| Owing to its difficulty for accurately contact between the electrode and the objects to be measured, the traditional resistance testing method is not suitable for application in micro and/or nano structures. Developing new methods for resistance characterization of such kind of structures have been become the focus of nanotechnology. Scanning probe microscope (SPM) can observe the surface morphology of microcosmic material, and among which STM can test the nA current and has the advantage of micro or nano manipulations. This theses report a new method of resistance measurement of single T-ZnO, which provide a new thought of characterization of micro and/or nano structures and extending applications of SPM.T-ZnO was dispersed in water by magnetic stirring and ultrasonic dispersion. Then, test samples with good distributed T-ZnO on the conductive plate were prepared by making use of free settling of T-ZnO in water. The result showed that the T-ZnO distributed uniformly, and the roughness of the surface of the samples substantially reduced after being magnetically stirred and ultrasonically dispersed.In order to fix the T-ZnO on the conductive basal plate, we proposed a new method of nano-silver welding. We selected n-Ag/T-ZnO with different loadings of nano-silver. Thermal analysis (DSC/TG) indicated that the sample of0.5wt%n-Ag melted under thermal treatment in inert gas. Further investigation by SEM showed that the melted nano-silver flowed along the needles and mostly gathered at the needles’ tips of the carrier T-ZnO, providing a guarantee of connection between the whiskers and the basal plate.SPM morphology observation showed that both T-ZnO and n-Ag/T-ZnO without welding treatment got distortion images, which was ascribed to the moving of T-ZnO under actions of electric field and physical contact. After being treated by nano-silver welding, not only were good figures obtained, but also steadily measurement could be carried out. The resistance of a single T-ZnO is about2×105Ω. |
PDF Full Text Request