Elastic Properties of GaN Nanowires: Revealing the Influence of Planar Defects on Young's Modulus at Nanoscale
Elastic Properties of GaN Nanowires: Revealing the Influence of Planar Defects on Young's Modulus at Nanoscale
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DOI：
10.1021/nl501986d
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发表时间：
2015-01-01
期刊：
影响因子：
10.8
通讯作者：
Zhu, Jing
中科院分区：
文献类型：
--
作者：
Dai, Sheng;Zhao, Jiong;Zhu, Jing
本工作通过原位电子显微镜研究了不同结构的氮化镓（GaN）纳米线的弹性性能。利用电场诱导共振方法表明，单晶GaN纳米线沿[120]方向，在直径92-110 nm范围内具有与体积值相似的杨氏模量。同时，首次通过原位SEM共振技术和原位透射电子显微镜拉伸测试揭示了钝角孪晶（OT）GaN纳米线的弹性行为。我们的结果表明，这些 OT 纳米线的平均杨氏模量大大降低至约 66 GPa，并且在直径范围 98-171 nm 处没有尺寸依赖性。基于经典力学中的混合规则，提出了对该现象的定量解释。研究表明，一维纳米材料的弹性模量取决于平面缺陷的相对取向和体积分数。
The elastic properties of gallium nitride (GaN) nanowires with different structures were investigated by in situ electron microscopy in this work. The electric-field-induced resonance method was utilized to reveal that the single crystalline GaN nanowires, along [120] direction, had the similar Youngs modulus as the bulk value at the diameter ranging 92-110 nm. Meanwhile, the elastic behavior of the obtuse-angle twin (OT) GaN nanowires was disclosed both by the in situ SEM resonance technique and in situ transmission electron microscopy tensile test for the first time. Our results showed that the average Youngs modulus of these OT nanowires was greatly decreased to about 66 GPa and indicated no size dependence at the diameter ranging 98-171 nm. A quantitative explanation for this phenomenon is proposed based on the rules of mixtures in classical mechanics. It is revealed that the elastic modulus of one-dimensional nanomaterials is dependent on the relative orientations and the volume fractions of the planar defects.