Figure 1From: Effect of sulfur on enhancing nitrogen-doping and magnetic properties of carbon nanotubes SEM images of as-grown CNTs at three different temperatures with and without S. (a-c). Different temperatures with S: (a) 940°C, (b) 980°C, (c) 1020°C; (d-f) different temperatures without S: (d) 940°C, (e) 980°C, (f) 1020°C.Back to article page