Abstract
In first part of the experiments, we carry out a series of electrical measurements and discussions on the TaSi2 nanowires. In this research, we get a large discrepancy in the two-probe measured resistance from various two-probe devices. In general, a total resistance containing both of the contact resistance and the wire resistance is measured by the two-probe technique. In order to avoid the influence by contact resistance, we solve the problem in two directions. First, the four-probe measurement technique is utilized to get real resistance of the TaSi2 nanowires itself. Second, we want to reduce the effects of contact resistance by increasing the width of contact electrode. But in this part, the measured two-probe resistance doesn’t show much dependence on different contact electrode width. Hence, we suspect that this may be caused by the residual solvent contaminants on the nanowires before metal deposition. On the other hand, I-V measurement at different temperatures (T＜300K) reveals the TaSi2 nanowire with a residual resistance at very low temperature exhibits a classical metallic behavior. Finally, we find the TaSi2 nanowire can bear a high current density of 3×108 A/cm2 before failure through the melting test. The result indicates that TaSi2 nanowire may be a promising candidate for the next generation nano-device interconnecting application.In the second part, tungsten oxide and iron oxide nanowires are studied. Due to their semiconducting nature, we are interested in the exploration of their field effect characteristics. In the measurement of tungsten oxide nanowires, we don’t find a proper ohmic contact metal in the available materials. In addition, no field effect appears when applying high gate voltage from +20 volt to -20 volt. By exploring its surface chemistry behavior, the resistance of WO3 nanowire is not changed when measuring in the air and in the high vacuum environment. This is different from the behavior exhibits in the Fe2O3 nanowires. On the other hand, due to the semiconducting property of the Fe2O3 nanowire, it has the potential application in the nano-scale field effect transistor. But due to the difficulty in sample preparation, there are not much data to express in this study.