Physical Properties Of TiO₂nanowire Assemblies: Measurement And Characterization

In recent years, the aggregation of "nano structure" has catched lots of attention from scholars. The study on the mechanical and electrical properties of the assembly is not only helpful to reveal the intrinsic correlation between the size and properties, but also useful for the development of micro nano sensors and electromechanical devices. So far, people have done a lot of research on the properties of nanomaterials, but few people have studied the properties of the assembly. In addition, Ti O2 as a semiconductor material, is widely used in making circuit components, sensors and so on. So it is important to study the mechanical and electrical properties of titanium dioxide assemblies.In this thesis, we firstly mentioned the combination of nano/micromanipulation instrument,microscope, Electrical measuring instrument, then use a variety of measurement model,finally we explore a method to measure the material mechanical and electrical properties of one-dimensional assembly. The main contents and test results are summarized as follows1. Using four probe model to measure the resistivity of titanium dioxide assembly. Then detailed describes the four probe method for measuring resistivity of Ti O2 assembly, and get the resistivity of 10 groups of Ti O2 assembly averaged in 1.16Ω?m, the standard deviation is about0.219Ω?m. The small standard deviation indicates that the measurement results are accurate.We studied the relationship between sample size and resistivity, and found that the resistivity of Ti O2 assembly whose diameter ranged in 166-458 μm, and the length ranged 166-458 um was independent of its size.2. Measured the Young’s modulus of Ti O2 assembly by bending method. This paper report using the method of cantilever beam bending to measure Young’s modulus of 10 groups of Ti O2 assembly ot, we get the values of Young’s modulus E=4.32 MPa, standard deviation sigma=0.248 MPa. In order to verify the cantilever beam bending method is reliable, we use three point bending method to measure the Young’s modulus of 10 groups of Ti O2 assembly, finally we get the values of Young’s modulus E=4.87 MPa, standard deviation sigma is 0.328 MPa. By comparison, we found that the young’s modulus of the two models were similar, which showed that the measurement results were accurate, the cantilever beam model and the three point bending model were suitable for Young’s modulus measurement of the Ti O2 assembly. At the same time, We also analyze the relationship between the young’s modulus and the sample size,and found that the young’s modulus is independent of the size of the sample, and the young’s modulus is the build-in properties of material.3. Measurement of the elastic coefficient of Ti O2 screw assemblies by tensile method. In this paper, we describe the process of measuring the elastic coefficient of Ti O2 screw assemblies by using the method of tensile test. In order to explore the relationship between the elastic coefficient and the sample size, we measured the elastic coefficient of the 10 groups of Ti O2 by using the MM3 A test system. By studying the relationship between the measured elastic coefficient and the sample size, we found that the elastic coefficient of the titanium dioxide screw assembly in the range of 10-60 was decreased with the increase of its length diameter ratio.To verify this rule, we use FT-RS1000 to measure the elastic coefficient of the 10 groups of Ti O2 screw assemblies, and analyze the relationship between the size and the elasticity coefficient.Finally, we found when the value of L/d between 15 an 50, the K is between 0.52 and 0.98N/m,what’s more,the elastic coefficient of the Ti O2 assembly was decreased with the increase of L/d.In this thesis, we measured the resistivity of TiO2 by four probe method, and analyzed the relationship between resistivity and sample size. It was found that the resistivity of the assembly was not dependent on the size of the material. In addition, the young’s modulus of the Ti O2 was measured by bending method. then the relationship between the young’s modulus and the sample size was analyzed, it was found that the young’s modulus of the assembly of Ti O2 was not size dependent. Finally, the elasticity coefficient of the 10 groups of Ti O2 was measured by tensile test. The relationship between the elasticity coefficient and the sample size was studied. The conclusion is that the ratio of the length to diameter ratio is in the range of 15-50, and the elastic coefficient of the Ti O2 assembly is reduced.