|
|
JMR Abstracts: September 1998
Article
Preparation of
<>b-SiC nanorods with and without
amorphous SiO2 wrapping
layersG.W. Meng*, L.D. Zhang*,
C.M. Mo+, S.Y. Zhang+, Y.
Qin*, S.P. Feng*, H.J.
Li#
(*Chinese Academy
of Sciences, +University of Science and Technology
of China, #Northwestern Polytechnical
University)
Preparation of
<>b-SiC nanorods with and without
amorphous SiO2 wrapping layers was achieved by
carbothermal reduction of sol-gel derived silica xerogels containing
carbon nanoparticles. The <>b-SiC
nanorods with amorphous SiO2 wrapping layers were
obtained by carboreduction at 1650°C for 1.5 hour, and at the end of 1.5 h
the temperature was steeply raised to 1800°C and held for 30 min. They are
typically up to 20 <>mm in length. The
diameters of the center thinner <>b-SiC
nanorods within the amorphous SiO2 wrapping layers
are in the range 10 ~ 30 nm, while the outer diameters of the
corresponding amorphous SiO2 wrapping layers are
between 20 and 70 nm. The <>b-SiC
nanorods without amorphous SiO2 wrapping layers
were produced by carbothermal reduction only at 1650°C for 2.5 hours;
their diameters are in agreement with those of the center thinner
<>b-SiC nanorods wrapped in amorphous
SiO2 layers. Large quantities of SiC rod nuclei
and the nanometer-sized nucleus sites on carbon nanoparticles are both
favorable to the formation of much thinner
<>b-SiC nanorods. The formation of the
outer amorphous SiO2 wrapping layer is from the
combination reaction of decomposed SiO vapor and
O2.
Order No.:
JA809-026 © 1998 MRS
Go to September 1998 Table of Contents
|
