Spontaneous curling of freestanding Janus monolayer transition-metal dichalcogenides
Spontaneous curling of freestanding Janus monolayer transition-metal dichalcogenides
复制标题
独立式Janus单层过渡金属二硫属化物的自发卷曲
DOI：
10.1039/c8cp02011f
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发表时间：
2018
影响因子：
3.3
通讯作者：
Li Zhen-huan
中科院分区：
文献类型：
--
作者：
Xiong Qi-lin;Zhou Jianli;Zhang Jin;Kitamura Takayuki;Li Zhen-huan
本文利用分子动力学模拟方法研究了独立Janus单层S-Mo-Se（MoSeS）结构的自发卷曲行为。利用密度泛函理论计算了Janus单层MoSeS的声子色散和声子谱，分析了其结构稳定性.结果表明，Janus单层MoSeS是结构稳定的。由于MoS和MoSe畴之间的晶格失配，处于独立状态的Janus单层MoSeS总是在恒定温度和压力系统中自发地卷起。卷曲的方向优选为沿着扶手椅取向。具体而言，对于Janus单分子层MoSeS，其尺寸大于30 nm，它可以自发地卷起成纳米管结构。利用经典的Kazhenko板理论和最小能量原理，揭示了这些现象的物理机制。
In this paper, using molecular dynamics simulations we report spontaneous curling behaviors of freestanding Janus monolayer S–Mo–Se (MoSeS) structures. Density functional theory calculations are performed to obtain the phonon dispersion and phonon spectra of the Janus monolayer MoSeS for analyzing its structural stability. The results show that the Janus monolayer MoSeS is structurally stable. Due to the lattice mismatch between MoS and MoSe domains, the Janus monolayer MoSeS at the freestanding state always spontaneously rolls up in a constant temperature and pressure system. The direction of curling is preferred along the armchair orientation. Specifically, as for the Janus monolayer MoSeS whose size is larger than ∼30 nm, it can spontaneously roll up into a nanotube structure. The underlying physical mechanisms of these phenomena are well uncovered by using classical Timoshenko plate theory and the minimum energy principle.