A Study of Ta 2 O 5 Nanopillars with Ni Tips Prepared by Porous Anodic Alumina Through-Mask Anodization.

The paper discusses the formation of Ta 2 O 5 pillars with Ni tips during thin porous anodic alumina through-mask anodization on Si/SiO 2 substrates. The tantalum nanopillars were formed through porous masks in electrolytes of phosphoric and oxalic acid. The Ni tips on the Ta 2 O 5 pillars were formed via vacuum evaporation through the porous mask. The morphology, structure, and magnetic properties at 4.2 and 300 K of the Ta 2 O 5 nanopillars with Ni tips have been studied using scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry. The main mechanism of the formation of the Ta 2 O 5 pillars during through-mask anodization was revealed. The superparamagnetic behavior of the magnetic hysteresis loop of the Ta 2 O 5 nanopillars with Ni tips was observed. Such nanostructures can be used to develop novel functional nanomaterials for magnetic, electronic, biomedical, and optical nano-scale devices.