NiFe_2O_4纳米粉末的制备及磁性研究

以硝酸铁、硝酸镍以及柠檬酸为原料,采用凝胶-热分解法制备了N iFe2O4纳米粉末。利用X射线衍射确定了粉体的相结构、比表面积和晶格常数,扫描电子显微镜(SEM)观察了颗粒的形貌,振动样品磁强计(VSM)测量样品的磁性能。结果表明:所制备的样品均为尖晶石结构,颗粒粒径为36nm~68nm,且颗粒的粒径随着热处理温度的升高而增大,样品的比饱和磁化强度最大可达54.63 emu/g。同时,文章也对反应的动力学原理进行了研究,得出N iFe2O4纳米颗粒形成的活化能为15.8kJ/mol。

Preparation and magnetic properties of NiFe2O4 nanoparticles

The nanoparticles NiFe2O4 were successfully prepared by Gel-thermal decomposition method from raw materials of Fe nitrate salts,Ni nitrate salts and citric acid.The structure,specific surface area and lattice constant of the NiFe2O4 nanoparticles were characterized by X-ray diffraction(XRD);The morphologies of NiFe2O4 powders were observed by the scanning electron microscope(SEM) and the magnetic properties of NiFe2O4 nanoparticles were characterized by Vibrating Sample Magnetometer(VSM).The results show that the products are pure NiFe2O4 and the average crystal size of all spinel NiFe2O4 was 36～68nm,What is more,the crystal size increases with the heat treatment temperature increase.The specific saturation magnetization of NiFe2O4 nanoparticles can achieve 54.63emu/g.Simultaneity,the article also studied the kinetics of the thermal decomposition process of the precursor and obtained the activation energy of NiFe2O4 nanoparticles formation during thermal treatment was about 15.8kJ/mol.