分子动力学模拟研究孪晶界对单层二硫化钼拉伸行为的影响
Molecular dynamics simulations for tensile behaviors of mono-layer MoS_2with twin boundary
查看参考文献36篇
|
文摘
|
孪晶界是单层过渡金属二硫族化物材料中的一种重要结构缺陷.本文通过分子动力学模拟结合Stillinger-Weber势函数研究单轴拉伸过程中孪晶界对单层MoS_2力学行为的影响.结果表明:1)孪晶界能够诱发裂纹在孪晶界附近形核,并促使裂纹沿界面扩展,从而降低晶体的断裂应变;2)温度的升高能够加剧孪晶界附近的裂纹形核过程,从而进一步减弱单层MoS_2的断裂强度和断裂应变;3)孔洞能够造成应力集中,从而进一步触发断裂过程,但孪晶界能够阻碍孔洞应力场的扩散,从而延缓单层MoS_2材料的断裂过程;4)孪晶片层间距对单层MoS_2断裂应变具有重要影响,特别是对于含孔洞的单层MoS_2材料,材料断裂应变能够随着片层间距的减小而显著提高. |
|
其他语种文摘
|
Grain boundary (GB) plays a key role in determining the electrical and mechanical properties of mono-layer transition metal dichalcogenide (TMDC), however it is still a challenge to uncover the GB-mediated TMDC material experimentally. In this paper, the effect of twin boundary on the tensile behaviors of mono-layer MoS_2is investigated by using the molecular dynamics simulation combined with the Stillinger-Weber potential. Mono-layer MoS_2model under the varied size and temperature condition is adopted. Stress calculation is performed by using Virial theorem. The results are obtained as follows. 1) Twin boundary promotes the brittle fracture of an undefected mono-layer MoS_2sheet by inducing the nucleation of the crack near boundaries, thus the fracture strength and strain are weakened. 2) Increasing the ambient temperature from 1 K to 600 K, the crack nucleation process near the twin boundary is intensely accelerated, and the fracture strength and strain are further declined. 3) Twin lamellar spacing also plays an important role in the tensile process of mono-layer MoS_2, and the specimen with dense twin boundary, especially with void, shows higher fracture strain. 4) Stress analysis at an atomic level outlines the stress concentration caused by voids and the shielding effect of twin boundary. Because of the interactions between voids and twin boundary, the fracture strength and strain of a voided mono-layer MoS_2sheet can be greatly improved. |
|
来源
|
物理学报
,2019,68(21):216201 【核心库】
|
|
DOI
|
10.7498/aps.68.20182125
|
|
关键词
|
单层二硫化钼
;
孪晶界
;
力学性能
;
分子动力学
|
|
地址
|
1.
辽宁工程技术大学应用物理与技术研究所, 葫芦岛, 125105
2.
辽宁工业大学理学院, 锦州, 121001
3.
东北大学材料科学与工程学院, 沈阳, 110819
|
|
语种
|
中文 |
|
文献类型
|
研究性论文 |
|
ISSN
|
1000-3290 |
|
学科
|
化学;晶体学 |
|
基金
|
国家自然科学基金
;
辽宁省自然科学基金
|
|
文献收藏号
|
CSCD:6625028
|
参考文献 共
36
共2页
|
|
1.
Novoselov K S.
Science,2004,306:666
|
CSCD被引
4144
次
|
|
|
|
|
2.
Geim A K.
Nat. Mater,2007,6:183
|
CSCD被引
2341
次
|
|
|
|
|
3.
Radisavljevic B.
Nat. Nanotech,2011,6:147
|
CSCD被引
782
次
|
|
|
|
|
4.
Wang Q H.
Nat. Nanotech,2012,7:699
|
CSCD被引
771
次
|
|
|
|
|
5.
Yin X B.
Science,2014,344:488
|
CSCD被引
49
次
|
|
|
|
|
6.
魏争. 高质量单层二硫化钼薄膜的研究进展.
物理学报,2018,67:128103
|
CSCD被引
5
次
|
|
|
|
|
7.
吴木生. 应变对单层二硫化钼能带影响的第一性原理研究.
物理学报,2012,61:227102
|
CSCD被引
16
次
|
|
|
|
|
8.
Tao P.
J. Appl. Phys,2014,115:054305
|
CSCD被引
7
次
|
|
|
|
|
9.
Dang K Q.
J. Appl. Phys,2014,116:013508
|
CSCD被引
5
次
|
|
|
|
|
10.
Casillas G.
J. Phys. Chem. C,2015,119:710
|
CSCD被引
2
次
|
|
|
|
|
11.
李明林. 单层二硫化钼力学性能温度和手性效应的分子动力学模拟.
物理学报,2016,65:176201
|
CSCD被引
5
次
|
|
|
|
|
12.
Wang W D.
Nanotechnology,2017,28:164005
|
CSCD被引
3
次
|
|
|
|
|
13.
Wu J Y.
Nano Lett,2018,18:1543
|
CSCD被引
7
次
|
|
|
|
|
14.
Zhang R.
Appl. Phys. Lett,2016,108:042104
|
CSCD被引
9
次
|
|
|
|
|
15.
Hao S.
Appl. Phys. Lett,2017,110:153105
|
CSCD被引
2
次
|
|
|
|
|
16.
Yang Y.
Adv. Mater,2017,29:1604201
|
CSCD被引
4
次
|
|
|
|
|
17.
Yun W S.
Phys. Rev. B,2012,85:033305
|
CSCD被引
63
次
|
|
|
|
|
18.
Wang X.
Nanotechnology,2015,26:175703
|
CSCD被引
4
次
|
|
|
|
|
19.
Zhou W.
Nano Lett,2013,13:2615
|
CSCD被引
113
次
|
|
|
|
|
20.
Lin Z.
2D Mater,2016,3:022002
|
CSCD被引
24
次
|
|
|
|
|
了解气象卫星更多信息，请访问