La和Nb共掺提高BiFeO_3的磁学性能  

Enhanced Magnetic Properties of Bismuth Ferrite by La and Nb Co-doping

作　　者：邓施列 冼慧敏 陈熹 唐玲云 张弜 毛忠泉 DENG Shilie;XIAN Huimin;CHEN Xi;TANG Lingyun;ZHANG Jiang;MAO Zhongquan(Department of Physics,South China University of Technology,Guangzhou 510640)

机构地区：[1]华南理工大学物理与光电学院,广州510640

出　　处：《材料导报》2018年第2期176-179,188,共5页Materials Reports

基　　金：国家自然科学基金(11304098;11504113)

摘　　要：采用溶胶-凝胶法成功制备了Bi_(1-x)La_xFe_(0.99)Nb_(0.01)O_3(x≤0.25)纳米颗粒样品,并研究了La和Nb共掺对BiFeO_3样品的晶体结构、晶粒尺寸和磁学性质的影响。根据X射线衍射及Rietveld精修结果可知,所有样品都保持R3c空间结构,且Fe-OFe键角随着La掺杂量的增加而减小。XPS测试结果表明,La和少量Nb共掺不会引起样品中Fe^(3+)和Fe^(2+)含量的明显变化。磁性测量发现剩余磁化强度强烈依赖于La掺杂量x。La掺杂影响着反向旋转的FeO_6八面体结构变化,而Nb离子掺杂会导致样品晶粒细化。共掺BiFeO_3的磁性增强是两种影响机制协同作用的结果。In the present work,a series of Bi 1-x La x Fe 0.99 Nb 0.01 O 3(x≤0.25)nanopowders were prepared by sol-gel method,in order to investigate the crystalline structure,grain size and magnetic properties of La and Nb co-doped BiFeO 3 nanopowders.All samples are consistent of an R3c rhombohedral structure with decreasing Fe-O-Fe bond angles as the La concentration increases,according to XRD and Rietveld refinement.The XPS data demonstrate that La and Nb co-doping do not change the ratio of Fe 3+to Fe 2+in doped BFO system.The remnant magnetization was found to depend markedly on La doping amount(x).It is shown that the La-doping dominates the anti-rotation of the FeO 6 octahedral,while the low doping of Nb results in the refinement of the grains.Both mechanisms would give rise to the magnetization enhancement in bismuth ferrite.

关 键 词：铁酸铋 掺杂 磁学性能 晶格畸变 

分 类 号：O76[理学—晶体学]