不同粒径镍锌铁氧体纳米材料的磁性研究

Investigation of Magnetic Properties on NiZn-ferrite Nanoparticles with Different Diameters

利用液相催化的方法制备了尖晶石结构的Ni0.5Zn0.5Fe2O4铁氧体纳米颗粒，在反应过程中加入适当的助溶剂制备出了不同粒径的颗粒。XRD、TEM的测量结果表明生成物具有良好的尖晶石结构和结晶度，其粒径大小约为15～60nm。振动样品磁强计（VSM）对样品磁滞回线的测量表明随着磁性颗粒的增大，其饱和磁化强度也单调变大，饱和磁化强度的数值在40～65emu／g。随着磁性颗粒粒径的改变，其升温速率和达到的饱和温度在单畴附近达到最大。

The different size of Ni0.5Zn0.5Fe2O4 ferrites nanoparticles was prepared by refluxing method at relatively low temperatures （ 100℃ ）. The particle size was controlled by adding appropriate cosolvent during the reactions. The average size of Ni0.5Zn0.5Fe2O4 nanoparticles approximately was from 15 nm to 60 nm. The hysteresis loops showed that the saturation magnetization Ms of Ni0.5Zn0.5Fe2O4 particles increased from 40 emu/g to 65 emu/g as increasing the size of particles. A maximum dwell temperature and heating rate lay in the particle size 45 nm which is near the size of single domain.