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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]

Using ab initio numerical results, we present a quantitative verification of the proposed contribution to the magnetic coupling in diluted magnetic semiconductors and transition metal oxides originated via successive spin polarizations over dopants and their first nearest neighboring (1nn) anion ligands. This is achieved through an examination of the variation with the magnetization density of both the magnetic moments of 3-d transition metal dopants and those of their 1nn anion ligands in various hosts. These results are then used to derive approximate exchange coupling constants assigned to the magnetic coupling between a dopant and its first nearest neighbor anion ligands for each host-dopant pair. This allows us to justify and/or predict the spin polarization state of an anion ligand which is common to two or three magnetic dopants and, in turn, to justify and/or predict the spin configuration and the intercoupling (ferromagnetic and/or antiferromagnetic) among the atoms of a cluster of dopants sharing common anion ligands. [ABSTRACT FROM AUTHOR]

• The proximity effect of graphene effectively improves the mobility and Curie temperature of the composite system. • There is a significant charge transfer at the interface between graphene and (V, N)ZnO. • The (V, N) doping pair on the surface of ZnO induces spin polarization of the graphene. Oxide-based diluted magnetic semiconductors usually exhibit above room-temperature ferromagnetism, but low carrier mobility limits their applications in novel spintronics. In this study, using first-principles calculation, the mobility, electronic and magnetic properties of V-N codoped ZnO((V, N)ZnO) system and its composite system (V, N)ZnO/graphene are studied. Compared with (V, N)ZnO, our results show that the electron mobility of the composite system is obviously increased by about three times (from 500 cm2 V−1 s−1 to 1500 cm2 V−1 s−1). In addition, we find that the ferromagnetism of the composite system is largely enhanced than that of the only V-N codoped ZnO. The Curie temperature of the composite system is estimated to be about 630 K based on the mean-field approximation theory, which is nearly twice as high as the (V, N)ZnO(321 K). This study provides effective theoretical guidance for improving carrier mobility and Curie temperature of oxide based dilute magnetic semiconductors. [ABSTRACT FROM AUTHOR]