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To meet the current requirements of diluted magnetic semiconductors (DMSs) resulting from continuous advancements in spintronics, designing d0 DMSs with high stability, spin polarization, and Curie temperature is essential. Present research on introducing d0 magnetism is limited to monatomic doping, lacking regulation measures for local magnetic moments and long range magnetic coupling. Herein, an adjacent doping strategy is employed to introduce degrees of freedom for tuning the magnetic properties of d0 DMSs. It is observed that by introducing Si and O atoms as central and adjacent dopants, respectively, the intrinsically nonmagnetic hexagonal boron nitride (h-BN) exhibits significant local magnetic moments. Furthermore, it is observed that the ionization energy, total magnetic moment, magnetic coupling, and Curie temperature of the doped h-BN are susceptible to the Si–O coordination. Subsequently, a magnetic half-metal (Si–O3-doped h-BN) with high thermal stability, 100% spin polarization, long range ferromagnetic coupling, and high Curie temperature is designed through high Si–O coordination doping. This study proposes a feasible approach for introducing tunable d0 magnetism using the design of Si–O adjacent-doped h-BN as an example. [ABSTRACT FROM AUTHOR]

We report first-principles investigation on structural, electronic and magnetic properties of 3d transition metal element-doped rock-salt calcium selenide Ca 1 − x TMxSe (TM = V, Cr and Mn) at concentrations x = 0.0625, 0.125 and 0.25. We performed the calculations in the framework of the density functional theory (DFT) using the full-potential linearized augmented plane waves plus local orbitals (FP-LAPW+lo) method within the Wu–Cohen generalized gradient approximation (WC-GGA) for the structural optimization and the Tran–Blaha modified Becke–Johnson (TBmBJ) potential for the electronic and the magnetic properties. The computed spin-polarized band structures and densities of states show that Ca 1 − x CrxSe compounds at all studied concentrations are half-metallic ferromagnets with a complete spin polarization of 100% at Fermi-level while the Ca 1 − x VxSe and Ca 1 − x MnxSe are ferromagnetic semiconductors. The total magnetic moments for Ca 1 − x VxSe, Ca 1 − x CrxSe, and Ca 1 − x MnxSe show the integer values of 3 μ B , 4 μ B , and 5 μ B , respectively, with a major contribution of transition metal elements (TM) in the total magnetization. Also, we reported the calculated exchange constants N 0 α and N 0 β and the band edge spin splitting of the valence (Δ E v ) and conduction (Δ E c ) bands. The ferromagnetism of these compounds is due to the super-exchange and the double-exchange mechanisms in addition to the strong p–d exchange interaction. Therefore, the predicted results indicate that the diluted Ca 1 − x TMxSe (TM = V, Cr, Mn) compounds are suitable candidates for a possible application in the field of spintronic technology. [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]

This study focuses on new diluted magnetic semiconductors that have good characteristics. The chemical compound we use in this paper is Mg 1-x Cr x S (x = 0,0, 0.125, 0.25, 0.50, 0.75) at the ferromagnetic rock salt phase, We used the linearized augmented plane wave method implemented in the wien2k package to simulate compound properties and adopted the WC-GGA approximation to calculate structural and elastic properties and the Tb-mBJ approximation (Tran-Blaha modified Becke-Johnson potential) to calculate electronic, and optical properties. The results obtained prove that the ferromagnetic (FM) phase is more stable than the antiferromagnetic (AFM) and nonmagnetic (NM) phases, the energy band of all ternary compounds Mg 1-x Cr x S has been shown to be half-metals with a 100% spin polarization at the Fermi level (E F) and total magnetic moment values equal to 4 μB. The study reported that the elastic properties of Mg 1-x Cr x S (x = 0.125, 0.25, 0.50, 0.75) compounds are mechanically stable with high mechanical anisotropy. The optical spectra of ternary compounds Mg 1-x Cr x S (x = 0.125, 0.25, 0.50, 0.75) are distinguished from those of MgS by the appearance of additional absorption at low energy. The compounds are dispersive media that show strong absorption in the ultraviolet radiation region observed on the α (ω) curve. [ABSTRACT FROM AUTHOR]

Spin polarized van der Waals (vdW) heterostructures have attracted considerable interest owing to the spin splitting manipulation. In this paper, first-principles calculations are employed to explore the two-dimensional arsenene/CrI 3 vdW heterostructure as a promising spin polarized material, as well as the spin polarization under strain and electronic field are investigated. The most stable stacking configuration and ferromagnetic (FM) property of the arsenene/CrI 3 vdW heterostructure have been confirmed. The detailed calculations show that the Curie temperature (T c) of the FM coupling CrI 3 layer in the heterostructure can be enhanced up to 61 K, which is attributed to both superexchange interaction and proximity exchange effect. The electronic structures suggest that this heterostructure possess an intrinsic type-II band alignment and diluted magnetic semiconductor property. Interestingly, we found a transition from diluted magnetic semiconductor to half-metal and gradually to metal induced by the biaxial strains, and the extra electronic field can modulate the "maxican hat" of the valance band maximum (VBM) of arsenene. Our work provides not only application prospects of the arsenene/CrI 3 vdW heterostructure nanodevices but also theoretical effective support for the research and development of the spin electronics and flexible electronics. • The arsenene/CrI 3 heterostructure possess an intrinsic type-II band alignment and diluted magnetic semiconductor property. • Biaxial strains can make arsenene/CrI 3 heterostructure transform from diluted magnetic semiconductor to half-metal and gradually to metal. • Electronic field can change the contribution of As and I atoms in VBM, enlarge the band gap. [ABSTRACT FROM AUTHOR]

In the present work, theoretical investigations of structural, electronic, magnetic, and thermoelectric properties of Cd 0.875 TM 0.125 O (TM = Mn, Fe, Co, Ni) half-metallic ferromagnets are done using WIEN2K code. The computed results when compared with the reported theoretical works reveal consistency. The band structures for spin up (↑), and spin down (↓) channels reveal the half metallic (Mn, Co, Fe), and frustrated (Ni) magnetism. The nature of magnetism has been analyzed in terms of hybridization among 3d states of TMs, individual Cd (5s, 4d) states, and O (2p) states. The control and function of the electron spin are revealed by calculating exchange energies (Δ x (d), Δ x (pd)), crystal field energy (ΔE cryst) and exchange constant (N o α, N o β), those play a very crucial role in understanding the magnetic nature. Moreover, double exchange and RKKY models are discussed to justify the observed half-metallic, and metallic behaviors, which are responsible for the magnetic moments to stabilize a magnetic polarization. The influence of electron spin is explained using the computed electrical and thermal conductivities, while thermoelectric power is elaborated by computing Seebeck coefficient and power factor. • Above room temperature ferromagnetism, and spintronic applications •Quantum spin of electrons dominant the charge with multifuctional properties •Exchange mechanism certifies the ferromagnetism by electron spin instead of magnetic ion clustering •Half metallic ferromagnetism and 100% spin polarization •Large value of electrical conductivity and ultralow low values of thermal conductivity. [ABSTRACT FROM AUTHOR]