Electrical/dielectric properties of tantalum nanotube arrays via porous-alumina-assisted electrodeposition from ionic liquid

abstract

English

The success of first work on ED of Ta over a planar substrate inspired us to advance the technique striving to create an array of spatially ordered Ta and Ta2O5 nanostructures via electrodeposition from IL through nanopores in a thin-film alumina template anodically formed. The porous anodic alumina template, having ~100-nm wide and 1-m long pores, was prepared by anodization of an Al/W/Ti trilayer sputtered onto a Si wafer. ED of Ta was carried out using IL ([BMP]Tf2N), containing 0.25M TaF5 and 0.25M LiF. Continuous Ta and the free-standing arrays of Ta nanotubes filling the alumina pores were achieved via potentiostatic ED through the reduction of tantalum in the IL in a series of steps from Ta(V) to a final insoluble Ta-containing product. A prolonged deposition time caused the deposit to come out from the pores and make either a dot-like, netlike or continuous coverage on the template surface. The recorded current-voltage curves revealed a bipolar resistive switching event in the films, when the behavior changes abruptly and reversely from a high resistance state to a low resistance state in a smaller voltage range. Electrochemical impedance spectroscopy measurements of the as deposited and partly anodized nanocoatings revealed the development of various semiconductor/metal interfaces, the results to be discussed in due course. This work was supported in part by project CZ.1.07/2.3.00/30.0039 of BUT, GAČR grant no.14-29531S and project CZ.1.05/2.1.00/01.0012.

tantalum, electrodepositon, porous anodic alumina, I/V curves

ŠIMŮNKOVÁ, H.; KALINA, L.; BOUŠEK, J.; MOZALEV, A.

11. 5. 2015

E-MRS Spring Meeting, Lille, France

http://www.european-mrs.com/2015-spring-symposium-ff-european-materials-research-society