Mg1-xCaxFe2O4化合物的结构、磁性及交变磁场中的发热性能

Structure, Magnetism and Heating Properties in AC Magnetic Field of Mg1-xCaxFe2O4 Ferrites

采用固相反应法制备了Mg1-xCaxFe2O4(x=0,0.1,0.2,0.3,0.4)系多晶铁氧体,利用X射线衍射(XRD)法测定样品的物相结构,采用扫描电镜(SEM)观察样品形貌和分析其化学成分,用磁性测量仪对样品的磁性能进行了表征,并测定了交变磁场(频率为25kHz)中样品的发热性能。结果表明,Ca含量x=0~0.3时,样品均为单相立方尖晶石结构,当Ca含量x=0.4时样品呈现四方相;晶格常数和晶粒尺寸均随x值增加而逐渐增大,而饱和磁化强度(Ms)先增大后减小,矫顽力增大。当x=0.1时样品的Ms达到最大值16.37A·m^2·kg^-1,发热性能最佳。适量的Ca取代Mg可以提高Mg1-xCaxFe2O4铁氧体的磁性能及发热性能。

Aseries of Mg1-xCaxFe2O4 ferrites was prepared by a solid-state reaction method.The crystal structure,the morphology and chemical composition,the magnetic properties of the ferrites were investigated by using XRD,SEM and VSM,respectively.The heating performance was measured in an alternating magnetic field(25 kHz).The results show that the ferrites form the single-phase cubic spinel structure in the Ca content x between 0 and 0.3,while a tetragonal phase forms at x=0.4.The lattice constants,the coercivity and the grain sizes increase with x,while the saturation magnetization changes nonlinearly.The saturation magnetization(M s)reaches a maximum of 16.37 A·m^2·kg^-1 and the heating property is maximum atx=0.1.It turns out that appropriate amounts of Ca substitution for Mg could improve the magnetic and heating performance of the ferrites,which have potential application and promising approaches for tumor therapy.