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Spintronics is an emerging field that has the potential to replace conventional electronics due to their comparatively high speed, low power consumption, and infinite endurance. The phenomena of ferromagnetism with high spin polarization in double perovskites make them the desired materials for spintronics. In the present work, the structure of Cs 2 CuCrX 6 (X = Cl and Br) and their magnetic and optoelectronic properties were studied by utilizing density functional theory (DFT). For the calculations of exchange-correlation potential, PBE-sol approximation was utilized while for the accurate measurement of electronic band structure and density of states (DOS), we employed mBJ potential. Both materials exhibit cubic structure and are thermodynamically stable as confirmed by volume optimization and negative formation energy respectively. Spin-based energy-volume optimization and values of exchange constants reveal the ferromagnetic nature of materials. It has been observed that 3-d states of Cr are responsible for ferromagnetism and have the major contribution to the net magnetic moment caused by exchange splitting. Furthermore, investigations of band structure and electronic density of states showed that both Cs 2 CuCrCl 6 and Cs 2 CuCrBr 6 were indirect bandgap (E g) semiconductors with the E g values of 1.2 eV and 0.33 eV respectively. The optical spectra of materials showed strong absorption in the ultraviolet region. Lastly, the transport and thermoelectric properties (TE) of materials were investigated in the range of temperature 300 K–800 K by using the BoltzTrap code. The transport parameter which included the electrical conductivity (σ/τ) and thermal conductivity (κ e /τ) of the materials showed a decreasing trend with temperature whereas the Seebeck coefficient (S) and Power factor (P.F) showed an increasing trend for Cs 2 CuCrCl 6 while decreases in case of Cs 2 CuCrBr 6. Furthermore, a high figure of merit (ZT) with values of 0.75 and 0.64 was obtained for Cs 2 CuCrCl 6 and Cs 2 CuCrBr 6 respectively. The results of this work are encouraging and show the capabilities of the discussed materials in the fields of spintronics, thermoelectric, and optoelectronics. [Display omitted] • This manuscript presents a comprehensive theoretical investigation into the magnetic, optoelectronic, and thermoelectric properties of Cs 2 CuCrX 6 (X = Cl and Br) double perovskites. • Through rigorous theoretical analysis, the manuscript unveils the spintronic potential of Cs 2 CuCrX 6 double perovskites, shedding light on their intrinsic magnetic properties and their suitability for spin-based electronic applications. This insight opens avenues for innovative spintronics device designs. • Delving into the optoelectronic characteristics, the manuscript elucidates the optical properties of Cs 2 CuCrX 6 double perovskites, offering valuable insights into their light-matter interaction mechanisms. • By examining the thermoelectric properties of Cs 2 CuCrX 6 double perovskites, the manuscript assesses their potential for thermoelectric applications, highlighting their ability to efficiently convert heat into electrical energy. This exploration paves the way for dual-functionality devices coupling data storage with energy harvesting capabilities. [ABSTRACT FROM AUTHOR]

The investigation focused on examining the spin polarization and thermal spin polarization transport characteristics of dual rhenium phthalocyanine (Re2PC2) molecular junctions. This analysis was conducted using first-principles density-functional theory and the non-equilibrium Green's function approach. Calculations were performed on molecular junctions in two configurations: one at a non-magnetic electrode (Au) and the other at a magnetic electrode (Ni). A comparison of the spin transport properties of the two electrodes shows significant differences. The magnetic electrode has a notable effect on the spin-polarization and thermal spin-polarization transport properties of the devices. In contrast, the nickel electrode bis-phthalocyanine rhenium molecular device exhibits perfect spin/thermal spin-filtering efficiencies in a parallel structure. The properties of the dual phthalocyanine rhenium molecular devices were significantly affected by the nature of the electrodes. This makes dual rhenium phthalocyanine molecular junctions have great potential for the development of high-performance multifunctional spintronic and spin caloritronic devices. • The nickel electrode Re2PC2 molecular device showed perfect spin/thermal SFE at parallel structure. • PDOS revealed that the transport properties of Re2PC2 molecules were strongly influenced by the magnetic electrode. • Changing the direction of the magnetic moments of the molecules and electrodes can alter the device's characteristics. [ABSTRACT FROM AUTHOR]

Spintronics is a rapidly developing field in advanced technology. It focuses on manipulating the spin of electrons to achieve high-speed data transfer, handling, and storage in order to enhance its capabilities. We conducted a systematic investigation of the ferromagnetism, electronic, and thermoelectric characteristics of spinel compounds LiFe 2 (O/S) 4. Our analysis for optimization demonstrates that ferromagnetic states exhibit great energy release compared to the antiferromagnetic states, indicating the presence of ferromagnetic behavior in the studied compounds. To evaluate the presence of ferromagnetism above room temperature, we employ the Heisenberg model to calculate the Curie temperature and spin polarization to evaluate the presence of ferromagnetism above room temperature. Additionally, a concise overview of the nature of ferromagnetism, including band structures, density of states, exchange energies and constants, hybridization double exchange model, and crystal-field energy, is provided in this research. The absorption of a shift in magnetic moment from Fe to the Li and O/S sites suggests that the ferromagnetic behavior is primarily due to the spin of electrons. Furthermore, we explore the impact of the thermal parameters on the electro-spin as well as the thermoelectric characteristics for both spin-down and spin-up states, providing insights into the energy-harvesting potential. • Half-metallic ferromagentic spinels LiFe 2 (O/S) 4. • Elastic constant are investigated for structural stability. • Electronic and magnetic properties for spintronic applications. • Magnetic moments are discussed for both compounds. • The electronic and lattice thermal conductivity are calculated for thermoelectric characteristics. [ABSTRACT FROM AUTHOR]

We study spin- and valley-dependent transport properties in a n-p–n junction of 8-pmmn borophene monolayer. We show that an exchange magnetic field can generate spin polarization in the system and a gate voltage, as a potential barrier, induces valley polarization. The valley polarization, induced by the gate voltage, is due to the anisotropic and tilted Dirac cones of borophene structure. This property is the advantage of borophene over the other 2D materials with isotropic and non-tilted Dirac cones such as graphene in which a gate potential cannot induce valley polarization. We also show that the proposed device (borophene-based n-p–n junction) can work as perfect spin and perfect valley filters. The spin and valley filters can be controlled by changing the gate voltage and/or Fermi energy. The results of this study show that borophene has a suitable potential to be used in spintronic and valleytronic devices. • Our npn junction can work as perfect spin and perfect valley filters. • Spin-up filter changes to the spin-down filter and vice versa via gate voltage. • Valley filtering by applying gate voltage is due to tilted Dirac cones. • Above property cannot occur in 2D materials with isotropic and non-tilted cones. • Borophene shows a great potential for use in spintronic and valleytronic devices. [ABSTRACT FROM AUTHOR]

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

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

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

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]

This study investigated the structural, elastic, electronic, thermal, magnetic, and optical behavior of GeGa 2 O 4 , FeGa 2 O 4 , GeFe 2 O 4 , and FeFe 2 O 4 spinel oxides based on ab -initio calculations. The results showed that the non-magnetic spinel oxide GeGa 2 O 4 exhibited remarkable physical properties due to Fe occupancy at different lattice sites within the spinel lattice. The Fe containing spinel oxides (FeGa 2 O 4 , GeFe 2 O 4 , and FeFe 2 O 4) were found to be stable in the magnetic phase in contrast to the host GeGa 2 O 4 spinel oxide. The spin polarizations of FeGa 2 O 4 , GeFe 2 O 4 , and FeFe 2 O 4 oxides were calculated as 98.5%, 98.4%, and 100%, respectively. Analysis of the elastic and mechanical properties showed that all of the spinel oxides followed the Born and Huang criteria for mechanical stability. The highest Debye temperature (θ D = 663.77 K) was determined for the FeGa 2 O 4 spinel oxide. For GeGa 2 O 4 , FeGa 2 O 4 , GeFe 2 O 4 , and FeFe 2 O 4 oxides, the calculated structural parameters (cation–anion bond lengths and average values of tetrahedral and octahedral radii) predicted the following cation distributions among the A and B atomic sites: (G e 2 +) [ G a 2 3 + ] O 4 − 2 , (F e 2 +) [ G a 2 3 + ] O 4 − 2 , (G e 4 +) [ F e 2 2 + ] O 4 − 2 , and (F e + 2) [ F e 2 3 + ] O 4 − 2 . The calculated electronic structures indicated that the host GeGa 2 O 4 spinel oxide and FeFe 2 O 4 spinel ferrite were semi-conducting and half-metallic ferromagnetic, respectively, whereas FeGa 2 O 4 and GeFe 2 O 4 oxides exhibited semi-metallic behavior. The GeFe 2 O 4 spinel oxide was found to have the highest saturation magnetization (185.79 emu g−1) and total magnetic moment (8.26 Σ B fu −1). The calculated optical properties indicated the suitability of these oxides for use in optical filters and sensors. The electronic and magnetic characteristics of these spinel oxides with excellent thermal and elastic stability suggest that they have potential uses in diluted magnetic semiconductor devices. [Display omitted] • Effects on physical properties of GeGa 2 O 4 with Fe occupancy are observed. • GeGa 2 O 4 , FeGa 2 O 4 , GeFe 2 O 4, and FeFe 2 O 4 spinels exhibit mechanical anisotropy. • Presence of Fe at A, B, and/or both sites reduces electronic, and optical bandgap. • GeFe 2 O 4 shows semi-metallic behavior with m t o t = 8.26 μ B /f.u and M S = 185.79 emu/g. • The oxides containing Fe have less threshold electronic transition energy. [ABSTRACT FROM AUTHOR]

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

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

A succinct summary of various physical characteristics of halide double perovskites Cs 2 KXCl 6 : (X = Ti and V) has been summarized using Density Functional Theory (DFT), as applied in WIEN2k simulation code. These material's stability in Fm-3 m cubic symmetry is confirmed by structural optimization, tolerance factor and elastic parameters. The electronic band structures and density of states calculated using GGA and G G A + m B J show that these materials are semiconducting in spin down channels. The crystal field splitting of d-orbitals is used to explain the semiconducting ferromagnetic nature of these Ti- and V- based halide double perovskites. The ferromagnetic character of these double perovskites is suggested by the optimization and asymmetric DOS across Fermi level. We have also discussed about the origins of half-metallic bandgap and magnetism. The total magnetic moments of the Ti and V-based double perovskites are 1 μ B and 2 μ B, respectively, with the transition metal atoms (Ti/V) accounting for the major contributions. At the Fermi level, these double perovskites have 100% spin polarization, indicating that they could be used in spintronics. • The DFT studies confirm the structural stability of double perovskites(DPs) Cs 2 KXCl 6 : X = Ti, V in ferromagnetic state at low temperature. • Structural optimization and tolerance factor confirms the structural stability of the DPs. • The DPs shows half-metallic nature in both GGA and mBJ calculations. The half-metallic character of the DPs is also supported by their integral magnetic moments. • The mechanical parameters shows Cs 2 KVCl 6 as brittle while as Cs 2 KTiCl 6 as ductile. • These DPs exhibit 100% spin polarization at the Fermi level suggests that they might be used in spintronics. • The findings may be beneficial for experimentalists to prepare these type of DPs in laboratories for commercial uses. [ABSTRACT FROM AUTHOR]

The antiferromagnetic (AFM) CrI 3 bilayer is a particularly interesting representative of van der Waals 2D semiconductors, which are currently being studied for their magnetism and for their potential in spintronics. Using ab initio density-functional theory calculations, we investigate the spin texture in momentum space of the states of the (doubly degenerate) highest valence band of the AFM CrI 3 bilayer with Cr-spin moments perpendicular to the layers. We find the existence, in the main central part of the Brillouin zone, of a Rashba in-plane spin texture of opposite signs on the two layers, resulting from the intrinsic local electric fields acting on each layer. To study the layer segregation of the wavefunctions, we apply a small electric field that splits the degenerate states according to their layer occupancy. We find that the wavefunctions of the highest valence band are layer-segregated, belonging to only one of the two layers with opposite in-plane spin textures, and the segregation occurs over nearly the whole Brillouin zone. The corresponding layer locking of the in-plane-canted spin is related to the separation in energy of the highest AFM band from the rest of the valence bands. We explain how the band interactions destroy the layer locking at the K , K ′ , and Γ points. Furthermore, we compare the layer locking of the in-plane-canted spin in our AFM bilayer system with the hidden spin polarization in centrosymmetric nonmagnetic materials, pointing out the differences in segregation mechanisms and their consequences for the layer locking. We note that a similar Rashba effect with layer locking of in-plane-canted spin could occur in other van der Waals AFM bilayers with strong spin–orbit coupling and an isolated energy band. [Display omitted] • k -space spin-texture is studied for antiferromagnetic chromium-tri-halide bilayer. • Existence of Rashba-type spin textures with opposite spin canting on two monolayers. • Segregation of wavefunctions of highest valence band on one of the two layers. • Layer locking is related to separation in energy of the highest AFM valence band. [ABSTRACT FROM AUTHOR]

Structures and the physical properties of the current physical materials and other hypothetical models can be visualized and estimated with considerable success using density functional theory. As promising materials Double Perovskites satisfy the need of fulfillment of energy requirements in current scenario. Probing and investigating such structures theoretically, saves time and curtails the expenditure. This Perspective highlights the optical response functions viz Dielectric Tensor, Polarizability, Reflectivity, Optical conductivity, Absorption Coefficient and Extinction Coefficient of the material in the presence of electromagnetic field of varying energy (0–5eV) and offers an outlook of the potential use of such properties in spintronics and sensors. In our study the effective PBE (Perdew, Burke, Ernzerhof) functional was used to investigate the electronic and optical properties of Sr 2 FeMoO 6 and the thermodynamic stability of the material was estimated using the convex hull approach. The formation energy calculated from total energies of the bulk material (SFMO) and the individual total energies of the constituent elements in their corresponding pure bulk phase indicate the simulated structure to be thermodynamically stable with an energy value of −2.533eV. The study confirms SFMO as an anisotropic dispersive medium, with non-linear optical properties wherein apart from differential rates of absorption along different axis of polarization, nonlinearity and dispersion with respect to optical conductivity, dielectric constant can also be observed. The absorptive bandwidth of the material estimated by density functional approach lies between 2 and 4.5 eV and the absorption function resembles the Gaussian curve. The optical conductivity curve indicates that Sr2FeMoO6 is a direct band gap material with a bandgap of 2.1 eV. The absorption coefficient "μ" peaks at an energy values of 3.2 eV and the material is absorptive for most part of the ultra violet region. The pourbiax analysis of the material has been presented and the stability in presence of varying chemical potentials and pH scales suggest non toxicity and stability associated with the material. The extinction coefficient "K" for the two directions of polarizing field behave analogous to their respective imaginary dielectric functions and the peak value of the extinction coefficient shoots to 0.8. The reflectivity plots indicate the maximum reflectance reaches to about 0.2 (20% reflectance) and then decreases with the increase in the energy of the perturbing field. Spin Polarization and the observed TDOS (total density of sates) APDOS (atom projected density of states) graphics suggest that Sr 2 FeMoO 6 exhibits near-half metallic behaviour and can dramatically enhance device performance by controlling speed and various other properties wherein spin can be manipulated. Consequently, SFMO can be tailored for spintronic applications especially in case of multilayered spin-operated junctions/devices and nonvolatile memory elements, quantum computing and faster data processing speeds. • The theoretical predictions reported in this paper suggest that the material Sr2FeMoO6 is a semiconducting material with a bandgap of about 2.1eV. • Spin polarization, inclines the nonconducting behaviour of Sr 2 FeMoO 6 towards half metallicity. which can be harnessed for various spintronic applications like spin valves, memory elements, faster data processing etc. • The stability analysis suggests SFMO as a stable structure with a foramtion energy of -2.533eV.. • The pourbiax diagram analysis suggests presence of mixed/solid ion phases. [ABSTRACT FROM AUTHOR]

Recent progress in spin caloritronics has boosted exploration of materials for their application in this novel field. Heusler alloys which were being hailed as thermoelectric and magnetic materials have seen uprise for their suitable properties however lack of studies featuring good coupling between magnetic and thermoelectric properties have seen little impact in the field of spin-caloritronics. Present work explored doping of transition metal in a thermoelectric half-Heusler alloys NbCoSb on Nb site to induce spin-polarization and spin-dependent transport properties. Co (Mn) doping results in 98.09% (19.38%) negative spin polarization and 0.51 μ B /f.u. (1.98 μ B /f.u.) magnetic moment. Magnetic exchange parameter shows presence of long range RKKY-type interaction in Co and Mn doped NbCoSb. On one-hand, doping of Co and Mn in NbCoSb suppressed the electronic transport properties whereas, on the other hand spin dependent Seebeck effect is introduced. The synergistic effect of magnetic and thermoelectric properties in non-magnetic NbCoSb via doping of Mn and Co shows large variation in the value of Seebeck coefficient, electrical conductivity and electronic thermal conductivity with flipping of spin-directions suggests Co rich NbCoSb as a promising candidate for spin-caloritronics application. • Well known thermoelectric half-Heusler alloy NbCoSb is studied for spin-caloritronics. • Magnetism is induced in NbCoSb with Co and Mn doping. • High spin polarization and spin dependent Seebeck effect is introduced with Co doping. • Synergistic effect of thermoelectric and magnetic properties are reported. [ABSTRACT FROM AUTHOR]

Harvesting waste heat back into electricity by exploiting the temperature difference across two ends of a nanodevice and its concomitant spin dependence has led to the emergence of a new field known as spin caloritronics. Herein, we report the spin polarized thermoelectric features in a π-stacked system comprised of (C n -C 6 H 6 –Fe–C 6 H 6 –C 13-n) n = 2. A decisive factor, the Seebeck coefficient, becomes fully spin dependent on temperature and switches from positive to negative values, which illustrates the switching of the thermoelectric behavior from a p-to n-type due to the change in the spin state from spin-down to spin-up. A relatively large thermoelectric figure of merit has been reported in the case of the spin figure of merit of the system. In this context, three major observations have been made: i) The Seebeck coefficient has a distinctive feature over two different spin channels, ii) the spin Seebeck coefficient (S s) is nearly four times larger than the charge Seebeck coefficient (S c), and (iii) the spin thermoelectric figure of merit (Z S) rises by 80% with respect to charge thermoelectric figure of merit (Z C) under thermal bias. Our results have been well explained through the analysis of temperature dependent transmission spectra of the system. The emergence of a relatively large spin Seebeck coefficient allows us to measure the pure spin current of the system as well as extending the devices application from simple memory (MRAM) devices to on-chip energy harvesting systems. Variation in the spin and charge thermoelectric figure of merit and spin dependent Seebeck coefficient with thermal bias. [Display omitted] • A clean and green energy solution to the massive waste heat generated in a circuit is thermoelectric materials. • Modification in thermoelectric feature against the spin polarization of tunneling electron has developed a new but virgin domain of Spincaloritronics. • Thermoelectric features are analysed mainly through ZT, spin polarized electrical conductivity, spin polarized Seebeck coefficient, In Spincaloritronics, one would have separate figure of merit for charged part and spin part as well as separate charge and spin Seebeck coefficient. • On an average Spin Seebeck coefficient (S s) is approximately four times larger than its charge counterpart (S c) and there is nearly 80% rise in Z S from Z C. Most, significant observation is switching in thermospin behavior from n to p type due to spin reversal. • Dissimilar behavior over two different spin channels certainly exemplify the appearance of spin dependent Seebeck effect with switching action from p to n type due to spin reversal. [ABSTRACT FROM AUTHOR]

The electronic structure and magnetic properties of the SnO 2 (001) surface doped with a nonmetal (C or N) and a transition metal (Co or Ni) were studied by first-principles calculations based on density functional theory. The pristine SnO 2 (001) surface is a nonmagnetic insulator. Although the two-coordinated oxygen vacancy (V O2c) has the lowest formation energy, it cannot produce spin polarization on the SnO 2 (001) surface, while both C and N can introduce spin-splitting defect states in the band gap. It is shown that a single C (or N) atom can produce a magnetic moment of 1.99 μ B (or 0.99 μ B) on the surface. In addition to the local magnetic moment on the dopant atom, many spins are distributed in the crystal gap. Calculations with the generalized gradient approximation with Coulomb repulsion U show that Co (or Ni) can produce a magnetic moment of 1.0 μ B (or 2.0 μ B) in the system, but the spin polarization occurs mainly in the valence band. Studies on magnetic coupling between dopant atoms at different distances show that only Co–Co exhibits mainly ferromagnetic coupling, while C–C, N–N, and Ni–Ni are dominated by antiferromagnetic coupling. Therefore, doping with Co can produce a relatively stable macroscopic magnetism. [Display omitted] • Oxygen vacancy cannot produce d 0 ferromagnetism on the SnO 2 (001) surface. • Both C and N can produce spin splits in the band gap on the surface. • The spin polarization caused by the Co (or Ni) atom occurs in the valence band. • Only Co–Co at different distances exhibits mainly ferromagnetic coupling. [ABSTRACT FROM AUTHOR]

A first-principles theoretical study of the enhanced electronic and magnetic properties of a single-layer CdS (denoted as SL-CdS) was conducted via Li substitutional doping at possible sites. Previous work shows that SL-CdS is a non-magnetic and direct bandgap semiconductor. Our work demonstrated that electronic bandgap tuned to smaller and larger values, e.g., the calculated bandgap (pseudo bandgap) for Li Cd (Li h) are 1.80 eV and 1.62 eV, respectively. Local magnetic moment induced via Li atomic doping at possible dopants sites except for Li h. The Li Cd gives a maximum magnetic moment of 0.98 μ B and shows the half-metallic character with a small dispersion for the spin-down channel at the Γ point. Among all the possible sites, the Li Cd in SL-CdS is magnetic and being most favorable thermodynamically under both S-rich and Cd-rich conditions. The Li Cd in SL-CdS indicates spin polarization with increased bandgap for spin-up and spin-down channels. In contrast, the Li S induces a magnetic moment of 0.86 μ B with a reduced bandgap of 0.60 eV for both the spin-up and spin-down channels. The partial magnetic moment is due to the fact small concentration of the dopant. Interestingly, Li h in SL-CdS shows non-magnetic semiconducting nature with decreased bandgap. For further investigation, we considered the most favorable Cd-Site. For room-temperature ferromagnetism, we did ferromagnetic and anti-ferromagnetic calculations. We considered interactions between two Li atoms substituted at far positions (1, 2) and near positions (1, 3) in SL-CdS. It was found that 2Li Cd in SL-CdS at near positions (1, 3) has FM order with Curie temperature (T c) of 339.95 K at − 5 % compressive biaxial strain. The effect of Li doping on electronic and magnetic properties of SL-CdS can help to utilize SL-CdS materials in electronics and spintronics devices applications. • We select nitrogen (Li) as a first-row element that could host spin-polarized electrons in its s-orbitals as possible sources of magnetic moment, and study various possible dopant positions. • The main aims of our study are (i) tuning of the electronic bandgap (ii) inducing magnetic moments in diamagnetic single-layer CdS. • Studying ferromagnetic (FM) and antiferromagnetic (AFM) coupling to predict the more favorable state. • Our material shows three simultaneous properties of ferromagnetism, diamagnetism and semiconducting one. • To the best of our knowledge, no 2D material is predicted to have such high temperature stability of these properties to-date. [ABSTRACT FROM AUTHOR]