Mechanical properties of ultrahigh-strength gold nanowires
Mechanical properties of ultrahigh-strength gold nanowires
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DOI：
10.1038/nmat1403
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发表时间：
2005-07-01
期刊：
影响因子：
41.2
通讯作者：
Boland, JJ
中科院分区：
文献类型：
--
作者：
Wu, B;Heidelberg, A;Boland, JJ
纳米线作为纳米尺度的互连以及作为电子和机电设备的有源部件已经吸引了相当大的兴趣。纳米力学测量是一个挑战，但仍然是开发和处理新型基于纳米晶的设备的关键。在这里，我们报告了一种通用的方法来测量纳米线的机械性能的光谱的基础上弯曲的纳米线下的横向负载从原子力显微镜针尖。我们发现，对于Au纳米线，杨氏模量基本上是独立的直径，而屈服强度是最大的最小直径的线，强度高达100倍的散装材料，并大大大于散装纳米晶金属（BNM），。与BNM相反，纳米线塑性的特征在于应变硬化，这表明位错运动和堆积在直径为40 nm时仍然有效。纳米线和BNM的不同的机械性能的可能起源进行了讨论。
Nanowires have attracted considerable interest as nanoscale interconnects and as the active components of both electronic and electromechanical devices. Nanomechanical measurements are a challenge, but remain key to the development and processing of novel nanowire-based devices. Here, we report a general method to measure the spectrum of nanowire mechanical properties based on nanowire bending under the lateral load from an atomic force microscope tip. We find that for Au nanowires, Young's modulus is essentially independent of diameter, whereas the yield strength is largest for the smallest diameter wires, with strengths up to 100 times that of bulk materials, and substantially larger than that reported for bulk nanocrystalline metals (BNMs),,,,. In contrast to BNMs, nanowire plasticity is characterized by strain-hardening, demonstrating that dislocation motion and pile-up is still operative down to diameters of 40 nm. Possible origins for the different mechanical properties of nanowires and BNMs are discussed.