Inducing d 0 magnetism in new SrCl2 monolayer towards spintronic applications

Abstract

Magnetism engineering in two-dimensional (2D) materials has been widely explored to make new spintronic materials. In this work, the doping (with alkali metals at Sr sublattice and with chalcogen atoms at Cl sublattice) method are proposed to induce significant d 0 magnetism in the non-magnetic SrCl2 monolayer. This 2D material is an indirect gap insulator with large band gap of 4.97(6.25) eV as obtained by PBE(HSE06) functional, exhibiting ionic character that is generated by the charge transfer from Sr atom to Cl atoms. The monolayer is significantly magnetized by doping with alkali metals, where a total magnetic moments between 0.90 and 1.00 μ B are obtained. Herein, Cl atoms closest to the doping site make main contribution to the system magnetism. Interestingly, the doped systems exhibit half-metallic behavior that is generated by semiconductor spin-up state and metallic spin-down state. On the other hand, the diluted magnetic semiconductor nature emerges in SrCl2 monolayer as a result of doping with chalcogen atoms. In these cases, total magnetic moment of 1.00 μ B is obtained, where magnetic properties are produced mainly by chalcogen impurities and Cl atoms below them. The electronic and magnetic properties of the doped systems are regulated mainly by the outermost p orbital of Cl and chalcogen atoms, and Sr-4d orbital that form mainly the conduction band. Upon further increasing the doping level of K and O atoms, the half-metallic or magnetic semiconductor natures are preserved. Results presented in this work may introduce new prospective 2D spintronic candidates for spintronic applications, which are derived from a non-magnetic SrCl2 monolayer via doping with d 0 atoms.