Direct force measurements and kinking under elastic deformation of individual multiwalled boron nitride nanotubes
Direct force measurements and kinking under elastic deformation of individual multiwalled boron nitride nanotubes
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DOI：
10.1021/nl070863r
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发表时间：
2007-07-01
期刊：
影响因子：
10.8
通讯作者：
Bando, Yoshio
中科院分区：
文献类型：
--
作者：
Golberg, Dmitri;Costa, Pedro M. F. J.;Bando, Yoshio
不同直径(40~100 nm)的多壁氮化硼纳米管在300KV高分辨率电子显微镜(TEM)中被弯曲，采用新型全集成的TEM-原子力显微镜(AFM)压电驱动夹持器，连续记录力-压电位移曲线。这些管子在可压电铝丝和硅悬臂之间被原位(即在电子显微镜内)轻轻压缩。通常，弯曲应力值从类似于100到类似于260兆帕，对应于0.5-0.6 TPA的弹性模数。直到非常大的弯曲角(超过115度)时，都不会出现管子的严重故障。弯曲角度超过30-40度会导致BN纳米管的弹性变形，并通过连续的瞬间扭结传播进行。它们的作用是累积弯曲曲率，而不是在压缩载荷下均匀卷曲管子。这些扭结在重新加载时是完全可逆的，没有(或边缘)残余塑性变形的痕迹。
Individual multiwalled boron nitride nanotubes of different diameters (40-100 nm) were bent inside a 300 kV high-resolution transmission electron microscope (TEM) using a new fully integrated TEM-atomic force microscope (AFM) piezodriven holder under continuous recording of force-piezodisplacement curves. The tubes were gently compressed in situ (i.e., inside the electron microscope) between a piezomovable aluminum wire and a silicon cantilever. Typically, bending stress values ranging from similar to 100 to similar to 260 MPa, and corresponding to elastic moduli of 0.5-0.6 TPa, were estimated. Tube gross failures were absent up to very large bending angles (in excess of 115 degrees). Extending the bending angles beyond 30-40 degrees resulted in the elastic deformation of BN nanotubes, which proceeded through the propagation of consecutive momentary kinks. These had the effect of accumulating a bending curvature rather then uniformly curl the tube under the compression load. These kinks were found to be entirely reversible on reloading with no (or marginal) traces of residual plastic deformation.