Video Clips

Field-Emission Induced Growth (FEIG) of nanowire

This video clip shows the growth of a tungsten nanowire in an SEM (Philips XL-30 ESEM FEG), using tungsten carbonyl as a precursor in the specimen chamber. Field emission is initiated by a tungsten tip (anode) touching the substrate (cathode) and breaking contact. The initiated tungsten nanowire then grows towards the anode as it is withdrawn from the surface. The SEM image is noisy due to electrons field-emitted from the tungsten nanowire resulting in random background noise. [Video credit: CH Oon]

Vibrating FEIG-grown Nanowire

A vertical tungsten nanowire was grown on an electrode (see above video) lying between two electrodes (lower part of image) to which a.c. voltages are applied. The frequency was tuned to the first-order resonance frequency of the nanowire. [Video credit: CH Oon]

Nanoparticle Nucleation & Growth on Carbon Nanotube

A multi-walled carbon nanotube (CNT) was contacted with a nanomanipulated tip in the SEM (Philips XL-30 ESEM FEG) and a current passed through the CNT to induce Joule heating. Decomposition of the precursor (tungsten carbonyl, cobalt carbonyl, etc.) occurs on the heated nanotube, resulting in nanoparticle nucleation and growth. [Video credit: SH Ong]

Evolution of Microstructure in Tungsten Nanowire (1)

A nanocrystalline tungsten nanowire (grown by FEIG) was heated in situ by Joule heating in the TEM (Philips CM-300). This video clip shows the later stages of evolution after grain growth to the stage of a bamboo structure has already taken place. The current through the nanowire was held constant. Grain grooves are seen to develop in video cip. [Video credit: GF You]

Evolution of Microstructure in Tungsten Nanowire (2)

Continuation of the above video some time later with more pronounced grain grooves having developed. Some smaller grains are seen to disappear as a result of diffusion to larger neighbouring grains. The nanowire eventually breaks. [Video credit: GF You]

Electromigration Failure in Tungsten Nanowire

Evolution of a void between two grains in a tungsten nanowire as a result of electromigration at high current density but relatively lower temperatures. Experiment conducted in situ in a Philips CM-300 TEM. [Video credit: GF You]

Field Emission Microscopy of Nanowire Field Emitter

FEM video showing emission from a nanowire tungsten field emitter. Adsorbates on the surface of the nanowire tip causes fluctuations in the emission and noise in the emitted current. [Video credit: KS Yeong]

Field Emission Microscopy of Nanowire Field Emitter

FEM video showing emission from a single-crystal ultra-thin (5nm) nanowire tungsten field emitter. The emitter is operating at relatively high temperatures resulting in very stable emission currents. Nonetheless, adsorbates on the surface of the nanowire tip are still seen to result in emission fluctuations. [Video credit: KS Yeong]

Field Emission Microscopy of ZnO Field Emitter

FEM video showing emission from a ZnO nanowire in an oxygen background. The emission pattern consists of randomly distributed and irregularly shaped emission spots. The relative brightness of the emission spots coincide with fluctuations in the emission current. The emission spots were likely to have originated from the surface adsorbates or clusters of surface atoms which dominate the FE process. [Video credit: KS Yeong]