| It is well known that the macroscopic materials have large size, which can be seen as an infinite crystal, thus the model of the materials could be simplified as much as possible. However, when the size of the materials becomes smaller and smaller to micrometer and nanometer, it cannot be seen as an infinite crystal any more due to the internal atom, so the model before should be modified. Meanwhile, nanoscale materials have huge specific area so the ratio of atoms which in the surface is increasing and the physical and chemical properties of the nanoscale materials are changed. It is important that the properties are tested by micro- or nano- measurement.One-dimensional ZnO nanostructure has fantastic properties in mechanics and electricity, which make it has a promising application in MEMS, sensor and resource. At present, the attention is concentrated on high productivity of the one-dimensional ZnO nanostructure, the control of structures and properties and the methods of testing the properties and so on.In this paper, we discuss the preparation of the one-dimensional ZnO nanostructure and themicroscale properties. The main point and result are as follows:1.ZnO nanowires are synthesized by thermal evaporation. The length is tens micrometer and the diameter is 200~300 nanometer; ZnO nanohelices are synthesized in the higher temperature zone by mixing the ZnO, Sb, and Li2CO3 in ratio of weight 5:1:2.5. Also, in the lower temperature zone ZnO nanocoils are prepared and the growth mechanism is analyzed. By mixing ZnO, In and Ga2O3 in 5:1:1, zigzag ZnO nanowires are compounded.2.The mechanical properties of individual ZnO nanowire are tested by nanoprobe with crosswise force. A nanowire which length is 22.6μm and diameter is 220 nm is selected to measure the relationship between Force and Displacement. According to the F-d curve, we can get the K=8.62N/m. And the Young’s modulus is 288.6GPa which is calculated by formula based on cantilever. Another five nanowires are tested with the same method, and the average value of Young’s modulus is 289.52 GPa. We also select a nanowire which length is 12.3μm and diameter is 260 nm and apply a lengthwise force. We measure K=13.28N/m and the Young’s modulus is 337 GPa based on formula of two-end fixed beam. Another five nanowires are measured and the average Young’s modulus is 324 GPa.Young’s modulus of ZnO nanowires is almost same on the two direction of force. Due to the scale effect of nanomaterials, the Young’s modulus of nanowires is greater than block.3.the resistivity of the ZnO film is measured by nanoprobe and semiconductor measuring system and the value is 10-4Ω·cm. We also test the change of the conductivity by using green light and purple light and the purple light could enhance the conductivity most. Then, the individual ZnO nanowire is dispersed by alcohol and separated by manipulator. The conductivity of individual ZnO nanowire is 15.2 S·cm-1 which is lower than the block because of boundary scattering effect. The resistance of zigzag ZnO nanowire is 1.54×106Ω measured by the same medthod and the value of ZnO nanowire of the same length is 3.89×105Ω. The zigzag ZnO nanowire always changes the direction of growth and the boundary of crystal may hinder the transmission of electron so the electrical conductivity of zigzag nanowire is lower than nanowire.The method which we put forward for the experiment has greatly reduced the requirement for the sample and simplifies the tedious process of sample preparation, and through the analysis of proprietary software to analyze data and concluded that enhanced the accuracy of experimental results. |
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