Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Radial breathing mode of carbon nanotubes subjected to axial pressure | Lei et al. Nanoscale Research Letters 2011 6 492 http content 6 1 492 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Radial breathing mode of carbon nanotubes subjected to axial pressure 1 -S HI 1 3 Xiao-Wen Lei Qing-Qing Ni Jin-Xing Shi and Toshiaki Natsuki Abstract In this paper a theoretical analysis of the radial breathing mode RBM of carbon nanotubes CNTs subjected to axial pressure is presented based on an elastic continuum model. Single-walled carbon nanotubes SWCNTs are described as an individual elastic shell and double-walled carbon nanotubes DWCNTs are considered to be two shells coupled through the van der Waals force. The effects of axial pressure wave numbers and nanotube diameter on the RBM frequency are investigated in detail. The validity of these theoretical results is confirmed through the comparison of the experiment calculation and simulation. Our results show that the RBM frequency is linearly dependent on the axial pressure and is affected by the wave numbers. We concluded that RBM frequency can be used to characterize the axial pressure acting on both ends of a CNT. 1. Introduction Radial breathing mode RBM of carbon nanotubes CNTs is a low frequency mode but accounts for the strongest feature observed in the CNT Raman spectrum. For the RBM all of the carbon atoms in a CNT move in the radial direction synchronously which generates an effect similar to breathing 1 2 . This mode is unique to CNTs and is not observed in other carbon systems 3 . Resonant Raman measurement of the RBM in CNTs is a standard straightforward method for precisely determining the diameter of a CNT distinguishing the CNT chiral-index assignments or characterizing CNT conglomerates 4-7 . For CNTs pressure studies are motivated by the need to investigate mechanical stability pressure-induced phase transitions such as vibrational characteristics and the effects of intertube interactions. In this letter the RBM .
