Nitrogen Configuration in Individual CNx-SWNTs Synthesized by Laser Vaporization Technique

We present a new route to the synthesis of nitrogen doped single-walled nanotubes (CNx-SWNTs) based on laser vaporization technique. Using spatially resolved electron energy loss spectroscopy (SR-EELS), we measure the incorporation of nitrogen in SWNTs bundles as well as in individual tubes and investigate its atomic configuration in the graphitic network. Mean nitrogen content is estimated to be 1.7 atom %. A close inspection of the N-K absorption edge indicates that nitrogen atoms are rather in a pyridinic-like configuration than in graphitic substitution to carbon.