Two-Dimensional Be2C with Octacoordinate Carbons and Negative Poisson's Ratio
Two-Dimensional Be2C with Octacoordinate Carbons and Negative Poisson's Ratio
复制标题
具有八配位碳和负泊松比的二维 Be2C
DOI：
10.1021/acs.jpcc.7b12758
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发表时间：
2018-04-12
影响因子：
3.7
通讯作者：
Huang, Wuying
中科院分区：
文献类型：
--
作者：
Qian, Shifeng;Sheng, Xiaowei;Huang, Wuying
在这项工作中，我们预测了三个新的二维（2D）Be 2C结构，即α-Be 2C，β-Be 2C，和γ-Be 2C，密度泛函理论（DFT）计算的基础上，粒子群优化（PSO）方法。在α-Be 2C中，一个碳原子与八个Be原子结合，形成八配位碳部分。这是含八配位碳材料的第一个例子。另外两种结构，β-Be 2 C和γ-Be 2 C，是含有准平面六配位碳（phC）的二维材料。较低的内聚能和正的声子模揭示了这三个相的良好稳定性。更有趣的是，这些预测的Be 2 C的新阶段都是半导体，并具有不寻常的负泊松比（NPR）。如果合成，2D Be 2C材料将在电子和机械方面具有广泛的应用。
In this work, we predicted three new two-dimensional (2D) Be2C structures, namely, alpha-Be2C, beta-Be2C, and gamma-Be2C, on the basis of density functional theory (DFT) computations and the particle-swarm optimization (PSO) method. In alpha-Be2C, a carbon atom binds to eight Be atoms, forming an octacoordinate carbon moiety. This is the first example of an octacoordinate carbon containing material. The other two structures, beta-Be2C and gamma-Be2C, are quasi planar hexacoordinate carbon (phC) containing 2D materials. Good stability with these three phases is revealed by their lower cohesive energy and positive phonon modes. More interestingly, these predicted new phases of Be2C are all semiconductors and have unusual negative Poisson's ratios (NPRs). If synthesized, 2D Be2C materials will have a broad range of applications in electronics and mechanics.