以Y/Ni为催化剂制备的单壁碳纳米管的拉曼光谱研究

采用电弧放电法以Y/Ni为催化制备了单壁碳纳米管（SWNTs），对样品进行了扫描电镜、透射电镜和拉曼光谱的研究。所制备的样品中单壁碳纳米管的含量较高。对单壁碳纳米管的共振拉曼散射增强效应进行了观察，随激光波长的不同，单壁碳纳米管的拉曼光谱也随之变化，尤其是低频区径向呼吸模的变化比较明显。利用布里渊区折叠法计算了单壁碳纳米管的电子态密度曲线，根据SWNTs电子态密度尖峰之间的能量差、管子的直径和呼吸模频率建立了一个图表，并对SWNTs的呼吸模进行了归属。分析结果表明：样品中单壁碳纳米管的直径分布在0.79-1.76nm范围，金属管和半导体管均存在，并且直径在1.45nm附近的碳管居多。

Raman Scattering of Single-wall Carbon Nanotubes Produced Using Y/Ni Catalyst

Single wall carbon nanotubes (SWNTs) were synthesized by electric arc discharge method with a mixture of nickel and yttrium as catalysts.The examination results of scanning electronic microscope and transmission electronic microscope indicate that the yield of SWNTs in the sample were high.SWNTs have been investigated by Raman scattering techniques with excitation wavelengths in the range of 514 5 to 782 0 nm.We have observed some differences in the frequencies and intensities of the radial breathing modes.The electronic density of states of SWNTs was calculated using the Brillouin zone folding.A graphical method was proposed for assigning Raman peaks of the radial breathing modes (RMB) based on the data of diameters,RBM frequencies and electronic density of states of SWNTs.The radial breathing modes on SWNTs are assigned.The results indicate that the diameter distribution of SWNTs is in the range of 0 79-1 76 nm,and the SWNTs with diameter 1 45 nm are in the majority.The metallic and semiconductor tubes are all present in the sample.