Reactive bimetallic Al/Ni nanostructures for nanoscale heating applications fabricated using a porous alumina template

Abstract

Porous alumina templates are attracting increasing attention for the growth of nanowires and nanodots. We demonstrate here the fabrication of reactive bimetallic nanoporous Al/Ni films and Al/Ni nanorods by electron gun evaporation on a very thin porous alumina template, with vertical cylindrical pores 160 nm in height and 60 nm in diameter. Al and Ni were deposited consecutively on the template and a bimetallic Al/Ni nanorod 60 nm in height and in diameter was formed in each pore, while a porous bimetallic Al/Ni capping layer was produced on top of the porous alumina template. The porous reactive bimetallic capping layer was ignited using a spark and a crater was formed around each ignition point with microspheres of the nickel aluminides products. The obtained results offer a first insight into the development of reactive nanorods and porous thin films capable of providing a thermally actuated valving mechanism for flows into and/or out of anodized aluminium oxide membranes and nanotubes, e.g. for targeted drug delivery.