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ABO 3 perovskites oxides show fascinating functional properties, including ferroelectricity, magnetism, metal-to-insulator transition, half metallicity, polar metallic phase, etc. In particular, rare earth nickelates and alkaline earth nickelates within the orthorhombic crystal structures show an insulator–metal transition (IMT) and half-metallic (HM) nature respectively. Here, we report a series of ferromagnetic polar half metals by constructing LnNiO 3 /CaNiO 3 short period 1/1 superlattices (SLs) with Ln = La, Nd, Gd, Dy, Tm, and Lu within an orthorhombic phase. The polar distortion is induced by a hybrid-improper ferroelectric mechanism i.e., by constructing Ln/Ca layer-ordering. The system shows a ferromagnetic Ni-Ni interaction, whereas Ni-3 d 's are interacting antiferromagnetically with O-2 p. We explain that the origin of observed half metallicity and ferromagnetism is due to strong hybridization between Ni-3 d and O-2 p near the Fermi level and double exchange mechanism, respectively. • Ferromagnetic polar half-metals within LnNiO 3 /CaNiO 3 • Large spin polarization is expected. • Hole mediated double exchange mechanism drives the ferromagnetic ordering. • The systems exhibit polar nature through hybrid improper ferroelectric mechanism. • These systems are metallic due to strong hybridization between Ni-3 d and O-2 p. [ABSTRACT FROM AUTHOR]

• The effect of 3d TM dopants (12.5% doping concentration) in BiCoO 3 having C-type AFM arrangement has been studied using first principle calculation to study the structural, electronic and magnetic properties. • The defect states are introduced due to presence of 3d TM dopants in BCO. • The PDOS reveal that V, Ni and Zn doped BCO exhibit half metallic characteristics. • The net magnetization was found to arise due to TM doping at Co site which may be attributed to the uncompensated Co spins and is mainly localized on the TM dopant. • SSP model was used to explain the net magnetization in the system due to 3d TM dopants in BCO system. • Ti doped BCO system found to be most stable due to lowest formation energy as compared to other 3d TM doped BCO system. In this paper, the influence of 3d transition metal (TM) dopants in BiCoO 3 (BCO) having C-type antiferromagnetism has been studied using first principles calculation. The value of c/a ratio is found to improve for Sc, V, Mn, Fe, Ni, Cu and Zn doping in BCO which indicates an increase in the tetragonality ratio upon introduction of these dopants in BCO. The formation energy calculations pointed out that it is easier to incorporate the TM atoms having number of d atoms lesser than that of Co (d < 7) in BCO. The electronic, and magnetic properties were studied and it was found that the electron/hole traps are introduced due to the presence of 3d TM dopant in BCO. The partial density of states reveal that V, Ni and Zn doped BCO exhibit half metallic characteristics with a lower band gap value among the other TM doped BCO systems. It was interesting to note that the presence of states in both spins at Fermi level due to Cu doping leads to a transition of BCO towards metallic behaviour in contrast to pure BCO having a clear band gap of 1.77 eV. The net magnetization was found to arise due to TM doping at Co site which may be attributed to the uncompensated Co spins and is mainly localized on the TM dopant. Successive spin polarization model (SSP model) was used to explain the net magnetization in the system due to 3d TM dopants in BCO system. The electron localization function plots also reveal that for d < 5 the electrons are localised near the TM metal ions and for d > 5 the localization impacts the near neighbouring Co ions. From this study, it is suggested that the magnetic and electronic properties of BCO system, can be tuned by 3d TM doping which has vast potential in photovoltaic and magneto-electric applications. [ABSTRACT FROM AUTHOR]

The double perovskites have outstanding properties for spintronic devices as they are stable, non-toxic, and accomplish the spin polarization. This article studies the function of 5d-electrons of Ta, W, Re and Os to regulate the magnetic properties of Sr 2 CrXO 6. The tolerance factors and formation energies confirm the stability of the structures and the thermodynamics. The half-metallic ferromagnetic nature is found by analyzing the density of states and band structures described by the double exchange model, exchange energy, and exchange constants. According calculations, ferromagnetism is induced by the electron spin due to hybridization process, magnetic moments, exchange energies, and crystal field energy. The thermoelectric applications are further explored by computing and discussing the thermal and electrical conductivities, and Seebeck coefficients. The power factor has also been elaborated for the performance of studied DPs. • Ferromagnetism at high temperature, and spintronic applications. • Spin of electrons operates the devices with multifuctional properties. • Role of 5d electrons and exchange of energies. • Half metallic ferromagnetism and complete spin polarization. • Ultralow low values of thermal conductivity. [ABSTRACT FROM AUTHOR]

We have grown thin films of Co 2 TiSi (CTS) Heusler alloy on n-type Si (100) at different substrate temperatures by electron beam evaporator under a high vacuum. The structural, magnetic, and electric characterizations were carried out and found a strong correlation between the properties and the growth temperatures of the samples. The crystallinity and magnetic moment both were significantly improved with increasing growth temperatures from room temperature to 400 °C. The saturation magnetization of 1.85 µ B at 10 K is close to the theoretical Slater–Pauling value. A large value of spin wave stiffness constant (D = 7.2 meV- nm2) of CTS film manifests the robustness of magnetization. The temperature-dependent longitudinal resistivity demonstrated different scattering phenomenon like weak localization, electron-magnon, electron-election, and electron-phonon interactions. A decrease in residual resistivity (109–49 µΩ-cm) and an increase in residual resistivity ratio (1.2–1.39) indicate an enhancement of crystallinity and structural order of CTS films. By first principle study using DFT calculation we have analyzed the effect of atomic site disorder on electronic properties of both bulk and thin film (220) surface form of CTS Heusler alloy. It has been noticed that the ordered bulk structure shows perfect half-metallic nature but for thin film the spin polarization and moment both are deviated from identical value. The spin polarization and magnetic moment both are reduced a lot by introducing atomic site disorder in L2 1 ordered structure. • Co 2 TiSi films with different subtrate temperatures are grown by electron beam evaporator. • Studies the impact of growth substrate temperatures on structural and magnetic properties Co 2 TiSi film. • Resistivity study suggests the presence of different scattering phenomena. • Effect of atomic site disorder on magnetic moment and spin polarization of bulk and thin film by DFT calculations. [ABSTRACT FROM AUTHOR]

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

In this study, we presented a novel reflective spin-exchange relaxation-free (SERF) atomic magnetometer that enhances the magnetometer's spin polarization and spin polarization spatial uniformity, thereby improving its performance and stability. We derived a comprehensive spin polarization model and conducted simulations to demonstrate the positive impact of the reflective configuration on spin polarization and its spatial uniformity. A diminishing marginal effect of increasing the reflection ratio as the incident optical power increases was observed. Experimental designs were employed to obtain spin polarization information, validating the accuracy and effectiveness of the simulated conclusions. Utilizing the core parameter of long-term sensitivity as the primary criterion for selecting the transmission-to-reflection ratio in the reflective configuration. The experiments yielded a minimum long-term sensitivity of 14. 9 ± 5. 9 fT/Hz 1/2 (@31.5 Hz) and an optimal single-shot magnetic field measurement sensitivity of 10.0 fT/Hz 1/2 (@31.5 Hz). These results supported the viewpoint of selecting intermediate levels of transmission-to-reflection ratio and incident light power. Moreover, the experiments verified that the reflective magnetometer outperformed the conventional magnetometer. Further research on such reflective magnetometers will contribute to advancing magnetometer system performance and stability, with significant implications for future applications in bio-magnetic measurements. [Display omitted] • A novel reflective atomic magnetometer was presented. • Improve the magnetometer's spin polarization and its spatial uniformity. • The minimum long-term sensitivity was 15.3 ± 5.5 fT/Hz1/2 (@31.5 Hz). • An optimal single-shot magnetic field sensitivity was 10.0 fT/Hz1/2 (@31.5 Hz). • Determine the viewpoint of selecting intermediate transmission-to-reflection ratio. [ABSTRACT FROM AUTHOR]

The effective mass of holes (m ∗) in GaAs quantum wells is investigated as a function of spin polarization, temperature, and carrier density using the Hartree–Fock approximation. The results reveal m ∗ initially decreases at low carrier densities before increasing with density. Additionally, as the interaction parameter increases, m ∗ decreases rapidly. Especially, as the temperature rises to 200 K, m ∗ asymptotically approaches a value of 0.45 m 0 , where m 0 is the electron mass. These findings provide insights into the influence of Coulomb interaction and exchange energy on the effective mass of semiconductors across a wide range of temperatures, spin polarizations, and densities. • Spin, temperature, and carrier density dependence of hole effective mass in quantum well is analyzed. • Majority mass increases with spin polarization while minority mass decreases. • Majority mass has a clear minimum at low every temperature an at low carrier density below 2 × 1010 cm−2. • The results are consistent with experimental results. [ABSTRACT FROM AUTHOR]

We report the structural stability and half-metallicity of the half-Heusler alloy CoMnSe via the density functional theory (DFT). The γ -phase ferromagnetic of CoMnSe is more energetically stable than other phases. The electronic and magnetic properties show that the CoMnSe is a false half-metal ferromagnetic with 98.10% spin polarization and a total magnetic moment of 4 μ B . This value is in good agreement with the Slater-Pauling rule and available data using the GGA method, whereas the GGA+U method shows it is a ferrimagnetic metal with 95.73% spin polarization, and the total magnetic moment is 4.01 μ B. The effects of Bulk strain and axial strain demonstrate that the relative change of total magnetic moment M t o t and spin polarization P of CoMnSe is almost negligible, indicating that the half-metallicity is strong against Bulk strain and axial strain. Using Monte Carlo simulations, a transition ferromagnetic-paramagnetic response is also studied. • CoMnSe alloy is mechanically and thermodynamically stable. • CoMnSe does not undergo martensitic transformation. • CoMnSe is found to be falsely half-metallic using GGA, while it is metallic using GGA+U. • The high spin polarization and Curie temperature make CoMnSe suitable for spintronic. [ABSTRACT FROM AUTHOR]

• The intrinsic room-temperature ferromagnetic behavior can be realized and regulated by external strain. • The structural deformation not only regulates the spin polarization feature but also leads to an electronic reconfiguration. • Our findings provide a new insight into designing 2D spintronic devices by strain engineering in hexagonal MIn 2 S 4 monolayers. The electronic occupation at 3d transition metal and crystal symmetry play a critical role in realizing spin polarization, but the weak spin exchange interaction makes it difficult to obtain room-temperature ferromagnetism, especially in two-dimensional (2D) materials. Different from traditional bulk phase with semiconducting feature, the free-standing hexagonal MIn 2 S 4 (M = Fe, Co, Ni, Mn) monolayers are proposed to discuss the strain-dependent magnetic behavior, in which the 3d-orbital hybridization and charge transfer can be regulated by structural deformation to enforce their spin exchange interaction, finally leading to a room-temperature 2D magnetic characteristic. The calculations disclose that the structural deformation not only regulates the spin polarization feature but also leads to an electronic reconfiguration. Our findings provide a new insight into designing 2D spintronic devices by strain engineering in hexagonal MIn 2 S 4 monolayers. [ABSTRACT FROM AUTHOR]

A new theoretical concept of an electrically controllable single-electron spin filter (polarizator) based on the exchange interaction in the system of interacting quantum dots or impurity atoms is proposed. The sign of the spin polarization of the current flowing through the device can be effectively controlled in two ways (i) by changing the applied bias and (ii) by tuning the tunnel coupling via an external gate. The minimal realization involves three bound state levels coupled to the contact leads. One of these levels is occupied by a single electron with a certain spin and the two-electron occupation is prohibited by a strong on-site Coulomb repulsion. Interestingly, while the spin polarization of this state is fixed, the sign of the single-electron current spin polarization flowing between the contacts through two consistent bound state levels can be switched. • A new theoretical concept of an electrically controllable single-electron spin filter is proposed. • The presence of both exchange interaction and on-site Coulomb repulsion is important. • Spin-filtering can be organized by changing the applied bias or by tuning the tunnel coupling via an external gate. • The considered phenomena are sensitive to electron correlations giving an experimental access to the many-body phenomena. • The obtained results open the possibility for precise control of tunneling current spin polarization. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electronic and magnetic properties of pristine and defected sheets before and after Sc metal decoration are investigated. • The E g values are reduced in the order of pristine(2.01 eV) > 55-77 (1.90 eV) > 5–8-5(1.90 eV) > 4-55-7777(0.58 eV). • The Sc-1 metal decoration produces one unpaired electron to the complex which transforms it to the magnetic state. • The highest spin polarization of P = 4.15 in Pristine_A and P = 3.41 in the 4-55-7777_I complex is obtained. To scrutinize the electronic and magnetic properties of fluorinated pristine, stone wales, di-vacancy, and two stone wales defected graphene sheets by scandium (Sc) metal decoration, the density functional theory is used. The obtained maximum binding and interaction energy values confirm that the two Sc metals decorated on the direct top and bottom of pentagonal rings of the two stone wales graphene sheet have stronger interactions than others. To validate the interactions, natural population analysis and electron density difference map are performed, revealing that Sc metal is the electron donor in all complexes. After the formation of defects in the pristine sheet, energy gap values are reduced in the defected sheets. The density of states infers the shift in the fermi level of all complexes after defect formation and metal decoration. The ultraviolet–visible spectral analysis exposes the highest absorption peaks of all bare sheets at the UV region and after Sc metal decoration, the peaks get red shifted. The results show that Sc metal decorated on two stone wales graphene sheet interacts better with Sc metals than other complexes. The decoration of single Sc metal in all four bare sheets transforms the sheet from a non-magnetic to a magnetic state but when two Sc metals are decorated it became non-magnetic. The highest degree of spin polarization, P = 4.15 is obtained while decorating a single Sc metal on the hexagonal ring of the pristine sheet. The outcome of this work suggests that Sc metal decoration on pristine and defected graphene sheets has great potential to improve the electronic and magnetic properties of graphene for designing spintronic and data storage devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel method for simultaneous measurement of spin polarizability of Rb atoms and 21Ne atoms in the spin-exchange relaxation-free (SERF) co-magnetometer. • The method is based on the frequency response model of K-Rb-21Ne spin strongly coupled ensemble. • Measurements have little influence on the atomic ensemble compared with the traditional method. • The method is more accurate, stabilized and faster than previous methods. • In the presence of interference input rotation and magnetic fields, this method is more suitable for measuring the spin polarizability of atomic ensemble. Accurate and fast measurement of the spin polarizability of alkali-metal and noble-gas atoms in co-magnetometer is essential to improve the sensitivity of ultra-sensitive inertial measurements. We establish a frequency response model of K-Rb-21Ne spin strongly coupled ensembles, based on this we present a method for simultaneously measuring the spin polarization of 21Ne and Rb atoms. By applying magnetic field in y -direction oscillating at a fixed frequency, the z -axis main magnetic field value is changed linearly at the same time, the polarizability of Rb and 21Ne spins can be simultaneously obtained. The experimental results were highly consistent with analytical results. By applying a gradient magnetic field to amplify the effect of atomics depolarization, the self-compensating magnetic field points and atomic ensemble polarizability were measured three times continuously using our method and another method. The results proved that this method has fast measurement speed, high accuracy, and low influence on spin polarisation. [ABSTRACT FROM AUTHOR]

The compressibility was calculated of electrons as a function of external magnetic, temperature and carrier density in the parabolic lateral barrier quantum wires (QWRs). The compressibility found by using Seitz's theorem in which electron self-energy is calculated within the random-phase approximation. All results for GaAs QWRs show that a large difference between the compressibility in low- and high-temperature region at external magnetic fields. These results can help clarify how the Coulomb interaction and exchange, correlation energy affect the compressibility of the semiconductor across a wide range of density, temperature, and external magnetic. • Spin, temperature, and carrier density dependence of electron compressibility in quantum wires is analyzed. • Compressibility increases with external magnetic and temperature. • Compressibility has a clear minimum at low every external magnetic an at low carrier density below 1*106 cm−1. • The results are consistent with experimental results. [ABSTRACT FROM AUTHOR]

• Optical conductivity in magnetic atoms embedded in honeycomb lattices is studied. • Anisotropic longitudinal and transverse currents, controlled by photon frequency, are predicted. • Magnetic phases play a crucial role in anisotropic transport. • Valley Hall current can be controlled. • Predicting optoelectronic devices with stable transmission, operating over a wide range of light frequencies. We investigate the optical properties of a hexagonal lattice with spin-spin interaction. Transition metal atoms with 3d-orbitals, for example Cr, Fe, Co, Ni, can be embedded in the lattice, exhibiting a strong magnetic moment. Spin polarization controls the magnetic phases, which can be ferromagnetic (FM), ferrimagnetic (FR), or antiferromagnetic (AFM). The behavior of electrons can resemble both massless and massive particles when varying the angle between spin-spin interactions. This leads to the investigation of the electronic properties of alternative materials, such as MXenes, for optoelectronic devices with stable transmission across a wide range of light frequencies from near-infrared to the ultraviolet regime. Furthermore, anisotropic optical conductivity and transmittance could be used to identify the spin orientation and atomic arrangement in magnetic materials. [ABSTRACT FROM AUTHOR]

Vanadium Nitride based magnetic heterostructures have opened up unprecedented opportunities in the field of spintronics owing to their half metallicity and a high value of spin polarization. In this paper, a tight-binding model of epitaxially grown VN/AlN/VN heterostructure is developed with different types of bonding at the left and right interface. The Slater–Koster tight-binding scheme is used to obtain the on-site and hopping energies of the model by fitting them to bulk DFT band structures. Electron transport across the VN/AlN/VN heterostructure is then studied using the non-equilibrium Green's function method, which works well within the tight-binding framework. An asymmetry in the interface bonding of the structure was found to produce a resonance peak in the transmission spectra at around 0.5 V. Beyond 0.5 V, the tunnel junction registers a large antiparallel current resulting in a negative tunnel magnetoresistance. Moreover, the presence of a magnetic impurity in the insulating barrier enhances tunneling across the junction resulting in a large current that decreases with the value of intra-atomic Coulomb repulsion, U , at the impurity site. • Half metallic Vanadium Nitride acts as a spin injector. • An asymmetric interface leads to a negative TMR. • Magnetic impurities in the barrier enhances the current. • Manipulation of spin valve current by impurity spin coupling. [ABSTRACT FROM AUTHOR]

• A 2D imaging spin-filter for photoemission electron microscopy is introduced. • Spin–orbit scattering at Au/Ir(001) offers up to 104 detection channels. • Two spin-components are detected, scattering at an oxygen passivated iron film. • A method to detect all three spin components is outlined. A two-dimensional imaging spin-filter for photo-emission electron microscopy is described. The spin-filter is capable of imaging the electron spin polarization of either real space or momentum space electron distributions. As a scattering target either Au/Ir(001) comes into use, where spin sensitivity results from using spin–orbit scattering or Fe(001)-p(1×1)O that exploits exchange interaction. Both scattering targets were characterized with respect to their working points and Sherman function in a separate setup. Spin-polarization images of secondary electrons from the magnetic domains of a poly-crystalline iron sample are shown using both scattering targets. Images with a spin-filter using Au/Ir(001) show more than 104 discrete detection channels which increases the effective two-dimensional figure-of-merit (FoM) of this spin-filter by four orders of magnitude compared to single-channel spin detectors. Using the exchange scattering target two spin-components have been imaged for the first time. A method to detect all three spin-components is also outlined. [Display omitted] [ABSTRACT FROM AUTHOR]

Silicon (Si) is the dominant material in the semiconductor industry with some novel properties, the introduction of germanium (Ge) and vacancies lead to special electronic and magnetic properties. In this work, the effects of spin-polarized electrons regulate the electronic and magnetic properties for substituted Ge in bulk crystalline Si (Ge Si) with vacancies and electrical charge states introduced are investigated based on first-principles calculations. It is found that the electron spin density of Ge-vacancy (GeV) and Ge-divacancy (GeV 2) complex structures is redistributed, the number of the defect energy levels is changed, and the magnetic moment on atoms appears when vacancies are introduced in Ge Si. In addition, the distribution of the defect energy levels in the band gap is affected by charge states (negative and neutral), resulting in changes in the degree of spin-splitting, orbital occupation and electron filling, energy levels degeneracy, and the magnitude of the magnetic moment. These results show that the spin polarization on Ge Si with vacancies and charge states, the number and the distribution of the vacancies around Ge, all play important roles in regulating the magnetic moments, magnetic properties, and the magnitude and distribution of defect energy levels. [ABSTRACT FROM AUTHOR]

In the present work, structural, electronic, magnetic, elastic, mechanical, thermal and optical properties of XCrAl (X = Fe, Co, Ni, Cu) Half-Heusler (H–H) alloys were explored. First-principles study based on the non-polarized and spin-polarized density functional theory (DFT) were employed to get the geometrically relaxed unit cell structures of H–H alloys of investigation. The larger lattice constant values were found due to the spin polarization and the magnetic moments were calculated from the spin density of states (DOS). The higher values of magnetic moments make XCrAl alloys suitable for magnetic device applications. The computational electronic structure analyses at zero applied pressure confirm the zero energy band gap of XCrAl alloys which displayed metallic nature for all the compounds. From the elastic constants calculations, all the studied alloys were found mechanically and thermally stable. The values of melting temperatures were obtained in the range from 2072 to 1883 K and the calculated Debye temperatures followed the same manner of variation. Among the studied compounds, FeCrAl exhibits highest melting temperature and lattice thermal conductivity with the value of 12.94 Wm−1K−1 at 300 K which is in good agreement with the other reported results. These investigations suggest that, FeCrAl is relatively more suitable in accident-tolerant fuel (ATF) cladding material applications over the common Zr-based cladding rods. The frequency dependent optical properties of the studied H–H alloys were also explored comprehensively and the examinations indicate that, XCrAl (X = Fe, Co, Ni, Cu) alloys can also be the good choice for ultraviolet (UV) based optical device applications as they have high absorption coefficient of >200 × 104 cm−1 and maximum reflectivity of >94% in the UV region. • The physical properties of XCrAl (X= Fe, Co, Ni, Cu) half-Heusler (H-H) alloys were studied comprehensively by DFT based first-principles study. • The structural relaxation was done by the geometry optimization at zero applied pressure. • The metallic nature for all the studied compounds is obtained from band structure and density of states (DOS) calculations. • The elastic, mechanical and thermal stabilities were successfully investigated and high melting temperatures were found. • Among the studied alloys, FeCrAl is found more suitable for high-temperature applications and XCrAl H-H alloys also possess interesting optical responses in the ultraviolet (UV) region. [ABSTRACT FROM AUTHOR]

• This article reviews recent work on chirality-induced spin selectivity (CISS), which has been extensively studied over the last two decades. • While current-induced spin polarization in chiral molecules is widely accepted as the fundamental principle of the CISS, only a few studies on bias-current-free CISS have been reported. • The possible mechanism of bias-current-free CISS, i.e. thermally driven broken-time-reversal symmetry of chiral molecules at the interface is discussed. Chirality-induced spin selectivity (CISS) has been extensively studied over the past two decades. While current-induced spin polarization in chiral molecules is widely recognized as the fundamental principle of the CISS, only a few studies have been reported on bias-current-free CISS, where there is no bias electric current in chiral molecules. Recent studies on the chirality-induced exchange bias and current-in-plane magnetoresistance (CIP-MR) effects using chiral molecule/ferromagnet bilayer systems indicate that chiral molecules at the interface possess thermally driven broken-time-reversal symmetry, which induces bias-current-free CISS, i.e. a spontaneous effective magnetic field in the system. In this paper, we briefly review CISS-related phenomena in terms of the symmetry and discuss the mechanism of bias-current-free CISS. We also discuss the possibility of the linear magnetoelectric effect of chiral molecules, which arises from the spin polarization at the edges of molecules with metallic contacts, and its potential impact on the observed CISS phenomena. [ABSTRACT FROM AUTHOR]

In this study, the author theoretically investigates the effect of the external Rashba interaction on the properties of spin transport in a magnetic MoS 2 superlattice. The results show that the spin conductance of the magnetic MoS 2 superlattice heavily relied on the applied external magnetic field in the presence of more than one barrier. Moreover, the spin conductances with and without the spin-flip exhibited a gap, the size of which increased with the number of the barriers in the superlattice. The spin-dependent conductance in the magnetic MoS 2 superlattice could be controlled by changing the number of barriers to the superlattice and the strength of the Rashba interaction. The spin polarization exhibited oscillating behavior in terms of the energy of the incident electron and the strength of the Rashba interaction. Remarkably, full-spin polarization could be achieved by using an MoS 2 superlattice under an external magnetic field. The results of this study confirm that the magnetic MoS 2 under the Rashba interaction can be used in spintronics and electronics devices in the future. [Display omitted] • Transport properties were investigated in a magnetic MoS 2 superlattice. • The spin conductivity with and without spin flip has a gap. • Spin-dependent conductivity can be controlled by changing the number of barriers. • Direction and value of the spin polarization can be changed by magnetic field. • By a magnetic MoS 2 superlattice, the 100% spin polarization current can be obtained. [ABSTRACT FROM AUTHOR]

Time-resolved photoluminescence spectroscopy under the excitation of circular polarization modulated continuous-wave laser can quantitatively extract the electron spin polarization degrees and electron spin relaxation time, providing an important tool to detect electron spin dynamics. We theoretically analyze the electron spin dynamics in four-, six- and eight-energy level systems under the excitation of circular polarization modulated continuous-wave laser by solving the rate equations of electron population. The relationship between the time-resolved photoluminescence spectra and the spin information of the spin system is provided. The electron spin polarization degrees of the ground and excited states, the establishment time of the steady-state spin polarization and the electron spin relaxation time can be directly derived from the time-resolved photoluminescence spectra. And the theoretical model is verified experimentally by the measurement of electron spin dynamics in Ce3+: YAG crystal. • The relationship between the time-resolved PL spectra and the spin information of the multi-energy level system is provided. • The equations to extract the spin information from the time-resolved PL dynamics for multi-energy level systems are unified. • The proposed theoretical model for multi-energy level spin systems is verified experimentally. [ABSTRACT FROM AUTHOR]

Based on Dresselhaus spin-orbit-coupling effect in a layered semiconductor microstructure, an electron-spin filter is proposed. It is found that an obvious spin polarization effect appears and is related to electron energy and in-plane wave vector. It is also found that both magnitude and sign of spin polarization can be controlled by strain engineering or layer's thickness. This layered-semiconductor microstructure can act as a tunable spin filter. • Spin-polarized transport is investigated in InSb/GaSb modulated by Dresselhaus spin-orbit coupling. • An obvious spin polarization appears. • Spin polarization ratio is manipulated by strain engineering or layers' thickness. • A electron-spin filter is obtained for spintronics device applications. [ABSTRACT FROM AUTHOR]

We have investigated how the structural and electronic properties of armchair GaN nanoribbons (AGaNNR) are affected under the influence of fluorine (F 2) molecule adsorption. The adsorption was modeled considering different combinations of adsorption sites and orientations of the molecule. It was revealed that adsorption of F 2 -molecule over AGaNNR proceeds via exothermic process. The magnetic stabilization is also noticed which is greater than the thermal excitation energy and pledges magnetic properties for practical applications. The adsorption of F 2 molecule causes a semiconductor to metallic transition in all the considered structures. The concentration effects were also investigated which revealed remarkable findings and may further lead to spintronic-device applications. [Display omitted] • Fluorine molecule (F 2) adsorption is energetically feasible on armchair GaN nanoribbons (AGaNNR). • A p-type character is noticed for F 2 adsorption on AGaNNR. • The adsorbed molecule gets dissociated and the two F atoms make stable chemical bonds with nearest Ga. • The charge density and ELF plots confirm the ionic bonding between F and the host ribbon. [ABSTRACT FROM AUTHOR]

For the purposes of fitting the characteristics of the Magnesium sulfide (MgS) and, Magnesium selenide (MgSe) semiconductors in Spintronic applications, a theoretical ab-initio investigation of Transition metals (TM=Ti, V, Cr, Mn, Co, Ni) substitution is performed. The equilibrium properties have been studied in the zinc-blende phase of MgS and MgSe. The effects of temperature and pressure on the structural, electronic, thermodynamic, and magnetic properties of our systems are explored as well. It is found that the introduction of the TMs in MgS and MgSe brings out a half-metallic ferromagnetic behavior with 100% polarization around Fermi level in Ti, V, Cr, Co and Ni cases, contrary to the Mn case where the half-metallic feature does not appear. The double exchange mechanism was the mechanism responsible for magnetism in these systems. Finally, the high Curie Temperate (T c) of the ferromagnetic systems reveals that Ti, Cr and V substitutions could play a significant role in spintronic applications. • Electronics & magnetism merge, yielding Innovative materials & components for Spintronics. • Half-metallic magnets are 100% spin polarization; ideal for Spintronic apps. • Investigating transition metal substitutions (Ti, V, Cr, Mn, Co, Ni) in MgS and MgSe. • Half-metallic ferromagnetic found for Ti, V, Cr, Co, & Ni substitutions, except Mn. • High Curie temperature for Cr, V, and Ti substitutions above room temperature. [ABSTRACT FROM AUTHOR]

Bilayer thin films of multiferroic oxide BiFeO 3 and metallic alloy Fe 97 Si 3 deposited by RF-magnetron sputtering have been investigated to understand spin polarized electron transport across bilayer interface. Effect of BiFeO 3 thickness variation on magnetic and magnetotransport properties of bilayer thin films has been analyzed. An induced unidirectional magnetic anisotropy in bilayer thin films has been observed by interface coupling between antiferromagnetic BiFeO 3 and ferromagnetic Fe 97 Si 3 spin magnetic moments. Increasing interface roughness with increase in BiFeO 3 film thickness has been found to be a regulatory factor for inducing in-plane unidirectional anisotropy and exchange interaction at bilayer interface. A high magnetic moment ∼315 emu/cc originated at room temperature by uncompensated interface spin density has been measured in 30 nm thick BiFeO 3 film. Magnetic inhomogeneities at interface give rise to a spin glass like phase responsible for spin flip scattering at bilayer interface. Enhanced low field magnetoresistance ∼30% in 60 nm thick BiFeO 3 film is ascribed to intensified scattering from disordered interface states with increasing BiFeO 3 thickness. Magnetodielectric measurements (applied magnetic field 1 kOe) have revealed five times increase in relaxation time of charge carriers inside grains confirming intergrain charge transport dominated by alignment of magnetic moments of nearby grains via exchange coupling. High value of magnetoresistance ∼46% in 60 nm thick film of increased grain size is due to enhanced critical length for charge transport. Observed room temperature magnetoresistive properties of BiFeO 3 /Fe 97 Si 3 thin films are critical for developing multiferroic antiferromagnetic based spintronic devices. Image 1 • High value of room temperature magnetoresistance ∼46% obtained in 60 nm thick BiFeO 3 is significant to develop AFM based spin filters. • Interface roughness was found a key factor to determine magntoresistive and magnetic properties of BiFeO 3 /Fe 97 Si 3 bilayer. • Soft magnetic alloy Fe 97 Si 3 has been integrated with Bismuth Ferrite for the first time to raise its magnetoresistance values by introducing Si scattering centers. • A significant increase in both high field magnetoresistance (HFMR) ∼ 46% and low field magnetoresistance (LFMR) ∼ 30% has been obtained at room temperature. • The above study is also important to develop multiferroic tunnel junctions and sensors functional at room temperature. [ABSTRACT FROM AUTHOR]

The rare earth elements are extensively incorporated in combination with alloys to fill up the demanding gaps of applications in future technologies like thermoelectrics. We give detailed prediction of electronic, magnetic, mechanical, thermoelectric, thermodynamic and optical properties of YCoTiX (X = Al, Ga, Si, Ge) quaternary Heusler alloys. The ground state properties reveal the alloys possess the LiMgPdSn-type structure with F -43 m space group. The spin polarized band structure give us a half-metallic nature at optimized lattice parameters. The minority spin band gaps are found to be indirect with calculated values as 0.53 eV for YCoTiAl, 0.61 eV for YCoTiGa, 0.71 eV and 0.62 eV for YCoTiSi and YCoTiGe, respectively. The total magnetic moment follow the Slater-Pauling curve rule of (M = Z tot – 18). Similarly, the optical properties of these alloys depict the similar behavior of electronic states near the Fermi level with substantially spins oriented along the direction of magnetization in all the alloys. The thermoelectric coefficients are investigated to infer their stand for waste heat recovery systems, where Seebeck coefficients detail their n -type behavior. Conversion efficiency is established using the dimensionless figure of merit, zT calculated as 0.75 at 550 K for YCoTiAl, 0.14 at 750 K for YCoTiGa and 0.31 at 750 K for both YCoTiSi (Ge). Thermodynamic parameters convey that all the alloys possess no anomalies with respect to phase transition or instabilities. • Predicted Heusler alloys are new class of functional materials with perfect half-metallicity. • They present robustness with respect to variation of lattice constant. • They have well established thermoelectric response over high temperature range. • They present good opto-electronic response with far-ultraviolet photo detector applications. • Anisotropic in nature, possibility of micro cracks at growing process. [ABSTRACT FROM AUTHOR]

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

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

We present our work on the structural, electronic and magnetic properties of monolayer-CdS which was subjected to bi-axial strain and hydrogenation at possible adsorption sites using the first-principles calculations. The results show that both bulk-CdS and monolayer-CdS are non-magnetic direct (Γ − Γ) band-gap semiconductors. By applying a compressive strain up to −10 % the monolayer-CdS remain direct band-gap semiconductor with a maximum band gap value of 2.11 eV. In contrast, a semiconductor to metal transition occurred at 17 % applied tensile strain. Moreover, hydrogenation on all possible adsorption sites induces ferromagnetism and p -type conductivity in monolayer-CdS. Among all possible adsorption sites, H added on the Cd-top site is the most probable site showing strong ferromagnetism and half-metallicity. The strong ferromagnetism means 100 % spin polarization is retained up to applied bi-axial strain of −5 % to +15 %. Also, half-metallicity is robust under the bi-axial strain in the range of −4 % to +2 %. To determine the strength of the exchange-coupling parameter, the FM (ferromagnetic) and AFM (anti-ferromagnetic) coupling between added atoms was investigated under the bi-axial strain of −5 % to + 5 %. Our findings show that H added on the Cd-top site makes it ferromagnetic and half-metallic above room temperature. The maximum Curie temperature T c = 651.41 K is achieved at a strain of ɛ = −2 % of ferromagnetic state. This high Curie temperature has not been achieved for any 2D material to-date. The present work provides a route to harness the ferromagnetism and thermal stability of 2D monolayer-CdS for electronic and spintronic applications. [ABSTRACT FROM AUTHOR]

The recently predicted penta-RuS 4 monolayer with high stability, large nontrivial band gap and robustness against oxidation is promising for applications in nanoelectronics. The band structure of this material exhibits unique characteristics under the uniaxial strains and we show that this feature provides the possibility of generating the controllable charge and spin beams. We calculate the transport coefficients for the strain barrier in this monolayer, generally, in the presence of a magnetic filed and an applied voltage. Charge transport through the strain barrier shows that we can generate electron beams which their directions are adjusted by the strain and the external voltage. Also, we show that by addition of a magnetic field, we can generate fully spin polarized electron beams, emerging at angles determined by the applied voltage. These features can be of great importance in designing splitters and spin lenses. The possibility of changing the perfect polarizations between the two spin states, easily by altering the voltage, highlights the potential application of RuS 4 monolayer for spintronic switches. Our calculations demonstrate that for the very small lengths of the strain barrier, the tunneling effect of evanescent waves dominates the contributions of the itinerant waves in transport process. We show that this unique phenomenon is related to the shape of the band structure. • Generation of electron beams with directions adjustable by strain and voltage • Easy switch of the perfect spin polarization by altering the voltage • Perfect spin-polarized beams with tunable direction by using a magnetic field • The tunneling effects of the evanescent waves overcome the traveling waves [ABSTRACT FROM AUTHOR]

The Aim of this paper is to study the properties of spin transport for ferromagnetic graphene superlattice unit cell junction taking into account the induced ac-field at different frequencies. Transfer matrix method is used for both spin alignments to calculate the conductance in terms of which spin polarization and giant magneto-resistance are also expressed. The results show that an oscillatory behavior is strongly exhibited by the three calculated quantities. These oscillations could be explained by the mutual effect between the magnetic field of the ferromagnetic insulator EuO, which causes spin filtering, and the induced photon energy of applied ac-field. The present research might have a scientific potential in the design and understanding of graphene superlattice based spin filters by optimizing the different parameters studied in this paper. • Spin-dependent transport in ferromagnetic graphene superlattice junction is studied under ac-fields with range of frequencies and different lengths. • interaction between the induced photon and the spin minibands results in oscillating behavior of the conductance. • The conductance ripples around a background average value with high spikes over semi periodic intervals of the gate voltage. • The anti-parallel spin alignment exhibits the same overall behavior with a shift towards higher gate voltages. • Energy of induced photons in selected range of frequencies enhances spin transport. [ABSTRACT FROM AUTHOR]

• The intrinsic magnetic properties can be modulated by geometrical configuration. • The spin degeneracy semiconducting ground state can be lifted by electric field. • The half-metallicity can be induced at critical electric field strength. It has been known for a long time that graphene flakes of certain geometries can develop spontaneous spin polarization. Here, it is studied what happens when two triangular graphene nanoflakes, possibly different sizes, are placed in close proximity with AB (Bernal) stacking. The results of first-principles calculations show that the magnetic ground state of the bilayer system depends on the different sizes of the two nanoflakes, and spin-related energy gap can be controlled with external electric fields. Under certain circumstances, the system even can be tuned into half-metallic nature, which might potentially be exploited in future spintronics applications. [ABSTRACT FROM AUTHOR]

In degenerate quantum plasma the energy behavior of electrostatic modes propagating perpendicular to the external magnetic field is studied by employing the separated spin evolution quantum hydrodynamic (SSE-QHD) model. This model reveals that spin electron cyclotron wave (SECW) appears additionally with the upper hybrid wave (UHW). In case of SECW, the curves for the energy flow speed at different levels of spin polarization effect flip over at a particular value of wave number. The spin polarization effect enhances the energy flow speed before this value of wave number and then suppresses it afterward. The energy flow speed is enhanced by spin polarization effect in the entire range of wave number for the propagation of UHW. The Bohm potential effect drastically increases the energy flow speed at high wave number domain in both the waves. This study may find its applications to understand the energy behavior inspin polarized solid state plasmas • Studied the energy flow speed for the propagation spin electron cyclotron wave (SECW) and upper hybrid wave. • Examined how the spin polarization and Bohm potential influence the energy flow speed. • Results are applicable to environments like solid state plasma. [ABSTRACT FROM AUTHOR]

We study the spin transport in bilayer graphene nanoribbons (BGNs) in the presence of Rashba spin-orbit interaction (SOI) and external gate voltages. It is found that the spin polarization can be significantly enhanced by the interlayer asymmetry or longitudinal mirror asymmetry produced by external gate voltages. Rashba SOI alone in BGNs can only generate current with spin polarization along the in-plane y direction, but the polarization components can be found along the x, y and z directions when a gate voltage is applied. High spin polarization with flexible orientation is obtained in the proposed device. Our findings shed new light on the generation of highly spin-polarized current in BGNs without external magnetic fields, which could have useful applications in spintronics device design. • Investigate the spin polarized transport properties in bilayer graphene nanoribbons in the presence of Rashba spin-orbit interaction. • Spin polarization can be significantly enhanced by the interlayer asymmetry or longitudinal mirror asymmetry produced by external gate voltages. • Spin current with high spin polarization and high flexibility in the orientation can be obtained in the proposed device. • The proposed device could have useful applications in spintronics. [ABSTRACT FROM AUTHOR]

The property of matter-wave vector solitons in a spin-1 Bose-Einstein condensate with spin-orbit and Zeeman couplings is investigated by multiscale perturbation method. The excitation spectrum and the corresponding state vectors of the system are obtained analytically, and they can be adjusted by the parameters of the system. The bright and dark vector solitons are formulated by reducing the three-component coupled Gross-Pitaeviskii equations to a standard nonlinear Schrödinger equation, which has the solutions of the bright and dark solitons with positive or negative mass depending on the product of the effective dispersive and nonlinear coefficients. The moving vector solitons are demonstrated by adjusting specific momentum near the energy minimum. Finally, the magnetized features of the vector solitons are discussed by the spin polarization of the system. • The excitation spectrum for the vector solitons, determined by the parameters of the system, is obtained analytically. • The analytical bright and dark vector solitons are formulated and the moving solitons are demonstrated by adjusting specific momentum. • The solitons with positive or negative mass depending on the product of the effective dispersive and nonlinear coefficients are analyzed. • The magnetized features affected by spin-orbit and Zeeman couplings are discussed by the spin polarization of the system. [ABSTRACT FROM AUTHOR]

• Our paper introduces a spin transport model based on the drift-diffusion equation for non-collinear magnetic configurations taking account of diffuse interfaces. • The spin dephasing term is required to introduce into the spin transport model since it is responsible for the enhancement of spin-transfer torque and magnetoresistance (MR). We propose a theoretical model to study the spin transport, particularly the interfacial resistance in a noncollinear system with a diffuse interface. The realistic interface region arising from the sputtering process is first modeled by using Fick's law. Subsequently, the spin transport behavior in magnetic system is determined via a generalized spin accumulation model taking into account spin dephasing term. Our model is able to deal with magnetic systems with arbitrary orientation of magnetization by employing the transfer matrix approach. The model is first used to investigate spin accumulation in a bilayer system consisting of a ferromagnet (FM) and a non-magnet (NM). The influence of important transport parameters: spin dephasing, interdiffusion, injected current density and spin polarization on magnetoresistance (MR) are studied. Next we investigate the transport properties of a FM/NM/FM system where the interface disorder giving rise to enhanced spin dephasing is modeled. We found that the interdiffusion of the FM/NM/FM interface gives rise to large spin scattering, which enhances the GMR. The results also show that including the disorder arising from interface diffusion is an important contribution to the transport properties. [ABSTRACT FROM AUTHOR]

The optimized plots of MgBeO 3 , CaBeO 3 , SrBeO 3 and BaBeO 3 in FM state by GGA approximation (b) Crystal Structure designed by Xcrysden taking 2 × 1 × 1 unit cell. • The structural, mechanical and thermodynamic stability ofperovskites. • Room temperature ferromagnetism. • Half metallic ferromagnets with hundred percent spin polarization. • Exchange mechanism exceed the exchange energy than crystal field energy. • The cause of ferromagnetism is spin of electron rather than clustering effect. We investigate the Half-metallic ferromagnetism and optical behaviors of XBeO 3 (X = Mg, Ca, Sr and Ba) using full-potential linearized augmented plane-wave method. The structural and thermodynamic stabilities are elucidated in terms of the calculated tolerance factor and enthalpy of formation, respectively. The room temperature (RT) ferromagnetism is shown by computing the Curie temperature and spin polarization. The strong hybridization between p -states of alkaline earth metals and 2 p -states of oxygen near the Fermi level results total magnetic moment of 2μ B. The ferromagnetism occurs due to holes those result in the exchange interactions between the p-states of alkaline earth metals and oxygen. The potential optical applications are also suggested by computing the dielectric constant and refraction. [ABSTRACT FROM AUTHOR]

Spin dependent transport in one-dimensional four-terminal rings (FTRs) is investigated in the presence of the Rashba spin-orbit coupling (RSOC). In the absence of the RSOC, the conductances as a function of the electron wave vector show resonant behavior for symmetrical configurations. For asymmetrical configurations, the conductances show peculiar zero-conductance resonances, and two kinds of conductance zeros have been found. In the presence of the RSOC, the original conductance zeros disappear as new conductance zeros are generated. Moreover, two kinds of symmetry relations have been found in the conductances, the spin dependent conductances and the spin polarizations. For the FTRs with axial or central symmetry, the phase-locking effect has been found in terminal 2, where there is no spin polarization. Under a weak magnetic field, the Zeeman term is treated by a perturbation, and it is found that the Zeeman effect is obvious for weak RSOC. • The transmission coefficients for the four-terminal rings (FTRs) are derived analytically. • Two kinds of conductance zeros have been found in the conductances. • The phase-locking effect has been found in terminal 2 for the FTRs with axial or central symmetry. • The results are extended to the case of a weak magnetic perturbation. [ABSTRACT FROM AUTHOR]

We calculated the electronic structure, magnetism and optical properties of the Sc-doped, Y-doped, and (Sc, Y)-codoped anatase TiO 2 (101) surface using a projector augmented wave (PAW) method with GGA + U approximation. Sixteen doping systems were considered in the present work. The lattice distortion results in the generation of an internal local electric field. In addition, the difference between positive and negative spin charge densities leads to the generation of magnetism. With the exception of the Sc@in2 system, the width of band gap of the other doping systems increases to varying degrees, leading to a blueshift of the absorption edge. The photocatalytic activity of all the doping systems was improved to different degrees. The absorption intensity and absorption range of the Sc@in2&Y@O13 system in the visible-light region is the highest amongst all doping systems. This mainly attributed to the formation of hole states and the presence of impurity bands. • Lattice distortion can result in the generation of local electric fields. • The Sc@Ti5&Y&Ti6 mainly induce polarization of O-2p spin electrons and less induce polarization of Ti-3d spin electrons. • Except for Sc@in2, the width of band gap of the other doping systems increases to varying degrees. • The absorption intensity and absorption range of Sc@in2&Y@O13 is the highest amongst all doping systems. [ABSTRACT FROM AUTHOR]

We derive relativistic hydrodynamic equations with a dynamical spin degree of freedom on the basis of an entropy-current analysis. The first and second laws of local thermodynamics constrain possible structures of the constitutive relations including a spin current and the antisymmetric part of the (canonical) energy-momentum tensor. Solving the obtained hydrodynamic equations within the linear-mode analysis, we find spin-diffusion modes, indicating that spin density is damped out after a characteristic time scale controlled by transport coefficients introduced in the antisymmetric part of the energy-momentum tensor in the entropy-current analysis. This is a consequence of mutual convertibility between spin and orbital angular momentum. [ABSTRACT FROM AUTHOR]

In this study, the half-metallic behavior and magnetic properties of various (001) surfaces for Y 2 CrSn Heusler alloy were investigated using the spin-polarized first-principles method. The spin polarizations of the standard stable YSn-terminated and artificial stable SnSn-terminated (001) surfaces were −96.9% and −95.8%, respectively, using the generalized gradient approximation (GGA) method (−69.2% and −83.0% using the GGA + U method), and thus the two surfaces have potential use in spintronic devices. The spin polarizations of the standard YCr-terminated, artificial YY-terminated, and artificial CrCr-terminated (001) surfaces were only −43.0%, 29.3%, and −40.8%, respectively, using the GGA method (−63.2%, −67.9%, and −44.4% using the GGA + U method). The atomic magnetic moments (AMMs) of the Y and Cr atoms in the outmost layer changed greatly due to the surface states, but little change was found in the AMMs of atoms near the central layer. The average AMMs obtained for the Sn, Y, and Cr atoms using the GGA + U method were only slightly larger than the corresponding AMMs determined using the GGA method. Image 1 • Spin polarizations of stable YSn and SnSn-term (001) surfaces were high. • Spin polarizations of unstable YCr, YY, and CrCr-term (001) surfaces were low. • Atomic magnetic moments of Y and Cr atoms changed little in the outermost layer. • Little change in atomic magnetic moments of atoms near the central layer. [ABSTRACT FROM AUTHOR]

• Fully Relativistic PAW band structure of Re(0001) surface. • Identification of surface states and resonances. • Analysis and discussion of the spin-polarization of the surface states. • Comparison with the surface states of Au(111), Pt(111), Ir(111), and Os(0001). We study the electronic structure of the Re(0001) surface by means of ab-initio techniques based on the Fully Relativistic (FR) Density Functional Theory (DFT) and the Projector Augmented-Wave (PAW) method. We identify the main surface states and resonances and study in detail their energy dispersion along the main symmetry lines of the SBZ. Moreover, we discuss the effect of spin-orbit coupling on the energy splittings and the spin-polarization of the main surface states and resonances. Whenever possible, we compare the results with previously studied heavy metals surfaces. We find empty resonances, located below a gap similar to the L-gap of the (111) fcc surfaces, that have a downward dispersion and cross the Fermi level, similarly to the recently studied Os(0001) surface. Their spin polarization at the Fermi level is similar to that predicted by the Rashba model, but the usual level crossing at Γ ¯ is not found with our slab thickness. Moreover, for selected states, we follow the spin polarization along the high symmetry lines, discussing its behavior with respect to k ∥ , the wave-vector parallel to the surface. [ABSTRACT FROM AUTHOR]

The density functional theory (DFT) was used to analyze the electron spin competition interaction between next neighbor Ni atoms in various artificially designed structures in a nano-SiC monolayer honeycomb structure. The electronic structural, magnetic and optical properties of a monolayer SiC materials that were doped with different quantities of Ni in a specific shape are detailed in this paper. Interestingly, spin polarization appeared to occur in the structures that were doped with one Ni and 3Ni having a triangular structure. However, there was no spin polarization present in these materials prior to Ni doping, 2Ni doping with a linear structure and 4Ni doping with rhombic structure. The conduction band of the Ni-doped system moved toward the low energy direction which produced a decrease in the band gap. Calculations of the optical properties showed that Ni doping enhanced their photoconduction. It is hoped that the results of this study will have encouraging implications for the application of photoelectric devices and controllable magnetic materials. • Ni structural doping induced spin polarization on the nano-SiC film. • Band gap reduction caused by doping Ni atoms in the system. • There was a frustrated exchange interaction between the next neighboring Ni atoms in the triangle structure. • Optical properties of the doped material showed that Ni doping improved photoconductivity. [ABSTRACT FROM AUTHOR]

This work presents a theoretical investigation on the electronic properties of double atomic carbon chains bridging graphene electrodes with density functional theory in combination with non-equilibrium Green's function. The influence of strain on the conductance of atomic carbon chains is significant. However, the coupling effect between adjacent chains dominates the intrinsic transport of double atomic carbon chains. For the coupled double atomic chains, the electron conductance of even-numbered atomic chains is significantly enhanced, while the electron conductance of odd-numbered atomic chains decreases to a certain degree, and the dependence of the conductance of double atomic chains on electrode configuration is stronger than the corresponding single atomic chain. More intriguingly, the coupled double atomic chains exhibit excellent spin-filtering properties with antiparallel spins on two electrodes. The current spin polarization stems from the coupling-induced changes of electron density and band offset reaches 100%. The coupled double atomic carbon chains have great potential application in spintronic devices and carbon-based field-effect transistors. • Coupling of carbon atomic chains increase the average conductance of atomic chains. • Coupling of carbon atomic chains induces very strong spin filter effect, even reaches 100%. • MR ratios of double carbon atomic chains increase by up to 5 orders of magnitude of the single carbon atomic chain. [ABSTRACT FROM AUTHOR]

A detailed experimental and theoretical investigations on the origin of room temperature ferromagnetism in Fe doped CdS diluted magnetic semiconductor is reported in the present study. X-ray diffraction results reveal the cubic zinc blende CdS structure with an average crystallite size of 2 nm–3 nm which is in concurrence with the Transmission electron microscopy results. UV–visible spectroscopy depict the enhancement of optical band gap of Fe doped CdS nanoparticles compared to the bulk CdS as a result of the quantum confinement effect. Photoluminescence spectra revealed the presence of Cd2+ and S2− defect states in the nanoparticles in addition to the fluorescence quenching effect. FTIR results demonstrate the stretching vibrations of Cd S bond. Magnetic study confirms the existence of room temperature ferromagnetic ordering in the nanoparticles for the lower concentration of Fe, as a result of spin polarization induced by the Fe atoms to the nearest neighboring S atoms. At higher concentration of Fe, the enhanced antiferromagnetic interaction between short range Fe ions suppresses the ferromagnetic ordering. Theoretical calculations demonstrate the half metallic nature of Fe doped CdS system with strong p-d hybridization between the Fe-d states and the S-p states which results the room temperature ferromagnetism. • DFT calculations are performed to investigate the ferromagnetic ordering in the Fe doped CdS nanoparticles. • Fe doped CdS system shows half metallic properties. • The ferromagnetic ordering is due to p-d exchange interaction between the localized d spins of the Fe ions and the free delocalized carriers. • p-d hybridization between the d states of Fe and the p states of S are observed in the Fe doped CdS system. [ABSTRACT FROM AUTHOR]

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

We report a study on the influence of microstructure on the magnetic and electronic properties of nanoscale Sr 2- x La x FeMoO 6 materials. The temperature dependence of the saturation magnetization of the samples in the low temperature range follows the spin wave theory which is described by a T 3/2 law. The analysis of the temperature dependence of the conductivity of the sample with x = 0 shows distinct mechanisms of spin-dependent tunneling and spin-independent hoping channels. Up on La substitution, additional metallic-type conduction paths appear which reduces the resistivity of the samples and also changes its temperature dependence behavior. Spin polarization as a function of temperature was obtained via fitting the MR curves recorded at different temperatures using the spin-dependent elastic tunneling model with correction for the spin-independent conductance. At a temperature 5 K, the spin polarizations of the samples are found to be roughly proportional to the net magnetic moment. Moreover, their values are considerably higher than those derived from theoretical calculations for the double perovskite lattices with the same antisite disorder levels which reveals an inhomogeneous distribution of the antisite defects in the samples. The decay rate of the spin polarization with increasing temperature is faster for the samples with a larger amount of antisite defects. • Sr 2- x La x FeMoO 6 samples (x = 0 – 0.4) were prepared by using sol-gel method and heat treatment in H 2 atmosphere. • Temperature dependence of saturation magnetization follows the Bloch law (∼ T 3/2). • Electrical conduction mechanisms were analyzed. • Spin polarization values were determined based on magnetoresistance data in temperature range 5–300 K. [ABSTRACT FROM AUTHOR]

Abstract We study the transport properties of a quantum dot (QD) fabricated by a quantum anomalous Hall insulator. It is found that energy levels of the QD are quantized due to the quantum confinement effect, which leads to the appearance of the resonant-tunnelling phenomenon at low temperature. We also find that topological edge states form around the boundary of the QD, coexisting with the bulk states inside the QD. The electron transmission through the channels of the edge and bulk states drives the Fano interference, manifested as the asymmetric lineshape of the linear conductance spectrum. In addition, the spin polarization of this system is present. It shows that the spin-polarized current can be realized even in the absence of the external magnetic field, because of the breaking the time-reversal symmetry. Highlights • We study the transport through a quantum dot fabricated by a quantum anomalous Hall insulator. • Topological edge states form around the boundary of the QD, coexisting with the bulk states inside the QD. • Transmission through the channels of the edge and bulk states drives the Fano interference. • Spin-polarized current is realized even in the absence of the external magnetic field. • The spin filtering is found to be mainly induced by the bulk states rather than the edge states. [ABSTRACT FROM AUTHOR]

Abstract We study the tunneling conductance and magnetization of a correlated quantum dot coupled to external metallic leads, considering the occupancy dependent hybridization. Using a modified equation of motion approach and self-consistent perturbation theory we show that the assisted hopping processes can be responsible for appearance of a plateau in the linear conductance. This process breaks the particle-hole symmetry and is manifested in conductance and magnetization. In presence of the external magnetic field the correlated hybridization enhances the spin polarization. Highlights • The effect of assisted hopping on the transport properties of quantum dot was studied. • The plateau of linear conductance was obtained. • There was shown that the assisted hopping process breaks particle-hole symmetry of conductance. • There was shown that the assisted hopping enhances the spin polarization of quantum dot. [ABSTRACT FROM AUTHOR]

We report the magnetic behavior of isolated Fe impurity atoms in Pd 1− x U x (0 ≤ x ≤ 0.12) alloys studied through measurements of the local susceptibility (χ loc) and spin relaxation time for 54Fe nuclear probe using the time differential perturbed angular distribution (TDPAD) technique. With an increase of the U concentration in Pd-U alloys, the magnetic response of Fe, exhibiting Curie-Weiss type χ loc (T), reflects a steady decrease of the giant magnetic moment arising from ferromagnetic polarization of host Pd-4d band electrons. Concomitantly, we find an exponential rise in the spin fluctuation temperature T SF. The experimental observation of U induced suppression of giant magnetic moment of Fe in Pd is supported by ab intio electronic structure calculations based on density functional theory. The results presented here support the idea that sign and strength of spin polarization of host conduction band electrons play a crucial role on the spin fluctuation rate and hence moment stability. • Fe shows Curie-Weiss type local susceptibility in Pd-U binary alloys. • Exponential rise in Spin fluctuation temperature T SF with Uranium concentration. • The sign and strength of spin polarization of host conduction band electrons play a major role in the spin fluctuation rate. • Beyond x = 0.12 (Pd 1− x U x), the Fe atoms become nonmagnetic due to large spin fluctuation. [ABSTRACT FROM AUTHOR]