Department of Chemistry, University of Tennessee , Knoxville, Tennessee 37996, United States.
Faculty of Sciences, Holon Institute of Technology , Holon 58102, Israel.
Nano Lett. 2016 Feb 10;16(2):993-9. doi: 10.1021/acs.nanolett.5b03996. Epub 2016 Jan 12.
We bring together synchrotron-based infrared and Raman spectroscopies, diamond anvil cell techniques, and an analysis of frequency shifts and lattice dynamics to unveil the vibrational properties of multiwall WS2 nanotubes under compression. While most of the vibrational modes display similar hardening trends, the Raman-active A1g breathing mode is almost twice as responsive, suggesting that the nanotube breakdown pathway under strain proceeds through this displacement. At the same time, the previously unexplored high pressure infrared response provides unexpected insight into the electronic properties of the multiwall WS2 tubes. The development of the localized absorption is fit to a percolation model, indicating that the nanotubes display a modest macroscopic conductivity due to hopping from tube to tube.
我们结合同步辐射红外和拉曼光谱、金刚石压腔技术以及对频率位移和晶格动力学的分析，揭示了多壁 WS2 纳米管在压缩下的振动特性。虽然大多数振动模式显示出相似的硬化趋势，但 Raman 活性的 A1g 呼吸模式的响应几乎是其两倍，这表明应变下纳米管的破坏途径是通过这种位移进行的。同时，之前未被探索的高压红外响应为多壁 WS2 管的电子性质提供了意想不到的见解。局域吸收的发展适合于渗流模型，表明由于从一个管到另一个管的跳跃，纳米管表现出适度的宏观导电性。
