Nanoscale characterisation and magnetic properties of Co81Cu19/Cu multilayer nanowires

Abstract

Bamboo-like CoCu/Cu multilayer nanowires have been successfully fabricated into anodic aluminium oxide templates using an electrodeposition method, and their chemistry and crystal structure have been characterised at the nanoscale. Energy-dispersive X-ray analysis indicated that the chemical composition of the regular periodic CoCu/Cu nanowires was Co₈₁Cu₁₉/Cu. Diffraction analysis revealed that Cu layers and Co-rich layers exhibited polycrystalline fcc structures. A twin relationship of Cu layer {111} planes stacking on Co₈₁Cu₁₉ layer {111} planes was observed at the lattice-resolution level. The magnetic properties analysed by experimental and theoretical simulations showed that there was a transition from a curling rotation mode to coherent rotation mode in our Co₈₁Cu₁₉/Cu multilayer nanowires when the angle between external field and nanowire length axis increased from 0° to 90°. This study highlights the basic morphological, chemical, structural information and magnetic reversal mechanism of CoCu/Cu nanowires, which are critical for the applications of multilayer nanowires in nanoscale sensors and electronics.