Abstract
Single-crystalline RuO2 nanowires were grown by using a thermal evaporation method. A control of the sizes _width and length_ and the length-to-width ratio of the nanowires were achieved by tuning the growth time. A transmission electron microscope–scanning tunneling microscope technique invoking one-nanocontact electrical characterization was adopted to determine the room-temperature resistivity ~100 μΩ-cm of the nanowires. An e-beam lithography technique facilitating two-nanocontact measurements was performed to establish the metallic characteristic of individual nanowires. The authors found that a nanocontact may introduce high contact resistance, nonlinear current-voltage characteristics, and even semiconducting behavior in the temperature dependent resistance. And a nanocrystalline ZrNxOy thin film was deposited using hollow cathode discharge ion-plating (HCDIP). ZrO2 and ZrN phases were detected by X-ray diffraction in the as-deposited film, suggesting phase separation during the growth process. This research performed a transmission electron microscopy (TEM) study on the mechanism of phase-separation and distribution in ZrNxOy thin films and related the phase fraction with the film properties. Since the crystallographic orientations of the ZrO2 and ZrN phases are random, the microstructure of the separated phases is studied with multiple central dark-field (MCDF) technique. The compositional distribution between the separated phases is analyzed with nano-beam energy dispersive X-ray spectroscopy (EDX). The results showed that zirconium oxynitride (ZrNxOy) thin film has a columnar structure with an alternate arrangement of columns of ZrN and ZrO2, indicating that oxygen atoms are inter-columnarly segregated with a lateral diffusion distance lower than 20 nm.