Towards smooth and pure iron nanowires grown by electrodeposition in self-organized alumina membranes

Abstract Due to their high aspect ratio, magnetic nanowires are interesting for various applications. Fe nanowires are of particular interest due to their high magnetization, which suggests high shape anisotropy is possible. Here, we show how the electrodeposition process can be adapted to the constraints of a high aspect ratio template in order to approach an ideal behaviour of smooth and pure Fe nanowires. An adjustment of the Fe2+ concentration and the addition of H3BO3 result in smooth and continuous nanowires; saturation polarization is achieved, together with an anisotropy field of up to 70% compared to pure Fe. Mossbauer spectroscopy reveals a negligible amount of impurities. Together with magnetic measurements we show that shape anisotropy aligns the preferential magnetization axis along the wire axis.