substrates were dipped into solutions of Fe and Co chloride dissolved in ethanol (experimental details in the Methods section) and CVD growth was performed under isothermal and nonisothermal conditions similar to those described above. The non-isothermal growth from metal salts also exhibited a higher yield of CNTs compared to isothermal growth from both Co and Fe catalysts (SEM images in Figure ). Raman spectral analysis of the RBM frequencies (Figure showed similar results to those presented in Figure corresponding to the 0.3 nm-thick Co catalyst films, i.e. the CNT diameters in the non-isothermal growth from metal salts were similar to the isothermal growth at lower temperature (750 ºC).