Computational Design of One‐Dimensional Ferromagnetic Semiconductors in Transition Metal Embedded Stannaspherene Nanowires

Abstract

of main observation and conclusion Developing low dimensional semiconductors with moderate band gaps, intrinsic ferromagnetism and large magnetic anisotropy energies (MAEs) is very desirable for high-speed nano-spintronic devices, which, however, still remains a big challenge. Here, via first principles calculations, a potential route to realize such materials is proposed based on a new class of one-dimensional transition metal (TM) embedded stannaspherene (Sn 12 2-) nanowires [TM 2 (Sn 12 )] ∞ (TM = Ti-Ni). Three semiconductors with robust ferromagnetism are achieved with TM = V, Cr and Fe, which all exhibit direct or quasi-direct band gaps around 1.0 eV, rendering their great potentials for visible light optoelectronic applications. Interestingly, [Cr 2 (Sn 12 )] ∞ and [Fe 2 (Sn 12 )] ∞ are both identified as bipolar magnetic semiconductors (BMS) with valence and conduction band edges spin polarized in the opposite directions, which are promising for realizing switch of carriers' spin orientation by electrical gating, while *V 2 (Sn 12 )] ∞ exhibits a half semiconductor (HSC) property with valence and conduction band edges spin polarized in the same direction and can be used for spin-polarized carriers generation. Moreover, sizable MAEs are discovered in these nanowires, which are at least two orders of magnitude larger than those of Fe, Co and Ni bulks and also significantly larger than current ferromagnetic semiconductors.www.cjc.wiley-vch.de

Endohedrally Doped Cage Clusters

“…The dynamic stability of this nanowire is further assessed by frequency analysis and AIMD simulations at 300 K. Further, the adsorption behaviors and electronic properties of NO, CO 2 , CH 4 , O 2 , H 2 , N 2 , and H 2 O molecules on the W@Au 12 based nanowire have been investigated. Most of the above gaseous molecules interact only weakly with the Very recently, Li and Yang 904 have designed a series of transition metal embedded stannaspherene nanowires using endohedrally doped M@Sn 12 (M = Ti−Ni) caged clusters as building units. In these novel nanowire structures, the M@Sn 12 cages are connected by additional M atoms as bridges, forming an infinite 1D chain of caged clusters.…”

“…Very recently, Li and Yang have designed a series of transition metal embedded stannaspherene nanowires using endohedrally doped M@Sn 12 (M = Ti–Ni) caged clusters as building units. In these novel nanowire structures, the M@Sn 12 cages are connected by additional M atoms as bridges, forming an infinite 1D chain of caged clusters.…”

Two-Dimensional Robust Ferromagnetic Semiconductors via Assembly of Magnetic Superatoms [Fe6S8(CN)6]5–

“…The spin-polarized band structures and density of states of 2D [NH 4 ] 3 [Fe 6 S 8 (CN) 6 ]­TM (TM = Cr, Mn, Fe, Co) systems at their FM ground states obtained with the HSE06 functional are presented in Figures and S6. In [NH 4 ] 3 [Fe 6 S 8 (CN) 6 ]­Cr (Figure S6a), the valence band maximum (VBM) state is completely spin-polarized in the spin-down direction, while the conduction band minimum (CBM) state is fully spin-polarized in the spin-up direction, making it a bipolar magnetic semiconductor (BMS). − For the other three systems with TM = Mn, Fe, and Co, the nanosheets change to be half semiconductors (HSC), exhibiting 100% spin polarization in the same orientation at both VBM and CBM. As an example, Figure a depicts a typical HSC band structure with a direct band gap of 1.96 eV for [NH 4 ] 3 [Fe 6 S 8 (CN) 6 ]­Fe.…”

Chemically Controlled Reversible Magnetic Phase Transition in Two-Dimensional Organometallic Lattices

“…In the aspect of the magnetic control method, the material’s spin orientation is tuned by reversing the direction of the applied magnetic field. , In the aspect of the electrical control method, the anisotropy of g tensors, spin–orbit coupling, or magnetoelectric coupling effect is utilized to realize the spatial rotation of spin under an electric field. Alternatively, we have previously proposed a conceptual material, called bipolar magnetic semiconductor, in which the carriers’ spin orientation can be controlled simply by applying a gate voltage. ,− In the aspect of the optical control method, laser-induced spin transformations including demagnetization, intralayer and interlayer spin transfer, and the antiferromagnetic (ferrimagnetic)–ferromagnetic transition have been achieved in rare earth orthoferrites, , metal alloys, , and magnetic multilayer composite systems. − In addition to magnetic, electrical, and optical control methods, other system-dependent control methods exist, such as the interfacial slip induced interlayer antiferromagnetic–ferromagnetic transition in Fe 3 GeTe 2 /CrI 3 and Fe 3 GeTe 2 /CrGeTe 3 ohmic contacts, the pressure-induced interchain ferromagnetic–antiferromagnetic transition in the CrSbS 3 monolayer, and the layer number induced interlayer and intralayer antiferromagnetic–ferromagnetic transition in CrTe 2 nanosheets …”