Chemistry Reference
In-Depth Information
(Si(CH
3
)
3
Cl),
methytrichlorosilane (MTS), propane (C
3
H
8
),
as precursors and
different metals as a catalyst (Attolini et al.
2014
).
Carbothermal reduction involves a mixture of powders like WO
3
with graphite
(Park et al.
2004
), at high temperatures (1050-1100
â—¦
) the reaction produces carbon
monoxide (CO) which is carried by a carrier gas on the silicon substrate where it
forms silicon carbide in the presence of catalyst with silicon vapour.
If we use as the starting material a target made of SiC under the action of laser
(laser ablation), we have evaporation and condensation to form nanostructures on a
cold finger (Shi et al.
2000
).
Using arc discharge, it is possible to obtain SiC nanostructures with an hole anode
made in graphite with inside silicon carbide powder and pure graphite as cathode to
reach high temperature (Liu and Yao
2005
).
There are also techniques which are less used: combustion process (Huczko
et al.
2005
), polymer pyrolysis (Gao et al.
2008
) and microwave heating—assisted
method (Sundaresan et al.
2007
).
An interesting alternative method to obtain SiC nanowires is the surface conversion
of silicon NWs through a carbon treatment (called carburization) by using a carbon
source like propane or methane. The carburization process is similar to those in
preparation of SiC layers on silicon substrate (Zhang et al.
2000
; Xing et al.
2004
;
Ollivier
2013
; Latu-Romain et al.
2013
).
Instead of SiNWs, it is possible to use carbon nanotubes (CNTs) by reaction
with SiO or SiI
2
at high temperatures; transition occurs from CNTs to SiC NWs
(Iijima
1991
).
In literature, few publications occurs for the preparation of hexagonal SiC
nanowires and are mainly related to 6H orientation.
The most important methods are polymer pyrolysis (Gao et al.
2008
), arc-
discharge procedure (Li et al.
2002
) and microwave process (Wei et al.
2008
).
The T-D method is not so common but SiCNWs with a diameter of 55 nm were
fabricated by means of etching from 3C-SiC layers grown on silicon substrates with
a thickness of 50 nm (Feng et al.
2010
).
It is interesting to list the possible potential applications of silicon carbide
nanowires due to their chemical and physical properties:
filler, reinforcing element of ceramic matrix to increase the mechanical
performance
energy conversion
catalytic nanomaterials
hydrogen storage
field emission devices
coating
bio-applications
