Fabrication of magnetic core–shell Fe nanowires by electrochemical deposition

Abstract

Abstract Highly-ordered Fe nanowires (NWs) were successfully electrodeposited in a laboratory made anodic aluminum oxide template with a diameter of 30 nm. The as prepared Fe NWs were used as a substrate to prepare core–shell Fe@Fe 3 O 4 NWs after annealing and hydrogen reduction at high temperature. The phase transformation of the oxide shell of electrodeposited Fe NWs took the form Fe 2 O 3 → α-Fe 2 O 3 → Fe 3 O 4 . Transmission electron microscopy images revealed that the surface of Fe@Fe x −1 O x NWs was smooth and orderly, and the oxide layer was dense and uniform. The magnetic analysis of Fe@Fe x −1 O x nanowires was carried out using a vibrating sample magnetometer. It was found that Fe@Fe 3 O 4 nanowires manifested the characteristics of super-paramagnetism in the direction perpendicular to the nanowires due to smaller coercive force, and they can be suitable material for future biomedical applications.