First-principles investigation of dense B4C3
First-principles investigation of dense B4C3
复制标题
致密B4C3的第一性原理研究
DOI：
10.1021/jp074190c
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发表时间：
2007-09-20
影响因子：
3.7
通讯作者：
Tian, Yongjun
中科院分区：
文献类型：
--
作者：
Guo, Xiaoju;He, Julong;Tian, Yongjun
通过用B原子取代五个假设的致密C3 N4相中的N原子，建立了五个致密的B4 C3结构。晶格参数和弹性和电子性质的这五个B4 C3多晶型的第一性原理计算进行了研究。我们的计算表明，β-B4 C3是积极有利的相对于其他结构。赝立方B_4C_3是导电的，其他四种结构是导电的。用显微硬度模型计算了四种B_4C_3晶体的维氏硬度。发现这四种B4 C3多晶型物是超硬材料，硬度值高于55 GPa。B4 C3的立方相和立方尖晶石相都表现出更高的硬度，这与立方氮化硼的硬度相当。讨论了硬度与晶体结构的关系。
Five dense B4C3 structures are established via substitution of N atoms with B atoms in the five hypothetical dense C3N4 phases. Lattice parameters and elastic and electronic properties of these five B4C3 polymorphs are investigated by first-principles calculations. Our calculations show that β-B4C3 is energetically favorable relative to other structures. The pseudocubic B4C3 is conductive, and the other four structures are semiconductive. Vickers hardness of the four semiconductive B4C3 crystals is calculated using the microscopic model of hardness. These four B4C3 polymorphs are found to be superhard materials, with hardness values higher than 55 GPa. Both the cubic and the cubic spinel phases of B4C3 exhibit higher hardness, which is comparable with the hardness of cubic boron nitride. The relationship between hardness and crystal structure is also discussed.