Effect of Mn (12 at%) Substitution on Magnetic Anisotropy and Magnetization Reversal of Equiatomic FeCo Alloy Nanorod Arrays

Abstract The effect of manganese (Mn) substitution on magnetic properties of equiatomic FeCo (1:1) alloy nanorod arrays was investigated by comparatively analyzing Fe50Co50 and Fe45Co43Mn12 nanorod arrays having diameter and length about 50 nm and 250 nm respectively. The Fe45Co43Mn12 nanorod arrays were also annealed under vacuum at 400 °C , 500 °C , and 600 °C in order to further improve their properties. The Fe50Co50 and Fe45Co43Mn12 nanorod arrays showed body-centered cubic (bcc) structure while after annealing at 600 °C a hexagonal close pack (hcp) Co phase was also induced in Fe45Co43Mn12 nanorod arrays. The effective anisotropy field ( H k ) was determined through anisotropy field distribution method and magnetization reversal was examined by angular dependence of coercivity ( H c ). The angular dependence of H c demonstrated that the magnetization reversal in Fe50Co50 nanorods occurred via coherent rotational mode while magnetization reversal in Fe45Co43Mn12 nanorods occurred by the combination of both coherent rotational and curling mode.