二维二硫化钨中的位错运动和晶界迁移。
Dislocation motion and grain boundary migration in two-dimensional tungsten disulphide.
机构信息
1] Department of Materials Science and Engineering, Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802, USA [2] Center for Two Dimensional and Layered Materials, Pennsylvania State University, University Park, Pennsylvania 16802, USA [3].
1] Department of Materials Science and Nano-Engineering, and the Richard Smalley Institute, Rice University, Houston, Texas 77005, USA [2].
出版信息
Nat Commun. 2014 Sep 9;5:4867. doi: 10.1038/ncomms5867.
Dislocations have a significant effect on mechanical, electronic, magnetic and optical properties of crystals. For a dislocation to migrate in bulk crystals, collective and simultaneous movement of several atoms is needed. In two-dimensional crystals, in contrast, dislocations occur on the surface and can exhibit unique migration dynamics. Dislocation migration has recently been studied in graphene, but no studies have been reported on dislocation dynamics for two-dimensional transition metal dichalcogenides with unique metal-ligand bonding and a three-atom thickness. This study presents dislocation motion, glide and climb, leading to grain boundary migration in a tungsten disulphide monolayer. Direct atomic-scale imaging coupled with atomistic simulations reveals a strikingly low-energy barrier for glide, leading to significant grain boundary reconstruction in tungsten disulphide. The observed dynamics are unique and different from those reported for graphene. Through strain field mapping, we also demonstrate how dislocations introduce considerable strain along the grain boundaries and at the dislocation cores.
位错对晶体的力学、电子、磁学和光学性能有重大影响。为了使位错在体晶体中迁移，需要几个原子的集体和同时运动。相比之下，在二维晶体中，位错出现在表面上，并且可以表现出独特的迁移动力学。最近在石墨烯中研究了位错迁移，但尚未有报道研究具有独特的金属-配体键合和三个原子厚度的二维过渡金属二卤代物的位错动力学。本研究提出了位错的运动，滑移动和攀移，导致二硫化钨单层的晶界迁移。直接原子尺度成像与原子模拟相结合揭示了滑移动能垒极低，导致二硫化钨中显著的晶界重构。观察到的动力学是独特的，与报道的石墨烯不同。通过应变场映射，我们还演示了位错如何在晶界和位错核处引入相当大的应变。
Zotero 插件