Preparation of nanosized silicon carbide powders by chemical vapor deposition at low temperatures

Abstract

Liquid carbosilane was synthesized and analyzed by infrared (IR) and H-NMR (nuclear magnetic resonance) spectroscopy. Silicon carbide (SiC) powders were prepared by chemical vapor deposition (CVD) at 850ºC and 900ºC from liquid carbosilanes. The product powders were characterized by IR spectroscopy, X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Results show that liquid carbosilane synthesized was the mixture of several oligomers that had a Si-C backbone. The powders prepared at 850ºC contain some organic segments, and those prepared at 900ºC are pure nanosized SiC powders, which are partly crystallized, the size of which is about 50–70 nm.