Arc discharge technique

Langer et al. [10] measured also electrical resistance of individual MWCNTs at very low temperatures and in the presence of a transverse magnetic field. As for the case of the microbundle, the CNTs were synthesised using the standard carbon arc-discharge technique. Electrical gold contacts have been attached to the CNTs via local electron beam lithography with an STM. The measured individual MWCNT had a diameter of about 20 nm and a total length of the order of 1 im. 

Until recently, synthesis of nanostructured carbon materials was usually based on very harsh conditions such as electric arc discharge techniques [1], chemical vapor deposition [2], or catalytic pyrolysis of organic compounds [3]. In addition (excluding activated carbons), only little research has been done to synthesize and recognize the structure of carbon materials based on natural resources. This is somewhat hard to understand, as carbon structure synthesis has been practiced from the beginning of civilization on the base of biomass, with the petrochemical age only being a late deviation. A refined approach towards advanced carbon synthesis based on renewable resources would be significant, as the final products provide an important perspective for modern material systems and devices. 

Similar selective heating of the catalyst particles was observed by Harutyunyan [33] in the first step of a general purification procedure for single-wall CNT produced by the arc-discharge technique with an Ni-Y catalyst added to the electrodes. Microwave heating as an initial step for metal removal was compared with selective oxidation , which refers to selective oxidation of undesirable minority phases (Figs. 5.13 and 5.14). 

Soon after carbon nanotubes had been prepared by the arc discharge techniques [3], the suggestion was made that it might be possible to introduce metals into the inner core of the nanotubes. Such a proposal followed logically from the... 

Fig. 17. a TEM image showing single-walled nanotube bimdles, with encapsulated metal particles, produced by arc discharge techniques using Ni-Y/graphite mixtures scale bar 100 nm (courtesy of P.M. 

This section describes the production and characterisation of BN and B CyN nanostructures generated by arc discharge techniques and by pyrolysis of CHjCN-BClj over cobalt at 1000°C. The resulting graphite-like nanostructures show remarkable conducting and mechanical properties. 

Arc discharge technique This is similar to that used for fullerene synthesis, was applied for the preparation of carbon-encapsulated Ni, Co, or Fe nanoparticles. 

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