Since the discovery of hexagonally self-ordered pore arrays in anodized of aluminum oxide (AAO)¹, great strides have been made not only in understanding the mechanistic underpinnings of pore formation^2-4 but also refinements to improve in the uniformity of arrays produced and enhance control over pore sizes^5-8. Much interest in these arrays stems from their potential applications in microfabrication processes. AAO membranes have been used as templates in the production of nanowires through electrodeposition of metals, alloys, and nanostructured alloys^9-13.

This paper presents a systematic study investigating the development of NiFe compositionally modulated nanowires for applications in biomedical devices. AAO membranes with different pore sizes were obtained with different electrolytes to fabricate nanowires with different diameters. Compositional modulation in NiFe alloy nanowires were created using double pulse scheme in electrodeposition. In addition, pulse schemes with different ramping schemes are used to create different compositional transitions between the modulations, which is characterized and verified using transition electron microscope with energy dispersive x-ray spectrometer. The anomalous interaction between Ni and Fe will be discussed in conjunction with the ramping pulse schemes and the ionic diffusion in the pores to explain the compositional profile along the wires.

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