Many of the properties of SiC are decided by the polytype. In the present work, the effect of the reaction path on the SiC polytype is studied. Two kinds of SiC particles were prepared at 820 °C in an Al–Si–C system. Results show that 6H-SiC with a hexagonal structure and 3C-SiC with a face-centered cubic structure were obtained separately with a liquid–solid reaction and master alloy method. Further research revealed that 6H-SiC was formed via a one-step reaction with graphite as the precursor, while 3C-SiC was synthesized via a two-step reaction with Al₄C₃ as the intermediate product and precursor. A different reaction path and precursors result in a different growth process. 6H-SiC was grown under a polynuclear multilayer growth mechanism, while 3C-SiC was grown by a multiregion transition of Al₄C₃.

中文翻译：

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820°C的Al–Si–C系统中6H-SiC和3C-SiC的合成和生长：反应路径对SiC多晶型的影响

SiC的许多特性取决于多型性。在目前的工作中，研究了反应路径对SiC多晶型的影响。在Al–Si–C系统中，在820°C下制备了两种SiC颗粒。结果表明，通过液固反应和中间合金法分别获得了具有六方结构的6H-SiC和具有面心立方结构的3C-SiC。进一步的研究表明，以石墨为前驱物通过一步反应形成6H-SiC，而通过Al ₄ C ₃进行两步反应合成3C-SiC。作为中间产物和前体。不同的反应路径和前驱物导致不同的生长过程。6H-SiC是在多核多层生长机制下生长的，而3C-SiC是通过Al ₄ C ₃的多区域转变生长的。