Crystalline silicon carbide nanocones and heterostructures induced by released iron nanoparticles

We present the formations of crystalline silicon carbide (SiC) nanocones and heterostructures catalyzed by iron nanoparticles, originally encapsulated in graphite-like carbon shells, via the vapor-liquid-solid process. We propose that the nanocone shape is due to the release of iron nanoparticles from their carbon shells followed by agglomeration, where the increasing size of the iron nanoparticle during SiC growth creates the nanocone shape. The release and agglomeration model may explain the formation of multisegmented SiC nanostructures. The encapsulation and controlled release of the metal catalyst is a promising method for the synthesis of unusual one-dimensional nanostructures and complex heterostructures.