环境温度对纳米掺镝铁氧体颗粒磁特性的影响

Effect of Ambient Temperature for Magnetic Properties of Dysprosium Ferrite Nanoparticles

在水相体系中用化学共沉淀法制备出纳米掺镝铁氧体磁颗粒,利用透射电镜(TEM)观察了磁颗粒的形貌,X-射线衍射仪(XRD)确定了产物的相结构,超导量子干涉仪(SQUID)测试了样品的磁性能。在318～378K范围内,研究了温度变化对产物磁特性的影响。TEM图片和XRD图谱分析表明,样品的形貌近似球形,具有立方尖晶石型结构,平均粒径约18 nm左右。对产物的磁性能研究显示,318K时的饱和磁化强度(MS)为183.4 mT,温度升高MS呈现出降低的变化规律;318K时的矫顽力(HC)为0.345 mT,温度升高HC减小,超顺磁性的特性增强。

Dysprosium ferrite nanoparticles were prepared by the chemical co-precipitation method in the water phase system.The morphologies of particles were observed by transmission electron microscope(TEM);The structure of products were characterized by X-ray diffraction(XRD)and the magnetic properties of sample were characterized by super-conducting quantum interference device(SQUID).The effect of various temperatures on magnetic properties of the products were investigated in the range of 318~378 K.The TEM image and XRD pattern analysis revealed that the shape of magnetic particles is approximately spherical,with the average size about 18nm and cubic spinel structure.Saturation magnetization(MS) of the products is 184.2mT at 318K,and MS of the magnetic nanoparticles decreases with increasing temperature.Coercitivity(HC) of sample is 0.345mT at 318K and it decreases with increasing temperature,whereas superparamagnetic becomes more obvious.