Large-area single-or multilayer graphene of high quality is synthesized on Ni films by radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) at a relatively low temperature (650℃).In the deposition process,a trace amount of CH4 gas (2-8 sccm (sccm denotes standard cubic centimeter per minute at STP)) is introduced into the PECVD chamber and only a short deposition time (30-60 s) is used.Single-or multilayer graphene is obtained because carbon atoms from the discharging CH4 diffuse into the Ni film and then segregate out at its surface.The layer number of the obtained graphene increases when the deposition time or CH4 gas flow rate is increased.This investigation shows that PECVD is a simple,low-cost,and effective technique to synthesize large-area single-or multilayer graphene,which has potential for application as electronic devices.
CNTs/TiH2 composite powders were prepared by plasma enhanced chemical vapor deposition （PECVD）. CNTs dispersed uniformly on the surface of Till2 particles and few defects were found in the tubular structure of the CNTs. According to DTA analysis, CNTs do not react with the base material Ti under 1 200 ~C. In order to investigate the application of CNTs/ Till2 powders in brazing, CNTs/TiH2 powders were mechanically mixed with Ni powders to develop a new type of brazing powder, and wetting experiments at 1 100 ~C showed a good wettability of CNTs/TiNi brazing powder.
In this paper, an approach to synthesizing carbon nanotubes （ CNTs ） reinforced A1-Si-Cu brazing powder was studied, which was accomplished by in-situ growth of the CNTs on the Al-Si-Cu powder at a relatively low temperature by plasma enhanced chemical vapor deposition （ PECVD ）. The synthesis parameters were optimized. The component of brazing powder was analyzed by X-ray diffraction （ XRD ）. The microstracture and dispersity of as-grown CNTs were investigated by scanning electron microscopy （SEM）. The graphitization and defects were characterized by Raman spectroscopy. The asgrown CNTs on Al-Si-Cu powder disperse uniformly and have moderate length and density, meanwhile its sp2 structure dominates minor quantity of amorphous carbons and defected carbon structures.
