Abstract
A large-scale production of necklace-like SiC/SiO&sub2; heterojunctions was obtained by a molten salt-mediated chemical vapor reaction technique without a metallic catalyst or flowing gas. The effect of the firing temperature on the evolution of the phase composition, microstructure, and morphology of the SiC/SiO&sub2; heterojunctions was studied. The necklace-like SiC/SiO&sub2; nanochains, several centimeters in length, were composed of SiC/SiO&sub2; core-shell chains and amorphous SiO&sub2; beans. The morphologies of the as-prepared products could be tuned by adjusting the firing temperature. In fact, the diameter of the SiO&sub2; beans decreased, whereas the diameter of the SiC fibers and the thickness of the SiO&sub2; shell increased as the temperature increased. The growth mechanism of the necklace-like structure was controlled by the vapor-solid growth procedure and the modulation procedure via a molten salt-mediated chemical vapor reaction process.