Eu,Co共掺杂对BiFeO_3陶瓷的介电性能、磁性能及磁电耦合效性的影响  

Effect of Eu and Co Doping on the Dielectric Properties,Magnetic Properties and Magneto-electric Coupling of BiFeO_3 Ceramics

作　　者：宋桂林[1,2] 马桂娟[1] 张卉[1] 苏健[1] 陈晨[1] 常方高[1,2] 

机构地区：[1]河南师范大学物理与信息工程学院,新乡453007 [2]河南省光伏材料重点实验室,新乡453007

出　　处：《人工晶体学报》2013年第11期2351-2358,共8页Journal of Synthetic Crystals

基　　金：国家自然科学基金(60571063);河南省重点科技攻关项目(122300410203);河南河南省教育厅自然科学研究计划(2011A140014)

摘　　要：采用快速液相烧结法制备Bi1-xEuxFe1-yCoO3（x=0、0．01、0．05、0．1；y=0、0．01、0．05、0．1）陶瓷样品，研究Eu、Co共掺杂对BiFeO3介电性能、铁磁性和磁电耦合效应的影响。利用x射线衍射仪对晶体结构进行表征，结果表明：所有样品的主衍射峰与纯相BiFeO3相吻合且具有良好的晶体结构。当co掺杂量大于0．05时，Bi1-xEuxFe1-yCoyO3发生结构相变。当f=1000Hz时，Bi0.99Eu0.01Fe0.99Co0.01O3样品的介电常数是BiFeO3的12倍，而介电损耗最小。磁测量表明：室温下，除了BiFeO3和Bi1-xEuxFe0.99Co0.01O3以外，所有样品具有较强的铁磁特性。在20kOe磁场作用下，Bi1-xEuxFe1-yCoyO3样品呈现饱和的磁滞回线，Bi0.9Eu0.1Fe0.99Co0.1O3样品的剩余磁化强度（Mx=0．984emu／g）是BiFeO3的328倍。在外加磁场（0—0．4kOe）作用下，样品的磁电耦合效应（ME）随着Eu3＋和Co3＋掺杂量的增加而增大，Bi0.95Eu0.05Fe0.95Co0.05O3呈现较强的磁电耦合效应，在4．5kOe磁场的作用下，其ME值已达到4．37％。样品磁性增强的主要是Eu3＋的4f电子与Fe3＋或Co3＋的3d电子自旋相互作用及样品中存在局域的Fe-O—Co磁耦合两者共同作用的结果。Multiferroic Bi1-x EuxFe1-y CoyO3 （X= 0, 0. 01, 0. 05, 0. 1; y =0, 0. 01,0. 05, 0. 1 ） ceramics were prepared by rapid liquid phase sintering method. The dielectric properties, magnetic and magnetodielectric were investigated by Eu and Co doping BiFeO3. The structure and morphology of BiFeO3 ceramics have been characterized by X-ray diffraction （XRD）. The results showed that all the peaks for Bi1-xEuxFe1-yCoyO3 samples can be indexed according to the crystal structure of pure BiFeO3. And X-ray diffraction analysis revealed a phase transition in Eu, Co co-doped BiFeO3 ceramics when y is larger than 0.05. The dielectric constant （εr） of Bi0.99Eu0.01Fe0.99Co0.01O3 （ εr = 1798 ） at 1 kHz was nearly 12 times larger than that of pure BiFeO3 （63 = 150） ceramic while the dielectric loss （tg δ） was smallest all of samples. The magnetic measurements show that all samples possess strong ferromagnetism at room temperature except BiFeO3 and Bi1-xEuxFe0.99Co0.01 03 which are weakly ferromagnetic. Under the effect of external magnetic field of 20 kOe, the Mr of Bi0.9Eu0.1Fe0.gCo0.103 was 328 times of that of BiFeO3, The values of ME effect of BiFeO3 samples can be enhanced by doping Eu3＋ and Co3＋ with applied magnetic field increasing from 0 Oe to 4.5 kOe. Maximum ME effect as high as 4.37% observed at x = 0. 05, y = 0. 05 （ Bi0.95 Eu0.05 Fe0.95 Co0.05 03 ）. The ferromagnetism of Bil_x EuxFe0.99 Coo.m 03 samples can be enhanced by doping Eu3＋ and Co3＋. The interaction between 4f electric of Eu3＋ and 3d electric of Fe3＋ spins or Co3 ＋ spin changed and Fe-O-Co magnetic coupling.

关 键 词：BIFEO3 介电性能 磁滞回线 磁电耦合 

分 类 号：O469[理学—凝聚态物理]