AbstractThis work is devoted to microwave heating of graphite, sucrose, calcined sucrose, and a mixture of graphite with sucrose to produce carbon nanotubes (CNT's). The samples were submitted to microwave radiation (power 800W, frequency 2.45 GHz) in air and high vacuum (10⁻⁵Torr) for 30 – 60 min. The oven temperature was approximately 1200°C. After vaporization the condensed material was collected on various fused silica targets (different morphologies were used). The samples were found to contain a significant proportion of nanotubes, nanoparticles and fibers (1-2.8 micrometers), which appeared to be highly graphitized and helical structured. After deposition, the morphology of carbon nanotubes was studied with SEM, TEM and AFM techniques. It was observed that multi-walled nanotubes (MWNT's) were produced by this method. The morphology of fused silicon based substrates (SiO₂, SiC) was studied as an important factor for the growth of carbon nanotubes. Many aspects as the size and shape of the obtained nanotubes on different substrates (porous and non-porous fused silicon substrates) were achieved, as well as the concentration of them across the substrate and other properties.