Saeki Ryusei, Ohgai Takeshi
Graduate School of Engineering, Nagasaki University, Bunkyo-machi 1-14, Nagasaki 852-8521, Japan.
Faculty of Engineering, Nagasaki University, Bunkyo-machi 1-14, Nagasaki 852-8521, Japan.
Materials (Basel). 2018 Nov 22;11(12):2355. doi: 10.3390/ma11122355.
The crystal growth process and ferromagnetic properties of electrodeposited cobalt nanowires were investigated by controlling the bath temperature and cathodic overpotential. The cathodic overpotential during electrodeposition of cobalt nanowire arrays, Δ, was theoretically estimated by the difference between the cathode potential, , and the equilibrium potential, , calculated by the Nernst equation. On the other hand, the activation overpotential, Δ, was experimentally determined by the Arrhenius plot on the growth rate of cobalt nanowire arrays, , versus (vs.) reciprocal temperature, 1/. The ferromagnetic cobalt nanowire arrays with a diameter of circa (ca.) 25 nm had the preferred crystal orientation of (100) and the aspect ratio reached up to ca. 1800. The average crystal grain size, , of (100) peaks was estimated by X-ray diffraction patterns and was increased by decreasing the cathodic overpotential for cobalt electrodeposition by shifting the cathode potential in the noble direction. Axial magnetization performance was observed in the cobalt nanowire arrays. With increasing , coercivity of the film increased and reached up to ca. 1.88 kOe.
通过控制镀液温度和阴极过电位，研究了电沉积钴纳米线的晶体生长过程和铁磁性能。钴纳米线阵列电沉积过程中的阴极过电位Δ，理论上通过阴极电位与能斯特方程计算得到的平衡电位之差来估算。另一方面，活化过电位Δ通过钴纳米线阵列生长速率与倒数温度1/T的阿累尼乌斯图实验测定。直径约为25nm的铁磁钴纳米线阵列具有(100)择优晶体取向，长径比高达约1800。通过X射线衍射图谱估算(100)峰的平均晶粒尺寸，并通过向正向移动阴极电位降低钴电沉积的阴极过电位使其增大。在钴纳米线阵列中观察到轴向磁化性能。随着阴极过电位的增加，薄膜的矫顽力增大，最高可达约1.88kOe。
