A low-cost approach to fabricate SiC nanosheets by reactive sintering from Si powders and graphite

摘要

Silicon carbide (SiC) nanosheet with 2D micro-morphology was fabricated by reactive sintering method and a two-step sintering process. The effect of molar ratio of C and Si (from 1/1 to 4/1) on the phase composition and microstructure was investigated. The obtained results indicated that the SiC whiskers with an average diameter about 73.6 nm generated on the graphite substrate when the molar ratio of Si/C was 1 in the initial batch mixture. As a result of the molar ratio of Si/C at 3/1-4/1, the morphology of SiC generated in graphite surface changed from original whiskers to nanosheets structure. SiC nanosheets were obtained with the average thickness of 33.7 nm (standard deviation: 6.1) in the case of the sample containing Si/C molar ratios of 4/1. The TEM results proved that SiC nanosheets grown along [111] direction. The formation mechanism of SiC nanosheets has been explained in detail based on a liquid Si/graphite substrate model. (C) 2019 Elsevier B.V. All rights reserved.