhibit half-metallic nature using GGA and mBJ-GGA approaches that is a precursor for high spin polarization in those alloys. Except for Ti2FeGe alloy, which exhibits metallic character when we used mBJ-GGA method. The calculated energy bands indicate that Ti2FeGe (CoTiFeGe) is an indirect band gap and the value of gap is 0.606 eV (0.490 eV) using GGA scheme and it is 0.00 eV (0.982 eV) by mBJ-GGA method. The elastic properties, such as stability, hardness, stiffness, ductility and brittleness were explored and determined by simulated elastic constants. The anisotropy of the stable compounds Ti2FeGe and CoTiFeGe have values in 3.79 and 2:73, respectively. Also, the Ti2FeGe and CoTiFeGe compounds follow the necessary Slater–Pauling rule conditions Mtot = NV-18 and Mtot = NV-24 for half-metallicity and they have a total magnetic moment of 2 µB and 1 µB, respectively. Their optical properties have confirmed semiconducting behavior and their main optical response occurs in the infrared (IR) and visible ranges and the very low loss in the same region, along with existence absorption, make them as suitable for optoelectronic applications for novel infrared (IR) detector devices. The substitution by Co led to a slight blue shift of the optical peaks. [ABSTRACT FROM AUTHOR]

Using the first-principles calculations based on density functional theory (DFT) within the generalized gradient approximation (GGA), Ti2RuAl full-Heusler compound is studied. The electronic structure, magnetic, and optical properties of Ti2-based full Heusler compound Ti2RuAl are calculated and analyzed using the Wien2k package. The CuHg2Ti-type structure is found to be more favorable than the AlCu2Mn-type structure for this compound. The Ti2RuAl Heusler compound exhibits a ferrimagnetic half-metallic behavior with the total magnetic moment of 1 µB at the equilibrium lattice constant 6.24 Å. The total magnetic moment of Ti2RuAl is in agreement with the Slater-Pauling rule mtot = ztot–18 and hence has integral magnetic moments which is due to 100% spin polarization at Fermi energy. Ti2RuAl has an energy gap in the spin-down channel of 0.229 eV. This compound keeps a 100% of spin polarization for lattice constant change in the range of 5.8–6.5 Å. The Curie temperature of Ti2RuAl is estimated to be 451 K using the mean field approximation (MFA). In addition, optical properties like dielectric function, reflectivity, energy loss function, absorption coefficient, and optical conductivity are calculated. [ABSTRACT FROM AUTHOR]

Carbon-based single-atom catalysts (SACs) for electrochemical nitrogen reduction reaction (NRR) have received increasing attention due to their sustainable, efficient, and green advantages. However, at present, the research on carbon nanotubes (CNTs)-based NRR catalysts is very limited. In this paper, using FeN3@(n, 0) CNTs (n = 3 ~ 10) as the representative catalysts, we demonstrate that the CNT curvatures will affect the spin polarization of the catalytic active centers, the activation of the adsorbed N2 molecules and the Gibbs free energy barriers for the formation of the critical intermediates in the NRR processes, thus changing the catalytic performance of CNT-based catalysts. Zigzag (8, 0) CNT was taken as the optimal substrate, and twenty transition metal atoms (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Tc, Ru, Rh, Pd, W, Re, Ir, and Pt) were embedded into (8, 0) CNT via N3 group to construct the NRR catalysts. Their electrocatalytic performance for NRR were examined using DFT calculations, and TcN3@(8, 0) CNT was screened out as the best candidate with a low onset potential of − 0.53 V via the distal mechanism, which is superior to the molecules- or graphene-support Tc catalysts. Further electronic properties analysis shows that the high NRR performance of TcN3@(8, 0) CNT originates from the strong d-2π* interaction between the N2 molecule and Tc atom. TcN3@(8, 0) CNT also exhibits higher selectivity for NRR than the competing hydrogen evolution reaction (HER) process. The present work not only provides a promising catalyst for NRR, but also open up opportunities for further exploring of low-dimensional carbon-based high efficiency electrochemical NRR catalysts. [ABSTRACT FROM AUTHOR]

Here, we report the experimental investigations on magnetic (spin polarization and exchange bias) and transport (spin-flip and spin-flop) properties of Co2FeSi Heusler compound at cryo temperature and high magnetic field. The spin cluster characteristic of the material is revealed by the M[T] curve of the ZFC, FC, and FW cycles. This can exhibit spin polarization behavior of anti-ferromagnetism (AFM) at 30–70 K. Furthermore, at a critical field of 0.2 T, AFM transforms into ferromagnetic (FM) and on further increasing the magnetic field, the spin polarization region becomes linear due to perseverance of FM behavior. The isothermal magnetization [M(H)] are also evaluated at different temperatures and AFM to FM transition has been observed at various applied magnetic fields. These magnetic measurements are used to determine exchange bias [EB] parameters such as HE, HC, and Mr both at low and room temperature. The resistivity [ρ(T)] has been measured at 0 and 5 T field, which explain the increasing trend of metallic nature at cooling cycle and also provides a clear evidence of magnonic, phononic resistivity and spin-flip scattering. [ABSTRACT FROM AUTHOR]

In this work, the electronic and magnetic features of the Sc2MnSi bulk, surfaces, and the interface with the semiconductor CdTe (111) were thoroughly researched using the first-principles calculations. The Sc2MnSi alloy with equilibrium lattice constant of 6.34 Å shows half-metallic (HM) property. This alloy exhibits an energy gap and a HM gap of 0.54 and 0.12 eV, respectively. The density of states results confirm the existence of the half-metallicity property for the Sc2MnSi component at SiSc(2)-(001), Sc(2)-, and Si-(111) surfaces while this property is not revealed at Sc(1)-, Mn-terminated (111), Sc(1)Mn-terminated (001), and Sc2MnSi (110) surfaces for the same component. In addition, in the case of Sc2MnSi/CdTe interface, it is noted that Cd-Si connection does not reveal the half-metallicity feature, while the Si-Te shape exhibits a 100% spin polarization, thus preserving the half-metallicity. Furthermore, the Si-Te shape is more stable than the others, according to the interfacial adhesion energy. [ABSTRACT FROM AUTHOR]

The antichiral edge states induced by the modified Haldane model have been predicted in the previous studies. In this study, other types of antichiral edge states are proposed by applying the side potentials composed of a potential field, staggered electric field, and exchange field along the boundaries of zigzag honeycomb nanoribbons (zHNRs). Their corresponding transport properties are investigated. The results show that the side potentials can lift the spin degeneracy of the edge modes, inducing five types of antichiral edge states. By calculating the spin-dependent energies in K' and K valleys of the edge modes, an interpretation for generating antichiral edge states is proposed. In addition, the spin/charge switcher in the three-terminal device consisting of zHNRs is developed based on the induced edge states. We believe that these results can be used in the design of future spintronic devices. In the modified Haldane model, antichiral edge states appear at the boundary of zigzag honeycomb nanoribbons. These flow oppositely at the boundary and the center of the ribbon. In this work, the authors show how to decorate the system boundary to control the edge modes' current and spin polarization. They show how to form a three-terminal system where an unpolarized current splits into two fully spin-polarized ones. [ABSTRACT FROM AUTHOR]

The injection of a pure spin current into a conducting helimagnet is investigated. The characteristic decay lengths for the spin current injected into the helimagnet are determined, and their physical meaning is described. It is shown that instead of the spin diffusion length, helimagnets are characterized by the decay length that is always smaller than the spin diffusion length, the difference in these lengths being determined by the ratio of the helimagnet spiral period to the spin diffusion length. We predict the existence of the "effect of the chiral polarization of a pure spin current," i.e., the emergence of the spin current with longitudinal (transverse) polarization, which depends on the spiral chirality, upon the injection of a pure spin current with the transverse (longitudinal) polarization relative to the spiral axis. [ABSTRACT FROM AUTHOR]

The half-metallic and pressure-induced elastic properties of PdVSi, PdVGe, PdVSn, and PdVSb were investigated. First, FM phases were obtained energetically as the most stable. The semiconducting characters seemed in spin-down states. The band gaps were calculated as 0.807 eV, 0.676 eV, 0.481 eV and 0.370 for PdVSi, PdVGe, PdVSn, and PdVSb, respectively. Since the spin polarization value of PdVSb alloy is less than 100% in GGA method, it is nearly half-metallic ferromagnetic, while other alloys are true half-metallic ferromagnetic. However, in HSE method, the forbidden and half-metallic band gaps were also calculated for PdVSb alloy as 0.375 eV and 0.134 eV, respectively. HSE method has a direct effect on the band gap values. PdVSi, PdVGe, and PdVSn, alloys have 1.00 μB/f.u. total magnetic moments, while PdVSb alloy has 2.00 μB/f.u. total magnetic moment. According to elastic results, all alloys are elastically stable and ductile materials. Debye temperatures were obtained as 371.53 K, 317.71 K, 311.78 K, and 263.13 K at 0 GPa pressure. PdVSi, PdVGe, PdVSn, and PdVSb alloys have been obtained as very remarkable materials with their structural, electronic, magnetic and pressure-induced elastic properties. [ABSTRACT FROM AUTHOR]

The magnetic proximity effect is significant for atomically thin layers of two-dimensional materials. In this paper, we study the mechanisms of photogeneration spin-polarized carriers in graphene on a magnetic insulator. The magnetic proximity effect and lowered symmetry at the interface enhance the spin response of graphene in the alternating electric field of the incident light. The first leads to spin splitting of the linear spectrum of Dirac electrons. The second increases the role of the spin-orbit interaction. The main mechanisms of photogenerated spin polarization have been considered, including spin flip intersubband and interband transitions, and their contribution to the absorption coefficient of graphene. [ABSTRACT FROM AUTHOR]

The transport properties, containing the spin polarization and transmission probability, theoretically have been investigated on the exposure of an exterior magnetic field for single-layer phosphorene superlattice using the transfer matrix method. We illustrated that by controlling incoming energy, external magnetic field, or through varying the distance between two barriers, the number of barriers, and its thickness, spin transmission probabilities for phosphorene superlattice can be adjusted. The results have shown that the most transmission probability in the attendance of an exterior magnetic field happened for 5 barriers, as well as the transmission probability reduces by raising the width of the separation in the barriers for a specific magnetic field. As well, an electron beam whose spin polarization is zero can be converted into an ideal efficiency spin polarization by controlling the external magnetic field, which has a substantial role in qubit circuits. [ABSTRACT FROM AUTHOR]

Electron paramagnetic resonance (EPR) spectra of synthetic diamond microcrystals with NV(‒)‑centers have been studied. It is shown that under the conditions of irradiation of the material with the light of a xenon lamp at low temperatures ~100 K, the intensities of the EPR signals corresponding to the "forbidden" (Δms = 2) and low field allowed (Δms = 1) transitions are amplified several times, while the EPR signals from paramagnetic nitrogen and impurity nickel in the charge state –1 practically do not change. This is due to a change in the population of levels of the ground triplet state of the NV(–)-center and the optical polarization of spins in the state ms = 0 of the triplet level. [ABSTRACT FROM AUTHOR]

The results of the theoretical investigation of the local structural changes and adsorption characteristics of the graphene (GP) surface in the presence of a vacancy + Auads adatom complex are presented. Based on the density functional theory (DFT), the adsorption properties of Auads at the surface of GP supercells containing 50 carbon atoms with vacancies ) are calculated. The most stable configuration of supercells with a vacancy + Auads adatom complex is determined. The effect that an Auads adatom has on the band structure and local magnetic moment in is calculated. The data are analyzed based on the equilibrium atomic configuration , local density of electronic states, and spin polarization. The calculations are made using the exchange-correlation functional in a local electron-spin density approximation (LSDA). [ABSTRACT FROM AUTHOR]

A comparative analysis of experiments devoted to studying, in the fission process, () angular correlations, on one hand, and () and () angular correlations, on the other hand, is performed on the basis of the model proposed earlier for describing muon conversion in fragments originating from the prompt fission of U nuclei that is induced by negatively charged muons. It is shown that each of these experiments may provide information that does not depend on the results of the other experiments and which is complementary to them. Historically, the situation resembles the Einstein–Podolsky–Rosen (EPR) paradox. An experimental verification of the theoretical relation between the alignment and polarization of fragment spins in the CORA experiment is of crucial importance. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance has experienced great advances in developing and translating hyperpolarization methods into procedures for fundamental and clinical studies. Here, we propose the use of a wide-bore NMR for large-scale (volume- and concentration-wise) production of hyperpolarized media using parahydrogen-induced polarization. We discuss the benefits of radio frequency-induced parahydrogen spin order transfer, we show that 100% polarization is theoretically expected for homogeneous B0 and B1 magnetic fields for a three-spin system. Moreover, we estimated that the efficiency of spin order transfer is not significantly reduced when the B1 inhomogeneity is below ± 5%; recommendations for the sample size and RF coils are also given. With the latest breakthrough in the high-yield synthesis of 1-13C-vinyl pyruvate and its deuterated isotopologues, the high-field PHIP-SAH will gain increased attention. Some remaining challenges will be addressed shortly. [ABSTRACT FROM AUTHOR]

The spin-photo current in single layer stanene and germanene under a linearly polarized light is theoretically investigated based on the tight-binding Hamiltonian combined with the nonequilibrium Green's function at room temperature. The results show that by considering the simultaneous effect of the linear illumination and a vertical external electric field without any magnetic exchange element, pure spin-photo current without charge current is generated in two-dimensional lattices with a large intrinsic spin–orbit coupling. The necessity of enhanced spin life-time for detection of spin polarization can be explained by spin-valley locking concept. Spin-valley locking arises in buckled two-dimensional materials as a result of the large spin–orbit coupling and electric-field reversible valley spin polarization. Equal absorption of the linearly illumination at both valleys with different spin polarization, leads to pure spin-photo current injection. In addition, an acceptable photoresponsivity has been reported in a broad range of photon energy. The numerical results indicate high quantum efficiency with a maximum of nearly 83% and 50% for stanene and germanene, respectively. This work may pave theoretical reference toward design of new spin-optoelectronic devices based on satanene and germanene junctions with high performance. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance has experienced great advances in developing and translating hyperpolarization methods into procedures for fundamental and clinical studies. Here, we propose the use of a wide-bore NMR for large-scale (volume- and concentration-wise) production of hyperpolarized media using parahydrogen-induced polarization. We discuss the benefits of radio frequency-induced parahydrogen spin order transfer, we show that 100% polarization is theoretically expected for homogeneous B0 and B1 magnetic fields for a three-spin system. Moreover, we estimated that the efficiency of spin order transfer is not significantly reduced when the B1 inhomogeneity is below ± 5%; recommendations for the sample size and RF coils are also given. With the latest breakthrough in the high-yield synthesis of 1-13C-vinyl pyruvate and its deuterated isotopologues, the high-field PHIP-SAH will gain increased attention. Some remaining challenges will be addressed shortly. [ABSTRACT FROM AUTHOR]

The structural parameters, exchange splittings, half-metallic property, electronic features and magnetic performances of Ba1−xCrxS materials were determined by utilizing the computational methods of density functional theory. The localized magnetic spins in the Ba1−xCrxS result from the effect of the hole carriers caused by the d shells of Cr atom, hybridizing with p levels of S atom. The ferromagnetism is mostly endorsed by the exchange splitting owing to its large contribution than that of the crystal field. The Ba1−xCrxS (x = 0.25), Ba1−xCrxS (x = 0.5)and Ba1−xCrxS (x = 0.75) materials have half-metallic characteristic with ferromagnetic state, where their electronic structures demonstrate spin polarizations of 100% with half-gaps of 0.815, 0.912 and 0.72 eV, respectively. Therefore, Ba1−xCrxS systems have better magneto-electronic performances, making them appropriate half-metallic materials for spin-injection applications for spintronics. [ABSTRACT FROM AUTHOR]

In the present investigation, first principle calculation on half Heusler (HH), FeNbSb compound was performed using the Wien2K code. Structural analysis was performed using volume optimization curves by Birch Murnaghan equation of states. Three different (viz. α, β and γ) crystallographic phases of FeNbSb compound were investigated to found out the stable structural phase. It was found that α phase of the compound is more stable as compared to the rest phases of FeNbSb alloy. Stable α, phase of FeNbSb compound, was adopted to further investigate the spin polarized ground state physical properties. Spin polarized density of states (DOS) and band structure (BS) calculations show the nonmagnetic semiconductor behavior of the compound having small band gap of ~ 0.6 eV. DOS profile shows that major contribution is due to Fe-3d, Nb-4d and Sb-5p orbitals. Dielectric spectra also indicate the semiconductor behavior of the compound with various intense peaks. All other calculated optical parameters are in line with our DOS and BS calculations. Optical absorption and conductivity were found to be maximum in the visible region of the spectrum. Overall, compound would be the potential candidate for its applications in electronic and optical devices. [ABSTRACT FROM AUTHOR]

Lanthanide-binding proteins have been examined for the specific lanthanide physical properties and the biological activities of peptide scaffolds. The chirality-induced spin selectivity (CISS) of helical peptide structures is a crucial aspect of spin polarization. Combining CISS-caused spin polarization with a paramagnetic lanthanide ion can yield protein-based memristance and protein sensing. In this study, coherent spin transport in a lanthanide-binding protein was examined based on first-principles calculations to discuss spin polarization in lanthanide-binding proteins. Among lanthanides, lanthanum-binding proteins, which exhibit no paramagnetic spin state, exhibit spin polarization in peptide structures. [ABSTRACT FROM AUTHOR]

The paper presents a novel composite material based on nanoporous AB-stacked bilayer graphene. The influence of the dopant atom on the electronic properties of the heterostructure and its position in the pore is investigated herein. The proposed effect is considered on composite materials doped with calcium and manganese atoms in order to correctly evaluate the influence of the valence shell filling type without the local field effect caused by the structural properties of an AB-stacked bilayer graphene. [ABSTRACT FROM AUTHOR]

The paper presents research results of the thermal effect on the structure, phase composition, and morphology of natural magnesite (MgCO3) from the Savinsky deposit (Irkutsk region) used as a raw material. Two types of thermal treatment are applied to test specimens, namely: isothermal exposure at 1173 K and heating and melting in thermal plasma at a bulk temperature of 6500 K. According to the qualitative phase analysis, major phases include MgCO3 and MgO with hexagonal and cubic crystal systems. Complete information is obtained for the lattice structure both in the initial state and after Rietveld refinement of structural parameters. The high-throughput framework Aflow is used to evaluate the phase stability of the crystal lattices using the convex hull construction. The stability plot of MgCO3 and energy color matching are suggested with regard to spin polarization. [ABSTRACT FROM AUTHOR]

In our previous works [J. Phys. Chem. Solids 163 (2022) 110600], the CrLaCoAl alloy had been predicted to be half-metallic ferrimagnet with high Curie temperature, and it met the dynamic, mechanical and thermal stabilities. Furthermore, a smaller convex hull indicated that it was likely to be prepared in experiment. However, the half-metallicity of CrLaCoAl alloy is possible to be destroyed by defect. Therefore, it is necessary to study the stability, electronic and magnetic properties of defective CrLaCoAl. Results show that the formation energies of the Cr–La, Co–Al swap and Al(Cr), Co(La) antisite are negative, indicating that they are likely to be formed in the process of crystal growth. Among them, the formation energy of the Al(Cr) antisite is the lowest in defects, and the spin polarization is as high as 93.72%. In addition, the spin polarization of all antisites is over 60% except for the Cr(Al), La(Cr) and La(Al) antisite. High spin polarization in defect is favorable in spintronic application. [ABSTRACT FROM AUTHOR]

The magnetic properties of Co-doped CdS has been investigated by ab initio calculations using the GGA + U approximation. The study reveals the ferromagnetic ordering of Co-doped CdS at lower concentrations of Co, whereas, at higher concentrations, the antiferromagnetic interactions dominate. The electronic structures reveal the half metallic character signifying 100% spin polarization. Significant hybridization between d states of Co and p states of S is observed in the density of states indicates the Co-induced ferromagnetism in CdS. The lower formation energy promises superior stability and shows that Co-doped CdS can be easily fabricated experimentally. [ABSTRACT FROM AUTHOR]

The crystal structure and magnetic properties of Fe4BO7 and Mn4BO7 tetraborates have been studied within DFT-GGA. The tetraborates can be found in several possible structural modifications. Three of them, namely, (α-ZnB4O7), (β-ZnB4O7 structure type), and (γ-NiB4O7 structure type) have been considered here. The possible magnetic orderings in three structure types are described within group-theoretical analysis. The following DFT calculations allow finding the lowest energy magnetic structure for Fe4BO7 and Mn4BO7 in three structure types. The total energies of tetraborates in three structure types have been compared with and without taking into account the spin polarization. It has been found that Mn4BO7 and Fe4BO7 in the non-spin-polarized case have the α-ZnB4O7 and γ-NiB4O7 structure types as the lowest energy structure, respectively. However, when the magnetic structure is taken into account, the antiferromagnetic α-ZnB4O7 phase becomes the ground state for both tetraborates. The pressure dependence of the enthalpy of Fe4BO7 and Mn4BO7 tetraborates has been studied. It has been found that the applied pressure results in the appearance of the β-ZnB4O7 structure type as the lowest energy structure under pressure. [ABSTRACT FROM AUTHOR]

A possibility of generating spin polarization of 19F nuclei in the counterions that form no covalent bond with the metal center is shown for the first time for new iridium complexes synthesized by reversible binding with the substrate (pyridine) and parahydrogen. This makes it possible to observe the integral polarization of 19F nuclei in weakly coordinated tetrafluoroborate and hexafluorophosphate anions. The optimum parameters of the magnetic field strength for the maximum amplification of the 19F signal in two fluorine-containing anions are determined from the dependences of the signal intensity in the NMR spectra on the magnetic field strength for two synthesized iridium complexes. [ABSTRACT FROM AUTHOR]

The ab initio investigations of Mx (M = Y, Zr, Nb)–Sc1-x–Sn diluted ternary alloys were calculated for x = 0.25, 0.125, and 0.0625 ratios in GGA and GGA + mBJ methods. Half-metallic band gaps were observed in the spin-up electron states. Only the spin-up electrons of the Nb0.25Sc0.75Sn alloy cut the Fermi energy level and reduced the spin polarization amount to 75.24%. Band gap values were also obtained in both GGA and GGA + mBJ methods. When the GGA + mBJ method was used, an increase was observed in the half-metallic characters of the alloys. Therefore, all the alloys were obtained as true half-metallic ferromagnetic materials. Total magnetic moment values were obtained as 4.00 μB/f.u. in all ratios of Y–Sc–Sn alloys. Since Y and Sc are in the same period, this result is expected for half-metallic alloys. While the total magnetic moment was 3.00 μB/f.u. for the 0.25 ratio in the Zr–Sc–Sn alloy, it was obtained as 3.50 μB/f.u. and 3.75 μB/f.u. for the 0.125 and 0.0625 ratios, respectively. While the total magnetic moment of the Nb0.25Sc0.75Sn alloy was obtained as 1.923 μB/f.u., the magnetic moment values increased to 3.00 μB/f.u. and 3.50 μB/f.u., respectively, when the amount of Sc increased. In short, considering both their electronic and magnetic properties, Mx (M = Y, Zr, Nb)-Sc1-x-Sn ternary alloys are quite suitable for spintronic applications. [ABSTRACT FROM AUTHOR]