Figure 4
From: Dual growth mode of boron nitride nanotubes in high temperature pressure laser ablation
Schematic of (a) root growth and (b) open-end growth processes. (a) In root growth, a BN nanotube evolved from pre-formed BN cap on the surface of boron nanodroplets. Tube growth was sustained by the supply of nitrogen atoms at the root of the tubular structure. At the end of the process, BNNTs would have the NP1 end or open end if boron nanodroplets were completely consumed. (b) Open-end growth, on the other hand, started from polygonized h-BN layers formed from the nucleation of physisorbed BN radicals. Boron nanodroplets were kept isolated during the growth process, and the growth was maintained by the physisorption of BN radicals at the open end.
