(La,Mn)共掺BiFeO_3材料的合成及性质研究

Synthesis and Properties of(La,Mn) Co-doped BiFeO_3

改善BiFeO3性能的有效途径,就是对其进行掺杂或与其他钙钛矿材料复合固熔。由于稀土元素与Bi的化合价相同,较容易取代Bi离子,而且Mn,Cr的掺杂又可提高BiFeO3的磁性。通过掺杂,采用溶胶-凝胶法合成了Bi1-xLaxFe0.8Mn0.2O3材料(x=0.3,0.35,0.4),用XRD测试了其晶体结构,通过原子力显微镜测试其表面形貌。通过对复合陶瓷(Bi1-xLaxFe0.8Mn0.2O3)的磁性能、介电性能和磁电耦合性能的研究,作出复合陶瓷的M-H磁滞回线。结果显示:随着La掺杂量的增加,原胞体积变小,x=0.4时,颗粒进一步细化;磁滞回线显示,随着La掺杂量的增加,剩磁逐渐增大,磁性能得到一定的改善,磁电耦合性能进一步提高,但介电性能有所减弱。

It is the effective way to improve the function of BFO that the BFO was doped or melted with other per- ovskite material. The Bi atom is substituted easily by rare-earch metal atom because their valence are same, and the magnetism of BFO can be increased by doping the Mn and Cr atom, So Bi1-xLaxFe0.8Mn0.2O3 （x =0.3, 0.35, 0. 4） was composed by Sol-Gel in this paper. The structure and the surface morphologie were investigated by XRD, AFM respectively. The hysteresis loop （ M-H loop） of the composite ceramic was obtained by searching magnetism, dielectric properties, and ME effect of the composite ceramic. The result manifested that the volume of the primitive cell decreased with the amount of the La atom doped increased, the particle of the composite ceramic was smallest when the x = 0.4 which x was in number 0.3, 0.35, 0.4, as well as the remanence of the composite ceramic was increase gradually, and the magnetism properties was properties was weakened. improved, ME effect was also increased, but the dielectric