Preparation and characterization of B-C-N nanotubes by a rapid quenching method

B-C-N nanotubes prepared by a plasma evaporation method were characterized by a transmission-electron microscopy (TEM) and an electron-energy-loss spectroscopy (EELS). The nanotubes obtained were divided into three types of carbon-, boron nitride-, and combined nanotubes of boron nitride with carbon. However, BC_xN nanotubes of homogeneous phase could not be obtained. This indicated that a stable phase in the experimental condition was in the mixtures of carbon and boron nitride rather than in a homogeneous phase of BC_xN compounds. Also the effect of temperatures on the formation of nanotubes was studied. Resultantly it was shown that nanotubes were formed at higher temperatures than 3000 K and, on the other hand, nanocapsules were formed at lower temperatures than 3000 K. Based on the microstructural data obtained, the formation mechanisms of both nanotubes and nanocapsules were described.