Magnetically aligned single wall carbon nanotube films: Preferred orientation and anisotropic transport properties
Magnetically aligned single wall carbon nanotube films: Preferred orientation and anisotropic transport properties
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DOI：
10.1063/1.1536733
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发表时间：
2003-02-15
影响因子：
3.2
通讯作者：
Smalley, RE
中科院分区：
文献类型：
--
作者：
Fischer, JE;Zhou, W;Smalley, RE
在强磁场作用下，利用悬浮液过滤沉积制备了具有平面内择优取向的单壁碳纳米管厚膜。我们用x射线光纤图和偏振拉曼散射来表征场致对准，使用一个包含完全未对准部分的模型。我们将纹理参数与平行和垂直于取向方向的电阻率和导热系数相关联。比较了7 T场和26 T场的结果。我们发现分布宽度与场无关，而排列分数在高场处略大。两种输运性质的各向异性都不大，比率在5-9之间，与假设刚性棒导体的简单模型所测得的织构参数一致。我们认为，进一步增强各向异性性能需要优化滤波器沉积工艺，而不是更大的磁场。我们表明，x射线和拉曼数据都需要用于取向SWNT材料的完整纹理分析。(C) 2003年美国物理研究所。
Thick films of single wall carbon nanotubes (SWNT) exhibiting in-plane preferred orientation have been produced by filter deposition from suspension in strong magnetic fields. We characterize the field-induced alignment with x-ray fiber diagrams and polarized Raman scattering, using a model which includes a completely unaligned fraction. We correlate the texture parameters with resistivity and thermal conductivity measured parallel and perpendicular to the alignment direction. Results obtained with 7 and 26 T fields are compared. We find no significant field dependence of the distribution width, while the aligned fraction is slightly greater at the higher field. Anisotropy in both transport properties is modest, with ratios in the range 5-9, consistent with the measured texture parameters assuming a simple model of rigid rod conductors. We suggest that further enhancements in anisotropic properties will require optimizing the filter deposition process rather than larger magnetic fields. We show that both x-ray and Raman data are required for a complete texture analysis of oriented SWNT materials. (C) 2003 American Institute of Physics.