Formation of nano-scale tubular structure of single crystal diamond

We report the first discovery of the vertically aligned nano-scale diamond tubes synthesized on a rugged polycrystalline diamond substrate. Each nano-scale diamond tube is typically 50-160 nm in size and is single crystalline with {111} twin defects inside. The aspect ratio of the nano-scale diamond tube can be fine-tuned by the applied bias voltage. The formation of single crystalline nano-scale diamond tubes can be well explained by the observed coalescence mechanism of diamond dots. (C) 2004 Elsevier B.V. All rights reserved.