Wu Bin, Heidelberg Andreas, Boland John J
Centre for Research on Adaptive Nanostructures and Nanodevices and the Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
Nat Mater. 2005 Jul;4(7):525-9. doi: 10.1038/nmat1403. Epub 2005 Jun 5.
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.
纳米线作为纳米级互连以及电子和机电设备的有源部件已引起了广泛关注。纳米力学测量是一项挑战，但仍然是新型纳米线基器件开发和加工的关键。在此，我们报告了一种基于原子力显微镜针尖横向加载下纳米线弯曲来测量纳米线力学性能谱的通用方法。我们发现，对于金纳米线，杨氏模量基本上与直径无关，而屈服强度对于最小直径的线最大，强度高达块体材料的100倍，且远大于报道的块体纳米晶金属（BNM）的强度。与BNM不同，纳米线的塑性以应变硬化为特征，这表明位错运动和堆积在直径低至40nm时仍然起作用。文中讨论了纳米线和BNM不同力学性能的可能起源。
