Research Highlight

Nanotubes wear magnetic cloak

doi:10.1038/nindia.2010.0 Published online 19 January 2010

Researchers have modified nanotubes into devices with better field emission that promise to revolutionise single and multiple electron beam devices.

They have designed metallic magnetic nanomaterials encapsulated multi-walled carbon nanotubes (MWNTs).

MWNTs are reported to be excellent field emitters with low turn-on (voltage) fields. Changes can be induced in the field emission by decorating the surface of carbon nanotubes with different nanoparticles.

The researchers tapped the potential of magnetic nanoparticles (nickel and iron) to modify the surface of MWNTs with catalytic chemical vapour decomposition method.

The metal-encapsulated MWNTs exhibited superior field emission performance than pure MWNT-based field emitters over the same substrate. The results indicate that a nickel-filled MWNT field emitter is a promising material for practical field emission application with a lowest turn-on field and a high emission current density.

The authors of this work are from: Department of Physics, Indian Institute of Technology Madras, Chennai, India and Department of Physics, Faculty of Science, National University of Singapore, Singapore.


  1. Rakhi, B. R. et al. Electron field emission from magnetic nanomaterial encapsulated multi-walled carbon nanotubes. Appl. Phys. Mater. Sci. Process. 98, 195-202 (2010) | Article