Temperature dependent magnetic properties of Co nanowires and nanotubes prepared by electrodeposition method

Abstract

Co nanowires (NWs) and nanotubes (NTs) with same length and different diameter have been deposited in anodized aluminum oxide templates by electrodeposition method at the room temperature. The Co NWs show hcp structure while Co NTs show poor crystalline with no strong texture. The spontaneous magnetization of the Co NWs was found to be parallel to the nanowires, while Co NTs have a transverse spontaneous magnetization. Magnetization reversal occurs by curling mode in Co nanotubes while nucleation mode in Co nanowires. Temperature dependent magnetic properties show that the thermal energy decreases at low temperature causing an increase in coercivity and saturation magnetization. The dominance of shape anisotropy in case of Co NWs is manifested by the weak temperature dependence of the enhanced coercive field. Magnetostatic interactions and magnetocrystalline anisotropy is found dominant in case of Co NTs due to their distinct geometry.