磁场诱导下纳米镍纤维的制备及静磁性能

以乙二醇为溶剂,采用液相还原法成功制备了纤维状磁性金属镍。采用X射线衍射仪、扫描电子显微镜、能谱仪、透射电子显微镜与振动样品磁强计对样品进行了表征和分析,研究外加均匀磁场对磁性镍粉的形貌和性能的影响。结果表明,未加磁场时,反应产物为链状镍纤维,当外加均匀磁场为0.3T时,反应产物变成线状镍纤维。二者得到的产物均为面心立方金属镍。链状镍纤维的比饱和磁化强度和矫顽力分别为47A·m2/kg及15.52kA/m,而线状镍纤维随着反应物浓度的变化,比饱和磁化强度分别为49A·m2/kg、42A·m2/kg、42A·m2/kg,矫顽力分别为14.96kA/m、18.94kA/m及20.22kA/m。分析认为这种差异可能是镍纤维的粒径差异以及形状各向异性等所导致。

Field-induced preparation and magnetic properties of nanometer nickel fiber

Fibrous magnetic nickel powder was prepared by liquid reduction method in ethylene glycol. The effect of uniform magnetic field on the morphology and properties of magnetic nickel powder was studied. The crystal structure, morphology, composition , properties and so on were characterized by the X-ray diffraction (XRD), scanning electron microscope (SEM), energy disperse spectroscopy (EDS), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM), respectively. Results show that chain nickel fiber is obtained without magnetic field whilst linear nickel fiber in uniform magnetic field of 0.3 T. Fibrous magnetic powder is mainly composed by fcc structure. For as-prepared chain nickel fiber, saturation magnetization and coercivity were 47 emu/g and 195 Oe, whilst for linear nickel fiber. For reactants concentration of 0.01, 0.05 and 0.10 mol/L, samples were obtained with saturation magnetization of 49 emu/g, 42 emu/g, 42 emu/g,respectively and coercivity of 188 Oe, 238 Oe and 254 Oe, respectively, resulting from the difference of grain size and shape anisotropy of fibrous nickel powder.