Synthesis and magnetic behavior of an array of nickel-filled carbon nanotubes.

Highly-ordered arrays of Ni-filled carbon nanotubes have been fabricated by a second-order template method. First, an array of aligned carbon nanotubes was generated in a porous alumina membrane by catalytic pyrolysis of acetylene. The desired material, such as nickel, was then filled into the aligned carbon nanotubes by electrodeposition. The remarkable features of this method are: (i) high yield of metal-filled carbon nanotubes, and (ii) the wall thickness of the carbon nanotubes, and the length, diameter, and structure of the metal nanowires in the carbon nanotubes are controllable via changing experimental conditions. This method should be applicable for preparation of other metal- and alloy-filled carbon nanotubes, and allow the reliable technological application in nanoelectronic devices, high-density magnetic memories, electrochemical energy storages and sensors, etc. [ABSTRACT FROM AUTHOR]