Figure 4From: Flame synthesis of carbon nanostructures on Ni-plated hardmetal substrates The SEM morphologies of the carbon nanostructures deposited in different zones for different time lengths. The upper images are the center zone (a) and the marginal zone (b) of the 30-min sample, and the lower images are the center zone (c) and the marginal zone (d) of the 60-min sample.Back to article page