Effect of stacking faults on magnetic properties and magnetization reversal in Co nanowires

Ferromagnetic 3d transition metal nanowires based on the assembly of shape anisotropy seem apt candidates to replace materials based on rare-earth elements in current permanent magnets. Recently, great efforts have been devoted into enhancing the coercivity of Co nanowires, through accurate control of shape and morphology. Nevertheless, stacking faults can be formed relatively easily in close-packed metals like Co, and its effect on the magnetic properties was usually obscured by the geometrical effect and being ignored. In this work, the Co nanowires with different aspect ratios were synthesized by solvothermal chemistry processes. The effect of aspect ratio on the magnetic properties of Co nanowires was investigated, and a high magnetic property with a coercivity of 9 kOe was obtained in the Co nanowires with an aspect ratio of 10. The stacking faults were observed in the Co nanowires with an aspect ratio beyond 10, which may be a contributing factor to the lower coercivity than expected. The micromagnetic simulation was employed to reveal the effect of stacking faults on the magnetization reversal mechanism, based on which the coercivity degradation mechanism was discussed. This work is instructive for developing high-performance magnetic nanowires.