NiFe2O4纳米线阵列的制备与磁性

在氧化铝模板的纳米孔洞中, 用电化学的方法沉积铁镍合金纳米线，经过550℃30h氧化处理 , 成功制备出 NiFe2O4纳米线阵列. 分别用扫描电子显微镜 (SEM) 、透射电 子显微镜 (TEM) 、x射线衍射仪 (XRD) 和振动样品磁场计 (VSM) 对样品的形貌、晶体结构 和磁学性质进行了表征测试. SEM和TEM观察结果显示氧化铝模板的孔洞分布均匀，孔心距约 为110nm; 纳米线的直径约为70nm. XRD显示纳米线阵列的物相结构为NiFe2O4; VSM测试结果表明，NiFe2O4纳米线阵列膜的易磁化方向垂直于膜面. 当垂直 磁化时磁滞回线的矩形比约为05，矫顽力为41×103A/m，比氧化处理前的铁镍合金 纳米线阵列都有显著提高.关键词：纳米线Ni Fe2O4矫顽力

Fabrication of NiFe2O4 nanowire arrays and its magnetic properties

Arrays of NiFe2O4 nanowires were prepared by using porous anodic al uminum oxide(AAO) membrane as the template. For the preparation of the ferrite n anowires, Ni_Fe alloy nanowires were electrodeposited into the pores of the AAO membranes. The atomic ratio is about Ni∶Fe=1∶2 which can be detected by engerg y dispersive spectroscopy. X-ray diffraction study showed the pure phase of NiFe 2O4 after anodization. SEM and TEM studies showed the diameters of t he pores and the nanowires are all about 70nm. The vibrating sample magnetometer studies of the nanowire arrays showed the anisotropic magnetic properties befor e and after anodization. Coercivity and squareness ratio have been improved appa rently in the NiFe2O4 nanowires arrays.