Research Article

Nano Research

, Volume 1, Issue 5, pp 420-426

Open Access This content is freely available online to anyone, anywhere at any time.

Enhanced ferromagnetism in ZnO nanoribbons and clusters passivated with sulfur

  • Andrés R. Botello-MéndezAffiliated withNational Laboratory for Nanoscience and Nanotechnology Research (LINAN), Advanced Materials Department, IPICYT
  • , Florentino López-UríasAffiliated withNational Laboratory for Nanoscience and Nanotechnology Research (LINAN), Advanced Materials Department, IPICYT
  • , Mauricio TerronesAffiliated withNational Laboratory for Nanoscience and Nanotechnology Research (LINAN), Advanced Materials Department, IPICYT Email author 
  • , Humberto TerronesAffiliated withNational Laboratory for Nanoscience and Nanotechnology Research (LINAN), Advanced Materials Department, IPICYT

Abstract

Inspired by recent experimental results, the electronic and magnetic properties of sulfur-passivated ZnO clusters and zigzag nanoribbons have been studied using first principles calculations in the framework of the local spin density approximation. In the case of the ZnO nanoribbons, the sulfur atoms or thiol groups were attached in different ways to the zinc or oxygen atoms located at the edges, whereas in clusters, the sulfur atoms were set on the surface, mainly interacting with atoms with low-coordinate number. After an exhaustive atomic relaxation, we found that a magnetic moment emerges in zigzag nanoribbons both with and without sulfur-passivation on the edges. However, the magnitude of the magnetic moment is very sensitive to sulfur passivation. In particular, we found that when sulfur is attached to the zinc atoms in an alternating fashion along the ribbon edges, the magnetic moment is a maximum (1.4 µB/unit cell). In the case of clusters, we found that the Zn15O15 cluster exhibits a high spin moment of 5.5 µB when capped with sulfur atoms. Our calculations indicate that sulfur-passivating of ZnO nanosystems could be responsible for recently observed ferromagnetic responses.

http://static-content.springer.com/image/art%3A10.1007%2Fs12274-008-8042-3/MediaObjects/12274_2008_8042_Fig1_HTML.jpg

Keywords

Zinc oxide sulfur magnetism nanoribbons clusters