核壳型碳铁纳米粉体的制备及磁性能研究

Preparation and Magnetism Research of Carbon Coated Nano Iron Nanoparticles with Core-shell Structure

采用直流碳弧法制备碳包铁纳米粒子,用透射电子显微镜(TEM)、X射线衍射仪(XRD)对产物的形貌和尺寸、物相结构组成进行分析,并在真空和氮气气氛下在200～800℃对制备的碳包铁纳米粒子进行热处理,用振动样品磁强计测量处理前后的碳包铁纳米粒子的剩磁强度、矫顽力和饱和磁化强度。结果表明,碳包铁纳米粒子的磁滞回线显示出较好的超顺磁特性;剩磁强度、矫顽力和饱和磁化强度随着粉体中铁含量的增加而增大。对碳包铁纳米粒子进行热处理,其磁性能随温度的升高首先改善,温度进一步升高又逐步劣化。在450℃退火,粉体磁性能最佳。

Carbon coated iron nanoparticles are produced by the DC carbon discharge method. The structure, size distribution, phase composition and magnetic properties of the particles are investigated by using TEM, XRD and VSM, and annealing carbon coated iron nanoparticles at 200℃ to 800℃. The magnetic hysteresis loops of the particles show a good superparamagnetic characteristic. Mr, Ms and Hc are increased with the increase of Fe content. The result of annealing show that Hc reaches a maximum at 450℃.