Inhomogeneous strain-induced half-metallicity in bent zigzag graphene nanoribbons

Abstract

Realization of half-metallicity in low dimensional materials is a fundamental challenge for nano spintronics, which is a critical component for next-generation information technology. Using the method of generalized Bloch theorem, we show that an in-plane bending can induce inhomogeneous strains, which in turn lead to spin-splitting in zigzag graphene nanoribbons and results in the highly desired half-metallic state. Unlike the previously proposed scheme that requires unrealistically strong external electric fields, the obtained half-metallicity with sizeable half-metallic gap and high energetic stability of magnetic order of edge states requires only relatively low-level strain in the in-plane bending. Given the superior structural flexibility of graphene and the recent experimental advances in controllable synthesis of graphene nanoribbons, our design provides a hitherto most practical approach to the realization of half-metallicity in low dimensional systems. This work, thus paves a way towards the design of nanoscale spintronic devices through strain engineering.

Stable Nano‐Encapsulation of Lithium Through Seed‐Free Selective Deposition for High‐Performance Li Battery Anodes

“…As shown in Figure c 1,2 and Figure S19 (Supporting Information), the N‐HPCS undergoes an obvious size expansion upon lithiation, with its inner diameter increased from 260 to 268 nm, and the shell thickness from 26 to 35 nm. This indicates that the carbon shell has been sufficiently inserted with a considerable amount of Li . In contrast, lithiation of HPCSs and N‐HCSs causes no visible size increase or shell thickening before the deposition occurs, as revealed by a closer examination of these processes.…”

“…This indicates that the carbon shell has been sufficiently inserted with a considerable amount of Li. [20] In contrast, lithiation of HPCSs and N-HCSs causes no visible size increase or shell thickening before the deposition occurs, as revealed by a closer examination of these processes. In some cases, the seemingly shell thickening of these two nanospheres actually resulted from Li metal coating on its outside surface, rather than ion-insertion induced swelling ( Figures S20 and S21, Supporting Information).…”

Lattice dynamics of twisted ZnO nanowires under generalized Born–von Karman boundary conditions

“…However, standard methods encounter difficulties in dealing with crystals with screw and rotational symmetries. We indicate that this obstacle can be well overcome by a generalized Bloch scheme [39,40] that are formulated with these symmetry operations when solving electronic eigenvalue problem.…”

“…This way, the twist rate is obtained as | | g q = T 1 1 . For each considered twist rate, the NW is fully relaxed using the generalized Bloch theorem [39,40].…”

Fundamental Understanding of Nanostructured Si Electrodes: Preparation and Characterization

“…Red and green line: lithiation and delithiation of crystalline Si at room temperature, respectively . (b) Degradation mechanisms of large‐volume‐change anodes in LIBs . (I) Fracture and pulverization of high‐capacity electrode materials.…”