在Si/C相位图中,不寻常的和预期的
Guoying Gao1, N W Ashcroft, Roald Hoffmann
1Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
Journal of the American Chemical Society
|July 12, 2013
概括
研究人员通过计算探索了碳化 (SiC) 结构. 他们发现了具有独特层次排列的新型变态稳定SiC3相,包括崩的石墨状结构和金属潜力.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学计算化学
- 固态物理 固态物理
背景情况:
- 在1 atm的-碳 (Si/C) 相位图中,主要显示稳定的碳化 (SiC) 多型.
- 由于动力因素而持久的转移稳定的Si/C相可以在各种组成中存在.
- 之前的假设表明,转移稳定相将局限于钻石状结构,特别是在Si3C等富含的化合物中.
研究的目的:
- 在Si/C相位图的富含碳的一侧以计算方式调查转移稳定的相位.
- 为了识别和表征新的动力学上持久的碳化结构,超出已知的稳定形式.
- 探索尚未探索的SiC石化物质的结构多样性和潜在特性.
主要方法:
- 计算机探索SiC3固体测量方法.
- 对潜在能量表面的分析,以确定超稳定的结构.
- 在新型SiC3相中对原子排列和结合的表征.
主要成果:
- 发现了不寻常的转移稳定的SiC3结构,挑战了先前的假设.
- 一个引人注目的崩塌的石墨状结构的识别,其中包括类C6单元和Si-Si桥梁.
- 观察其他具有聚和聚烯层的转移稳定结构,其中一些具有金属性质.
结论:
- /碳系统的富含碳的一面是意想不到的转移稳定阶段的所在地.
- 已识别的SiC3结构,包括与旋风相关的形式,扩展了已知的碳化结构景观.
- 一些新型的超稳定SiC3相具有潜在的有价值的电子性质,如金属性.
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