Magnetization Reversal and Surface Spins in Electrodeposited Co₉₀Mn₁₀ Alloy Nanowires

In this work, Co_1−XMn_X(X= 10) nanowires have been prepared by DC electrodeposition into anodized aluminum oxide (AAO) templates. A systematic study has been done about the effects of nanowires composition on the shapes of MH curves and magnetic properties. It is observed from XRD pattern that Co₉₀Mn₁₀ nanowires have polycrystalline structure with dominant FCC Cobalt phase. The M-H curves at two angles between magnetic field and nanowires axis define a clear and sharp anisotropic behavior. The magnetization reversal mechanism is found to be curling mode for certain angle between applied magnetic field and nanowires axis and then by nucleation mode. In order to elucidate the transition temperature, temperature dependent magnetization properties for Co₉₀Mn₁₀ nanowires at different applied fields have also been measured. The transition temperature or freezing temperature is found to be 350 K. The bifurcation of FC and ZFC curves is explained by the freezing of the surface spins, depinning of the domain walls and superparamagnetic nanoparticles on the surface of the nanowires.