The Simulation Study Of Influence Factors Of Preparation SiC1D Nano Materials By CVD

In this paper, according to the space size and ventilation of self-designedcontrolled atmosphere furnace (ZL200510104486.4) for continuous preparing SiCnanowires, four different structure CVD reaction chamber were designed, and thetemperature field and flow field were simulated by means of Fluent software, a CVDreactor which is the most suitable for continuous preparing SiC nanowires wasselected, according to the best CVD reactor, we also simulated the influence rulewhich. These simulation results have been confirmed by experiments. In addition,according to the Cu, Fe, Ni and Pt metal catalyst which is the commonly used forpreparing SiC, we simulated the adsorption of SiO and C on the catalyst crystal face,and optimized the best catalyst for preparing SiC1D nano materials. The mainresults were as follows:First, four different structure CVD reaction chamber (“S” structure,“triangle”structure,“double triangle” structure,“回” structure) were designed, and thetemperature and gas flow field of the four reactors was simulated based on CFDprinciple by using Fluent software, the distribution cloud pictures of temperature andgas flow rate in every reaction chamber were obtained. By comparison we found thatthe temperature was lower near the hole in the four reaction chamber after reachingthe steady state, but the gas flow field simulation results show that the CVD reactionchamber of “回” structure was the best suited for continuous preparation of SiC NWs,because the gas flow was the most and the laminar flow area was the largest near thesubstrate surface, the area of Suitable for SiC NWs growth was the largest.Then, according to the “回” structure CVD reaction chamber, a Reasonablechemical model was established, and some reactions which involved in the processof preparation of SiC were simulated by means of Fluent software. The results showed that the temperature of the substrate where is close to the reactor hole waslower than that of other sites, and a large amount of turbulence existed at the upsideof the reactor hole, above factors rejected the growth of SiC NWs. In addition, thedistribution of each reaction gas component was also the main factor which makesmore SiC NWs deposite on the substrate centre. These simulation results have beenconfirmed by experiments.Finally, according to the Cu, Fe, Ni and Pt metal catalyst which is thecommonly used for preparing SiC, we simulated the adsorption of SiO and C on the(100),(110) and (111) of Cu, Fe, Ni, Pt based on DFT by means of Castap. Theresults showed that the SiO and C will priority adsorption on Cu (111), Fe (110), Ni(111) and Pt (111), because the energy of three crystal surface was the lowest andstablest. The more the adsorption energy of SiO on the catalyst, the amount of SiCwere the greater. Therefore, by comparison, the adsorption energy of SiO on thePt(111) is the greatest, and Pt is the best catalyst for preparing SiC1D nanomaterials.