The role of the addition of Cu in alloyed and multilayered Fe-based nanowires

In this research, we focused on studies of the influence of Cu addition on the structure and magnetic properties of FeCu-alloyed and Fe/Cu-multilayered nanowires electrodeposited into polycarbonate membranes. It was observed that Cu addition prevents oxidation of overdeposited caps, compared to the surface of membranes filled with pure Fe, which immediately becomes covered with an oxide layer in the air. TEM studies revealed the polycrystalline structure of the multilayered NWs and confirmed that the wires were composed of alternating Fe and Cu layers. Magnetic studies performed using a SQUID magnetometer indicated a magnetic anisotropy with an easy axis along the nanowires. The increase in the Cu concentration in alloyed nanowires from 10% to 30%, resulted in an increase in both coercivity and squareness by about 30%. In the case of multilayered nanowires, significant reduction in squareness and non-monotonic changes in coercivity with the increase in Cu layer thickness were observed.