Magnetic nanowires via template electrodeposition

The magnetic NiFe_x nanowires were prepared via template-guided electrodeposition. Anodized nanoporous aluminum was used as a template. The pore density and dimensions of alumina templates can be controlled by anodization conditions. Magnetic nanorods (or nanowires) with various aspect ratios were prepared by controlling the electrodeposition time. SEM and TEM micrographs revealed the wire and rod shape morphologies with 50 nm in diameter and 1.5 ~ 10 μm in length. Elemental analysis and ESCA studies suggested that NiFe ₃ magnetic alloy was formed. The X-ray diffraction pattern indicates that all the nanowires are stabilized in a BCC structure with a [1 1 0] texture oriented along the long axis of the nanowires. The magnetic measurement showed no hysteresis loops for the whole aspect ratios of the nanowires. Nevertheless, the magnetization is more temperature sensitive for nanowires with lower aspect ratio. This is caused by the fact that the easy magnetization axis is always parallel to the long axis of the nanowires.