纳米絮状铁纤维的制备及性能测定

Preparation and Characterization of Nanometer Flocculent Iron Fiber

用化学气相热解制备纳米絮状铁纤维,通过X射线衍射仪、扫描电子显微镜、震动样磁强计、X射线能谱仪、微波矢量网络分析仪对材料的性能进行了表征。结果表明:制备的材料为体心立方结构的α Fe絮状纤维,研磨成微粉后,微观下仍然呈纤维状,自然降温的比饱和磁化强度(σs)为128～187emu·g-1,快速降温铁纤维的矫顽力(Hc)比自然降温的铁纤维高12倍;纤维的平均直径0 35μm,铁粒子的晶粒尺寸为6 85～15 18nm;在微波X波段有强吸收衰减作用,反射率小于-10dB,面密度为1 72～2 2kg/m2。

Nanometer flocculent iron fiber is prepared via chemical vapor thermal decomposition.The chemical structure,crystal style,morphology and magnetic properties of the prepared samples are examined with X-Ray diffraction,scanning electron microscopy and vibrating-sample magnetometer.It is shown that the prepared flocculent iron fiber,which remains as fiber in microstructure when ground into micro-powder,is a body-centered cube lattice of α-Fe.The fiber shows good performance with respect to saturation magnetization.Its specific saturation magnetization (σ_s) ranges from 128 emu·g^(-1) to 187 emu·g^(-1),while the coercive force of iron fiber under quick cooling is 12 times higher than that of spontaneously cooled iron fiber.The average diameter of the fiber is 0.35 μm,while the diameter of the crystal cell ranges from 6.85 nm to 15.18 nm.The absorber made of iron fiber with surface density in the range 1.72～2.2 kg/m^2 shows a reflectivity lower than -10 dB.