电化学沉积并氧化法制备CoFe_2O_4纳米线阵列

CoFe_2O_4 Nanowire Arrays Prepared by Electrodeposition Method and Further Oxidization

用阳极氧化铝(AAO)模板,通过电化学沉积并氧化制备得到纳米线阵列.X射线衍射(XRD)结果显示纳米线由立方尖晶石CoFe2O4相构成,且无明显的择优取向.从透射电子显微镜(TEM)照片可看出,(AAO)模板内刚刚沉积的CoFe2纳米线结构疏松,而通过在空气气氛下的热处理,疏松的CoFe2纳米线转化为致密的CoFe2O4纳米线。当扩孔时间为40 min时,纳米线阵列的矫顽力最大,为1.9 kOe(外磁场平行于纳米线).进一步增加扩孔时间,矫顽力将下降。当外场垂直纳米线时,矫顽力随着扩孔时间的增加而单调减少.外场平行纳米线时,退磁曲线的方形度随着扩孔时间的增加而单调地从0.48减少到0.42;而外场平行纳米线时,方形度却从0.48增加到0.52。

By electrodeposition method and further oxidization,CoFe2O4 nanowire arrays within anodic aluminum oxide（AAO） templates were obtained.The XRD result indicated that the phase structure of the nanowires is cubic spinel-type,and they exhibit no preferred crystallite orientation.The TEM images showed that the CoFe2 nanowires electrodeposited within the templates are loose while they transformed into compact CoFe2O4 nanowires by thermal annealing in air.When the pore widening time is 40 min,the coercivity of the nanowire arrays reaches the maximum,1.9 kOe,with the applied field parallel to the nanowires.With further increase of the pore widening time,the coercivity decreases.When the applied field is vertical to the nanowires,the coercivity decreases with the pore widening time increasing,monotonously.The squareness ratio of the nanowire arrays with parallel applied field decreases from 0.48 to 0.42,monotonously,whereas the squareness ratio with vertical applied field increases from 0.48 to 0.52.