Figure 3
From: Carbon nanotubes on nanoporous alumina: from surface mats to conformal pore filling
SEM images. (a) SEM image of the nanoporous alumina membrane (side and top view) before the nanotube growth. The membrane is formed by densely packed, highly ordered channels. (b, c) Low- and high-resolution SEM images of the membrane (top view) after the treatment by ‘900°C’ process, Fe only series, see Table 1. Only slight carbonous contaminations can be noted on the top of the membrane.