溶胶-凝胶自燃烧法制备Ba(NiMg)0.2AlxFe11.4-xO19的结构与磁性能

以柠檬酸为络合剂,利用溶胶-凝胶自燃烧法制备了Ni、Mg、Al掺杂的M型钡铁氧体粉体(Ba(NiMg)0.2AlxFe11.4-xO19,x=0~0.4),利用X射线衍射仪、透射电子显微镜、综合物性测量系统等对样品结构与室温磁性能进行研究.结果表明,样品的物相组成与Al掺杂量有密切关系,当Al掺杂量x超过0.2时,产物中出现杂相α-Fe2O3,且杂相α-Fe2O3的含量随x值的增大而增加.在10kOe的外加磁场下,样品的饱和磁化强度(Ms)随x值的增大而降低,矫顽力(Hc)则随x值的增大先增大后减小,当x=0.2时,矫顽力达到最大值5644Oe,对应的饱和磁化强度为46emu/g.

Structure and Magnetic Properties of Ba(NiMg)0.2AlxFe11.4-xO19 Prepared by Sol-gel Auto-combustion Method

The Ni, Mg, Al co-doped M-type barium ferrite powders (Ba(NiMg)0.2AlxFe11.4-xO19, x=0-0.4 ) were prepared via a sol-gel auto-combustion method using citric acid as complexing agent .The structure and room-temperature magnetic properties of the as-samples were studied by X-ray diffraction ( XRD) , transmission electron microscope ( TEM) and physical property measurement system ( PPMS) . The results show that the phase constitutent of the samples is closely related to the amount of Al doping . When the x value exceeds 0.2, the impurity alpha-Fe2O3 appears in the products, and the content of alpha-Fe2 O3 increases with the increase of the amount of Al substitution .The saturation magnetization (10 kOe) decreases with the increase of x value, while the coercivity (Hc) value increases first and then decreases with the increase of x value, and the coercivity reaches the maximum value of 5644 Oe at x=0.2, corresponding to the saturation magnetization of 46 emu/g.