匀相沉淀法制备NiO纳米粒子及磁性研究

以Ni（N03）2·6H20和CO（NH2）2为原料，采用均相沉淀法制备尺寸为39．3nm的NiO粒子；以热重分析仪确定了前驱体的分解温度，X射线衍射仪、透射电镜等分析方法表征了产物的结构及形貌；利用振动样品磁强计对产物的磁性质进行了分析，磁滞回线显示：5K时产物具有铁磁性行为，矫顽力HC=899Oe；讨论了反应原料摩尔比、反应温度、反应时间等因素对制备NiO粒子粒径的影响，得到了优化实验条件：反应原料摩尔比（C／N）为5，反应温度为85℃，反应时间为4h，在此条件下，NiO收率达84％。

Preparation of NiO Nanoparticles by Homogeneous Precipitation Method and Magnetic Study

NiO nanoparticles with average particle size of 39.3 nm was prepared by a homogeneous precipitation method with nickel nitrate hexahydrate and urea. The decomposition temperature of the precursor was confirmed, by TGA.The structure and morphology of products were characterized by XRD, TEM, and the magnetic property of products were analyzed using a vibrating sample magnetometer （VSM）. The hysteresis loop at 5K shows a ferromagnetic behavior with a coercivity, Hc equal to 899 Oe; Various factors effects the particle size of NiO were discussed, such as the molar ratio of urea to Ni^2＋ ion （C/N）, reaction temperature, reaction time, and the best experimental condition were obtained. Yeild of NiO particle was 84%.