Optical Studies of Single Walled Nanotubes Synthesized from C:BN:B4C Catalytic Mixture

Single-walled nanotubes have been synthesized by arc discharge technique from C:BN:B 4 C catalytic mixture with an admixture of a typical Ni:Y 2 O 3 catalyst. Nitrogen and helium have been used as ambient gases. The arc current and voltage were varied in the process. The synthesized materials have been characterized by a Raman spectroscopy. The arc current value increase induced a frequency shift of the dominating Raman radial breathing mode toward higher frequencies. This trend was opposite to that observed for the pure carbon nanotubes. A probability of doping and other mechanisms being able to result in such shift are discussed in this article.