Tailoring magnetic properties in arrays of pulse-electrodeposited Co nanowires: The role of Cu additive

In this study, we aim to report the role of Cu additive in arrays of pulse-electrodeposited Co nanowires (NWs) with diameters from 30 to 75nm, embedded in porous aluminum oxide templates. This features the role of Cu additive in composition and crystalline characteristics as well as in the magnetic properties of Co NWs. Increasing the duration of off-time between pulses during the electrodeposition of Co NWs made it possible to increase the amount of Cu content, so that Co-rich CoCu NWs were obtained. The parallel coercivity and squareness values increased up to 1500Oe and 0.8 for 30nm diameter Co94Cu6 NWs, starting from 500Oe and 0.3 for pure Co NWs. On the other hand, although there was a substantial difference between the crystalline characteristics of 75nm diameter pure Co and CoCu NWs, no considerable change in their magnetic properties was observed using hysteresis loop measurements. In this respect, the first-order reversal curve (FORC) analysis revealed strong inter-wire magnetostatic interactions for the CoCu NWs. Moreover, we studied the effect of thermal annealing, which resulted in an increase in the coercivity of CoCu NWs with different diameters up to 15%. As a result, the addition of small amount of Cu provides an alternative approach to tailoring the magnetic properties of Co NWs. [Display omitted] •Fabrication of pure Co and CoCu NWs with different diameters using a pulsed method.•Role of Cu additive in composition, crystalline structure and magnetic properties.•Improvement in coercivity and squareness up to 1500 Oe and 0.8 using Cu additive.•Using FORC diagrams for the magnetic characterization of CoCu NWs.•Investigating the effect of thermal annealing on magnetic properties of CoCu NWs.