3d过渡金属掺杂对Bi_(0.8)Ba_(0.2)FeO_3陶瓷多铁性能的影响研究

Effect of 3 d Transition Metal Doping on Multiferroic Properties of Bi_(0.8)Ba_(0.2)FeO_3 Ceramics

采用传统固相烧结法制备多铁性Bi_(0.8)Ba_(0.2)Fe_(0.9)M_(0.1)O_3(M=Cr,Mn,Ti)陶瓷。X射线衍射图谱(XRD)表明该材料为纯相菱形钙钛矿结构,属于R3c空间点群。铁电测试结果表明,Bi_(0.8)Ba_(0.2)Fe_(0.9)Ti_(0.1)O_3陶瓷具有室温下的最大剩余极化值(2Pr)为0.64μC/cm^2和低频时的最小介电常数值(ε)为140。同时,所有样品的介电常数和介电损耗均随着频率的增加而降低且在高频时趋于稳定。磁性测试结果表明,Bi_(0.8)Ba_(0.2)Fe_(0.9)Mn_(0.1)O_3陶瓷具有室温下的最大剩余磁化值(2Mr)为1.46(A·m^2)/kg。显著的磁极化前后P-E回线变化被观察到,这直接说明了多铁性Bi_(0.8)Ba_(0.2)Fe_(0.9)M_(0.1)O_3(M=Cr,Mn,Ti)陶瓷中存在磁电耦合效应,且Bi_(0.8)Ba_(0.2)Fe_(0.9)Cr_(0.1)O_3样品具有最显著的磁电耦合效应值为5.8 m J/cm^3。

Multiferroic ceramics Bi0.8Ba0.2Feo.9g0.103 （M=Cr, Mn and Ti） were prepared by a conventional solid state reaction method. The pure phase with rhombohedral perovskite structure （space group R3c） was confirmed by the X-ray diffraction measurements for all samples. The results show that the maximum value of the remnant polarization （2Pr） and the minimum value of the dielectric constant at room temperature and low frequency for Bi0.sBao.2Feo.9Ti0.103 samples are 0.64 IxC/cm2 and 140, respectively. The dielectric constant and dielectric loss decrease with increasing frequency and then become nearly constant at higher frequency for all samples. The maximum value of the remnant magnetization （2Mr） for Bi0.sBa0.2Feo.gMno.lO3 samples at room temperature is 1.46 （A-m2）/kg by the M-H loops measurements. A remarkable change in the P-E loops is observed whether a bias DC magnetic field is applied or not, directly approving the existence of magnetoelectric coupling in multiferroic ceramics Bio.sBa0.2Fe0.gM0.103 （M=Cr, Mn and Ti）. And the maximum value of magnetoleectric coupling for Bio.sBao.2Feo,9Cro.lO3 samples is 5.8 mJ/cm3.