Electrical and structural characterization of electrodeposited Ni nanowires

Abstract

Nanowires (NW) have received much attention due to their shape anisotropy, high aspect ratio, relatively large surface area and particular electron transport properties. In addition, NW can be used as sensor devices for several applications, since they present high sensitivity to the environment. One of the major challenges when dealing with transport measurements in NW is to trap them between electrodes, which allows electrical characterization and therefore fabrication of nanowire-based devices. Electrically neutral NW can be deposited by dielectrophoresis (DEP) method, which requires the application of an alternating electric field between electrodes. In this work, Ni nanowires (NiNW) fabricated by electrodeposition technique and properly dispersed in a DMF solution were deposited on top of Pt electrodes using the DEP method. The deposited NiNW exhibit initially a Schottky-like current versus voltage behavior due to the high contact resistance between NiNW and electrode. Its reduction down to two orders of magnitude, reaching value less than the NiNW resistance, was achieved by depositing an ion beam-assisted 10 nm-thick Pt layer over the NW extremities. Therefore, this method presents a suitable process of NW deposition and electrical characterization. This can be used for investigation of electrical transport properties of individual NW and fabrication of NW-based devices, such as sensors and field effect transistors. Especially for ferromagnetic NW, one can use the present method for fabrication of magnetic field-effect transistors (MagFET).