CoFe2O4超微粉末的磁性能及红外特性研究

采用溶胶-凝胶法制备CoFe2O4超微粉末，并经不同温度热处理，通过X射线衍射考察其结构特性，采用振动法测定其磁性能，运用红外漫反射光谱研究粉末红外特性的尺寸效应。结果表明：200℃以上的热处理开始促进粉末的长大和晶化过程，而且随着温度的升高，晶化程度增强，粉末粒径增大；CoFe2O4超微粉末的磁性与粉末的粒径大小有着密切的关系，磁饱和强度的最大值为57emu，矫顽力的最大值为1831Oe红外漫反射谱较好地反映粉末的尺寸效应，粉末粒径越小，漫反射函数值越大；当粒径达到一定尺寸时，红外漫反射的尺寸效应基本消失。

Research on Infrared Spectrum Character and Magnetic Property of CoFe2 O4 Nanoparticles

The sol-gel method was used for the synthesis of CoFe2O4 nanoparticles with different annealed temperatures. The structural, infrared and magnetic properties were measured using an X-ray diffractometer, diffuse reflectance spectroscopy and a viarating sample magnetometer separately. CoFe2O4 nanoparticles annealed at and above 200℃ begin growth and crystallization; the higher the temperature is, the stronger the crystallization is and the bigger the size of the particles, and as the an- nealed temperature increases the K-M values of infrared diffuse reflectance spectroscopy are more smaller and finally are indepandent to the size of particles and annealed temperature. The magnetic behanviour of CoFe2O4 nanoparticles is depanded on the annealed temperature.