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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]

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]

Effect of Cr doping on the magnetic structure and electronic properties of Fe 2 VSi has been investigated by experimental measurement and first-principles calculations. In Fe 2 V 1-x Cr x Si, ferromagnetism can be stabilized with 10% Cr substitution. The Curie temperature T C increases rapidly with increasing Cr content and reaches 365K when x = 0.4. The saturation magnetization M s also increases with increasing Cr content. A small amount of A15 secondary phase is observed with increasing Cr content at x = 0.4, indicating that the solid solubility of Cr in Fe 2 VSi has been reached. In Fe 2 V 1-x Cr x Si, high spin polarization ratio is predicted when x ≥ 0.25, and half-metallic character is observed when x = 0.5, 0.75 and 1.0. The calculated total spin moment M t also increases with increasing x. When x is larger than 0.2/0.25, the experimental/theoretical total moment gets close to the Slater-Pauling curve of M = Z - 24 for half-metallic Heusler alloys. All this makes Fe 2 V 1-x Cr x Si promising candidates for spintronic applications. [ABSTRACT FROM AUTHOR]

Ferromagnetism in half-metallic two-dimensional material can lead to unique spintronics application. In this work, Cr-doped single-layer graphdiyne is predicted to be two-dimensional ferromagnetic semiconductor, and Mn-doped graphdiyne is predicted to be ferromagnetic conductor using first-principle calculations. Cr and Mn adatoms could be stabilized on the corner sites of graphdiyne sheet due to high migration barriers. The currents through Cr- and Mn-doped graphdiyne possess spin polarization feature. For Cr-doped graphdiyne system, the transmission polarization is up to 100% and could be controlled by the gate voltage. Cr-/Mn-doped graphdiyne with spin-polarized semiconductor/conductor properties could be promising material for combined usage in spintronics application. [ABSTRACT FROM AUTHOR]

The electronic structure and magnetism properties of V-doped monolayer MoS 2 under biaxial strains were researched through the first-principle calculations. The V-doped MoS 2 is a p-type semimetal with ferromagnetism (FM) state at zero strain, of which V–MoS 2 and V atom exhibit the magnetic moment of 0.81 and 0.30 μ Β , respectively. However, as the biaxial tensile strain is applied and increased gradually, the ground state changes from ferromagnetism (FM) to anti-ferromagnetism (AFM) and the magnetic moment simultaneously reduces. When the biaxial tensile strain is 3%, the ground state of the system turns into the AFM state. Moreover, under biaxial compressive strain, the system also changes from ferromagnetism (FM) to anti-ferromagnetism (AFM). The magnetism and stability of the FM state are weakened gradually due to the strengthened ionic characteristics of Mo–S bonds and the non-localization d orbitals of Mo and V atoms. The results provide a path to adjust the electronic states and magnetism characteristics of 2D transition metal dichalcogenides (TMDs), paving the way for application in spintronic devices. Slight doping with V leads to spin polarization which weakens and even disappears at large tensile strain depending on the increased ionic character of Mo and S bonds and resultant delocalization of Mo d orbitals. Image 1 • FM features of V-doped monolayer MoS 2 are weakened under tensile strain. • V-doped monolayer MoS 2 is changed into AFM state at the biaxial tensile strain of 3%. • The FM stability is lowered and even disappears because of the increased ionic character of Mo and S bonds and resultant delocalization of Mo d orbitals. [ABSTRACT FROM AUTHOR]