Indium ion emission from nanotube fibres

The manufacture of a liquid metal ion source based on carbon nanotubes is described. Multi-wall carbon nanotubes were attached to the tip of a tungsten needle forming a fibre which was subsequently coated with a layer of indium. The onset of ion emission was observed at about 850 V, a value much lower than that for a conventional indium needle emitter. However, the nanotube fibres degrade rapidly at higher voltages and eventually disappear from the needle.