单相钡铁氧体磁性材料的制备及磁性能研究

摘要

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(BaFe12O9) 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 He=372. 89kA/m.%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) (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) (Ba)的增大而变大,磁性能随n(Fe) (Ba)的增大而增强；当n(Fe) (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)(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.