Surface effect on resonant properties of nanowires predicted by an elastic theory for nanomaterials
Surface effect on resonant properties of nanowires predicted by an elastic theory for nanomaterials
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DOI：
10.1063/1.4927290
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发表时间：
2015-07
影响因子：
3.2
通讯作者：
Yin Yao;Shaohua Chen
中科院分区：
文献类型：
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作者：
Yin Yao;Shaohua Chen
采用最近发展起来的考虑表面效应的纳米材料连续介质理论，研究了不同边界条件下纳米线的共振特性。所采用的理论的主要特点是，在纳米材料的表面效应是由相应的块体材料的表面能密度和纳米尺度的表面弛豫参数。基于固定-固定梁模型和悬臂梁模型，得到了相应纳米线谐振频率的控制方程。对谐振频率进行了数值计算，计算结果与已有的数值计算结果吻合较好。与传统结构动力学预测的结果相比，固定-固定纳米线的谐振频率得到提高，而悬臂纳米线的谐振频率由于表面效应而减弱。减小特征尺寸（高度或直径）和增加纵横比都可以进一步增强两种纳米线的谐振特性的变化趋势。所得结果对纳米器件和纳米线相关纳米结构的设计具有一定的参考价值。
A recently developed continuum theory considering surface effect in nanomaterials is adopted to investigate the resonant properties of nanowires with different boundary conditions in the present paper. The main feature of the adopted theory is that the surface effect in nanomaterials is characterized by the surface energy density of the corresponding bulk materials and the surface relaxation parameter in nanoscale. Based on a fixed-fixed beam model and a cantilever one, the governing equation of resonant frequency for corresponding nanowires is obtained. Numerical calculation of the fundamental resonant frequency is carried out, the result of which is well consistent with the existing numerical ones. Comparing to the result predicted by the conventionally structural dynamics, the resonant frequency of a fixed-fixed nanowire is improved, while that of a cantilever nanowire is weakened due to the surface effect. Both a decreasing characteristic size (height or diameter) and an increasing aspect ratio could further enhance the varying trend of resonant properties for both kinds of nanowires. The present result should be helpful for the design of nano-devices and nanostructures related to nanowires.