The size effects on magnetic properties of nanowires arrays were studied varying the nanowires diameter and maintaining the same periodicity among them, for two different nominal compositions of Co and Ni in the alloy form. The competition among magnetocrystalline and shape anisotropies changes drastically from smallest to biggest diameters altering the easy axis direction. In the case of 75% of Co in alloy, experimental values of the effective anisotropy constant (Keff) vary from positive to negative depending on the diameter, which means a reversal of the easy axis direction. For 50% of Co the shape anisotropy dominates over the magnetocrystalline for all studied diameters.
Highlights
► Highly ordered CoNi nanowire alloys have been produced by electrodeposition. ► Electrolyte temperature ensures the deposition of CoNi alloys instead of Co and Ni segregated. ► A competition between shape and magnetocrystalline anisotropies determines the direction of the easy magnetization axis. ► Analysis of the effective anisotropy gives us information respect to the easy axis modification.