Magnetic Field Annealing Effects on Magnetic Properties of Electrodeposited Co/Cu Multilayered Nanowires

Co/Cu nanowires were fabricated by electrodeposition using anodic alumina templates, with 100 nm diameter nanopores. The thickness of Co and Cu layer was about 45 and 5 nm, respectively. The magnetic properties of multilayered nanowires have been studied before and after simple and magnetic field (MF) annealing. For simple annealing, an increase in coercivity and squareness (SQ) along easy axis of magnetization has been observed. Magnetic field annealing has been done under MF of 1 T. For comparison, the MF annealing effect on magnetic properties has been studied using fast and slow temperature variations. The corresponding change in saturation magnetization, coercivity, remanent SQ, and the shape of hysteresis loops has been investigated. The coercivity Hc decreases in case of MF annealing with fast temperature variation, whereas it increases in case of MF annealing with slow temperature variation, as compared with as deposited. The enhanced magnetic anisotropy has been observed by slow MF annealing (SMFA), whereas magnetic anisotropy attenuated a little by fast MF annealing. Annealing without MF has also shown the enhanced magnetic anisotropy. SMFA and annealing without MF is likely to improve the interface of Co/Cu.