Department of Physics, HKU-Shenzhen Institute of Research and Innovation (HKU-SIRI), HKU-CAS Joint Laboratory on New Materials, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
Mathematics and Physics Centre, Department of Mathematical Sciences, Xi'an Jiaotong-Liverpool University, Suzhou 215123, China.
Sci Rep. 2016 Sep 13;6:33091. doi: 10.1038/srep33091.
Transition-metal dichalcogenides (TMDs) nanostructures including nanotubes and monolayers have attracted great interests in materials science, chemistry to condensed matter physics. We present an interesting study of the vibration modes in multi-walled tungsten sulfide (WS2) nanotubes prepared via sulfurizing tungsten oxide (WO3) nanowires which are investigated by confocal micro-Raman spectroscopy. The inter-layer vibration mode of WS2 nanotubes, A1g, is found to be sensitive to the diameter and curvature strain, while the in-plane vibration mode, E(1)2g, is not. A1g mode frequency shows a redshift by 2.5 cm(-1) for the multi-layered nanotubes with small outer-diameters, which is an outcome of the competition between the Van der Waals force stiffening and the curvature strain softening. We also show that the Raman peak intensity ratio is significantly different between the 1-2 wall layered nanotubes and monolayer flat sheets.
过渡金属二硫属化物（TMDs）纳米结构包括纳米管和单层，在材料科学、化学和凝聚态物理领域引起了极大的兴趣。我们展示了一项有趣的研究，即通过硫化氧化钨（WO3）纳米线制备的多壁二硫化钨（WS2）纳米管的振动模式，该研究通过共焦微拉曼光谱进行了研究。WS2 纳米管的层间振动模式 A1g 被发现对直径和曲率应变敏感，而面内振动模式 E(1)2g 则不敏感。对于具有较小外径的多层纳米管，A1g 模式的频率显示出 2.5 cm-1 的红移，这是范德华力增强和曲率应变软化之间竞争的结果。我们还表明，1-2 壁层状纳米管和单层扁平片之间的拉曼峰强度比有显著差异。
