单相钡铁氧体磁性材料的制备及磁性能研究

以硝酸钡、硝酸铁和柠檬酸为原料,采用溶胶-凝胶法制备了单相钡铁氧体(BaFe12O19)纳米粉体,并进一步研究了n(Fe)/n(Ba)、热处理温度对产物组成、形貌以及磁性能的影响。用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和振动样品磁强计(VSM)分别对样品的组成、形貌和磁性能进行了表征。实验结果表明,当煅烧温度不变时,样品的晶粒尺寸随着n(Fe)/n(Ba)的增大而变大,磁性能随n(Fe)/n(Ba)的增大而增强;当n(Fe)/n(Ba)不变时,样品的晶粒尺寸随着煅烧温度的升高而变大。当n(Fe)/n(Ba)=12时,在800℃煅烧2h得到单一晶型的钡铁氧体粉体。1000℃时样品的磁性能最佳,饱和磁化强度(Ms)为70.88A.m2/kg,矫顽力(Hc)为372.89kA/m。

Preperation and Magnetic Properties of Single-phase Barium Hexaferrite Nanoparticles

A precursor was prepared by sol-gel method with Ba(NO3)2,Fe(NO3)3·9H2O and C6H8O7·H2O as raw materials.Single-phase barium hexaferrite(BaFe12O19) nanoparticles were synthesized by calcining the precursor.And the influence of Fe/Ba molar ratio and calcination temperature on the crystal structure,morphology and magnetic properties were studied by X-ray diffraction(XRD),scanning electron microscope(SEM) and vibrating sample magnetometer(VSM).The experimental results show that the crystalline size and magnetic properties increase with the increasing of the Fe/Ba molar ratio when the calcination temperature is constant.On the other hand,the crystalline size grows with the increasing of the calcination temperature when Fe/Ba molar ratio is constant.Furthermore,when Fe/Ba molar ration is 12,the single-phase barium hexaferrite can be obtained after calcined at 800℃ for 2h.The barium hexaferrite sample calcined at 1000℃ exhibited the best magnetic properties: the saturation magnetization Ms=70.88A·m2/kg and Hc=372.89kA/m.