Abstract
A mechanism for self-organization of C–B–N sandwich-like nanotubes with well-separated phases of C and BN [K. Suenaga, C. Colliex, N. Demoncy, A. Loiseau, H. Pascard, F. Willaime, Science 278, 653 (1997)] in arc-discharge is proposed. This mechanism includes (i) the microkinetic self-organization of nanotube growth in step-flow mode combined with a C and BN phase segregation at growth steps and (ii) the self-organization of “macro”-oscillations of impinging fluxes of C and B on the surface of nanotubes, which are caused by the nonuniformity of C and B content in the gas combined with the onset of natural convection, providing repeated transport of emerging nanotubes through regions with abundance in C and B, and leading to nucleation and growth of C and BN layers.