An Array of Concentric Composite Nanostructures of Zirconia Nanotubules/Cobalt Nanowires: Preparation and Magnetic Properties

Abstract

Zirconia nanotubules, filled with crystalline cobalt rods (see Figure), were prepared in a reaction sequence of sol–gel crystallization of ZrO2 from zirconyl chloride octahydrate around a template of commercial porous anodic alumina, followed by electrodeposition of cobalt from CoSO4 solution and template removal with 6 N NaOH. The composite shows uniaxial magnetic anisotropy and a coercivity exceeding that of bulk cobalt.