Catalyst‐Assisted Growth of Single‐Crystalline Hafnium Carbide Nanotubes by Chemical Vapor Deposition

Single‐crystalline hafnium carbide (HfC) nanotubes were synthesized by a one‐step catalyst‐assisted chemical vapor deposition (CVD) method. The typical nanotubes had uniform diameters of ~60 nm and wall thicknesses of ~15 nm and preferentially grew along 201]. From HRTEM/EELS analysis, the growth mechanism based on carbon nanotubes (CNT) tip growth and CNT‐templated reaction was proposed for explaining the formation of HfC nanotubes. According to the mechanism, CNTs were first formed by diffusion of C atoms on the surface of solid Ni catalyst particles. Then, gaseous Hf species reacted with C atoms from CNTs to form HfC nanotubes. During the entire growth process, Hf atoms did not participate in the catalytic reaction. Thus, this process was distinguished from the conventional vapor–liquid–solid process.