Abstract
Realization of half-metallicity with a sizable minority-spin gap and ferromagnetic ordering has been a central research emphasis in the development of next-generation spintronic devices. To date, only three-dimensional half-metals have been achieved experimentally, while their counterparts based on two-dimensional (2D) materials remain to be materialized despite extensive efforts based on various predictive designs. This standing challenge is largely due to stringent requirements to establish ferromagnetic order in low-dimensional systems. Here we use first-principles approaches to show that atomically thin zigzag tungsten dichalcogenide (, Se) nanoribbons preserving the stoichiometry of stand as highly appealing intrinsic half-metallic systems, without invoking the prevailing approaches of applying an external electric field, chemical modification, or carrier doping. The readily accessible half-metallicity is attributed to distinctly different edge reconstructions, insulating along the X-terminated edges and metallic along the self-passivated W-terminated edges; the latter are further characterized by a robust spin-polarized electron transmission channel. These findings are expected to provide indispensable elemental building blocks for spintronic applications purely based on 2D materials.
1 More- Received 24 November 2018
- Revised 21 October 2019
DOI:https://doi.org/10.1103/PhysRevB.100.195304
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