02243nas a2200217   4500008004100000022001400041245009100055210006900146260008000215300001400295490000700309520146900316100002101785700002001806700001701826700001301843700001801856700002201874700001601896856011301912       2006                        eng d  a0957-448400aEffect of a focusing electric field on the formation of arc generated carbon nanotubes0 aEffect of a focusing electric field on the formation of arc gene  aDIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLANDbIOP PUBLISHING LTDcDEC  a5895-59020 v173 a<p>The effect of a focusing electric field on the formation of carbon nanotubes in a direct current arc-plasma is investigated. The hard deposits on the surface of the cathode are the main products, rich in multi-walled carbon nanotubes. It is seen that the focusing electric field has a distinct influence on the yield, purity and morphology of the nanotubes. The yield of the carbon nanotubes under the `focused field condition' has been found to be higher than that derived from the normal electrode configuration. It has been observed that the deposition of carbonaceous soot on the reactor wall is considerably reduced on application of the focusing electric field. Transmission electron microscopy has been used to determine the morphology of the nanotubes. In addition, Raman spectroscopy has helped in distinguishing the graphene-like structures from the disordered carbon networks and helped in analysing the morphology of the tubes. Thermal analysis gave a qualitative estimation of the relative yield of carbon nanotubes within the cathode deposits and their thermal stabilities. The crystalline nature of the samples has been confirmed by x-ray diffraction analysis. The results clearly indicate that the focusing electric field confines the positively charged carbon precursors within the cathode-anode space causing high relative yield and purity and has a distinct effect on controlling the inner diameter of the as-synthesized carbon nanotubes.</p>1 aKarmakar, Soumen1 aNagar, Harshada1 aPasricha, R.1 aSeth, T.1 aSathe, V., G.1 aBhoraskar, S., V.1 aDas, A., K.  uhttps://library.ncl.res.in/content/effect-focusing-electric-field-formation-arc-generated-carbon-nanotubes-0