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在化学气相沉积法(CVD)制备洋葱状富勒烯(OLFs)过程中,温度是最主要的参数之一。以烃类为碳源,二茂铁为催化剂,在不同温度下制备OLFs,分析了温度对形成机理的影响,通过场发射扫描电镜(FESEM)对产物的形貌和微观结构进行了表征。采用热重(TGA)考察了OLFs的热稳定性,表明温度越高,形核所需的最大吉布斯自由能越小,越容易形核,形成的晶核越稳定。当温度超过1000℃时,晶粒之间的融合能力也随之增强,产物出现粘连现象,从而1000℃为制备OLFs的最佳温度。
During the preparation of onion-like fullerenes (OLFs) by chemical vapor deposition (CVD), temperature is one of the most important parameters. The effects of temperature on the formation mechanism were analyzed by using hydrocarbon as carbon source and ferrocene as catalyst to prepare OLFs at different temperatures. The morphology and microstructure of the products were characterized by field emission scanning electron microscopy (FESEM). The thermogravimetry (TGA) was used to investigate the thermal stability of OLFs. The higher the temperature, the smaller the Gibbs free energy required for nucleation, the easier nucleation. The more stable the nuclei formed. When the temperature exceeds 1000 ℃, the fusion ability between the grains also increases, the product appears blocking phenomenon, so 1000 ℃ is the best temperature for the preparation of OLFs.