Covalent-bonded graphyne polymers with high hardness
Covalent-bonded graphyne polymers with high hardness
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DOI：
10.3103/s1063457614040042
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发表时间：
2014-08
影响因子：
0.9
通讯作者：
Meng Hu;Julong He;Qianqian Wang;Quan Huang;D. Yu;Yongjun Tian;Bo Xu
中科院分区：
文献类型：
--
作者：
Meng Hu;Julong He;Qianqian Wang;Quan Huang;D. Yu;Yongjun Tian;Bo Xu
基于第一性原理的USPEX和CALYPSO方法，提出了八种共价键合的石墨炔聚合物。这些聚合物在环境压力下比相应的石墨炔在能量上更有利，其中七个比富勒烯C60更稳定，表明它们存在的可能性。这些晶体结构的力学和动力学稳定性已被证实，通过计算它们的弹性常数和声子色散曲线，分别。最新开发的可变单元轻推弹性带（VC-NEB）模拟表明，石墨炔→聚合物转变比石墨→金刚石转变具有更低的能垒。已经发现两种石墨炔聚合物是超硬的，并且其他的是硬材料。这些石墨炔聚合物具有从金属到金属的可调电子特性。
Eight covalent-bonded graphyne polymers have been proposed using the newly developed USPEX and CALYPSO methods based on the first-principle calculations. These polymers are energetically more favorable than the corresponding graphyne under ambient pressure, and seven of them are more stable than fullerene C60, indicating their existence possibilities. The mechanical and dynamic stabilities of these crystal structures have been confirmed by calculating their elastic constants and phonon dispersion curves, respectively. The newly developed variable-cell nudged elastic band (VC-NEB) simulations show that the graphyne → polymer transformation exhibits lower energy barrier than the graphite → diamond transformation. Two of the graphyne polymers have been found to be superhard, and the others are hard materials. These graphyne polymers possess tunable electronic properties from metallic to semiconductive.