Fe-C纳米粉体的制备及特性

Preparation and characterization of Fe-C nanopowders

在50%CH4+20%H2+30%Ar,总压为2×104Pa的混合气氛下,用直流电弧等离子体蒸发纯Fe制备了Fe-C纳米粉体。用XRD、TEM、HRTEM、XPS、VSM、化学分析和氧含量分析等测试手段对粉体进行了分析。结果表明,在50%CH4+20%H2+30%Ar的混合气氛下制备的粉体形貌接近类球形,平均粒度50nm,粒子具有核壳结构,核为Fe-C,壳为4nm左右的碳膜。在温度低于300℃时,在50%CH4+20%H2+30%Ar气氛下制备的纳米粉体抗氧化性比在50%H2+50%Ar气氛下制备的强,饱和磁化强度为151.8Am2/kg,比在纯CH4气氛下制备的106.3Am2/kg大。

Fe-C nanopowders were prepared by DC arc plasma evaporating pure Fe in 50 % CH4 ＋ 20% HE ＋ 30% Ar atmosphere. The structure ,morphology,surface layer and oxidation resistance as well as magnetic behavior of the particles were studied using X-ray diffraction（XRD）, high-resolution transmission electron microscopy （HRTEM）, X-ray photoelectron spectroscopy （XPS）, chemical analysis and gas analysis as well as vibrating sample magnetometer. The results show that the nanoparticles mean particle sizes is 50nm and form in a coreshell strcturesur,which the core is F-C and the shell is carbon layer with 4nm thickness. The carbon layer prevents the particles from a further oxidation in air. The oxidization resistance of semples of 50 % CH4 ＋20 % HE ＋ 30% atmosphere is better than samples of 50% H2＋50%Ar atmosphere at the temperature below 300℃. The saturation magnetization of samples of 50 % CH4 ＋ 20 % HE ＋ 30 % atmosphere is 151.8Am^2/kg and higher than 106.3AmZ/kg of samples of CH4 atmosphere.