Pyrolytically grown arrays of highly aligned BxCyNz nanotubes

A pyrolysis route has been used to synthesize arrays of highly aligned ${\mathrm{B}}_x{\mathrm{C}}_y{\mathrm{N}}_z$ nanotubes in bulk. The structure and composition of the product were characterized by scanning electron microscopy, high-resolution transmission electron microscopy, and electron energy-loss spectroscopy. The length and diameter of the nanotubes are quite uniform in a large area of the reaction zone. The sizes of the aligned ${\mathrm{B}}_x{\mathrm{C}}_y{\mathrm{N}}_z$ nanotubes from the whole reaction zone are 10–30 μm in length and 20–140 nm in diameter. The $\mathrm{x/z}$ ratio of ${\mathrm{B}}_x{\mathrm{C}}_y{\mathrm{N}}_z$ nanotubes for most nanotubes is about 1:1. The $\mathrm{x/y}$ ratio of ${\mathrm{B}}_x{\mathrm{C}}_y{\mathrm{N}}_z$ nanotubes is up to 0.6. Within one nanotube, the $\mathrm{x/y}$ ratio is usually heterogeneous. The growth mechanism is also discussed.