钇掺杂M型锶铁氧体的结构与磁性能研究

Research of Structure and Magnetic Properties of Yttrium-doped M-type Strontium Ferrite

采用固相烧结法于1150℃保温烧结3h制备了钇掺杂的M型锶铁氧体SrYxFe(12-x)O19(x=0,0.25,0.5,0.75,1.0)预烧料,再将预烧料在取向磁场下压制成型后于1295℃保温3h烧结成磁体。用X射线衍射仪对烧结磁体的相结构进行分析,用扫描电子显微镜对烧结磁体的表面形貌进行分析,用磁性能测试仪测试烧结磁体的磁性能。结果表明,随着钇掺杂量的增加,晶格常数a呈现非常微小的变化,c缓慢增大,a/c先增大后减小,晶体X射线密度dX-ray近似呈线性增加。SEM分析表明制备的磁体具备典型的六方晶系结构的形貌特征。磁性能研究表明随着钇掺杂量的增加,剩磁Br单调增加,内禀矫顽力Hcj、最大磁能积(BH)max与磁感矫顽力Hcb的变化规律均为先增大后减小;当x=1.0时,剩磁Br达到最大值420.7mT,但内禀矫顽力Hcj随之变为最小值;当x=0.75时Hcj达到最大值323.7kA·m-1,同时剩磁Br达到了410.4mT。

Yttrium-doped M-type strontium ferrite SrYxFe（12-x）O19 （x=0,0.25,0.5,0.75,1.0） calcined materials were prepared by solid-phase sintering method at 1150 ℃ for 3 h.Then the calcined materials were pressed for magnets under the condition of oriented magnetic field and sintered at 1295 ℃ for 3 h.X-ray diffraction,scanning electron microscope and magnetic tester were used to analyze the phase structure of the sintered magnets,the surface morphology of the sintered magnet and the magnetic properties of the sintered magnets respectively.The results showed that with the increase of yttrium-doped,the lattice constant a changes little,c increases slowly,a/c first increases and then decreases,crystal X-ray density dx-ray approximation increases linearly.SEM showed that the magnet has prepared a typical hexagonal structure morphology.Magnetic studies showed that with the doping of yttrium increase,the remanence Br increasing monotonically,intrinsic coercivity Hcj and maximum energy product （BH）max and coercivity magnetic induction H,first increasesd and then decreased.When x=1.0,the remanence Br reach maximum with 420.7 mT,but the intrinsic coercivity Hcj decreased to a minimum value; when x=0.75,the intrinsic coercivity Hcj have a maximum value of 323.7 kA · m^-1,and the remanence Br reached 410.4 mT.