Magnetic Molybdenum Disulfide Nanosheet Films

Jia Zhang, Jia Mei Soon, Kian Ping Loh, Jianhua Yin, Jun Ding, Michael B. Sullivan and Ping Wu

Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Department of Material Science and Engineering, National University of Singapore, and Institute of High Performance Computing, Capricorn, Singapore Science Park II, Singapore 117528

Received 30 April 2007; revised 9 June 2007; published 17 July 2007

Nano Lett., 2007, 7, 2370-2376.

ABSTRACT:

Bulk molybdenum disulfide is known to be a nonmagnetic material. We have synthesized edge-oriented MoS2 nanosheet-like films that exhibit weak magnetism (~1-2 emu/g) and 2.5% magnetoresistance effects with a Curie temperature of 685 K. The magnetization is related to the presence of edge spins on the prismatic edges of the nanosheets. Spin-polarized calculations were performed on triangular-shaped cluster models in order to provide insight into the origin of magnetism on the edges as well as the size-property correlation in these MoS₂ nanosheets. Our results imply that nanostructured films with a high density of edge spins can give rise to magnetism even though the bulk material is nonmagnetic.

DOI: 10.1021/nl071016r