Ba掺杂及工艺对BiFeO_3体系结构和磁特性的影响  

Effects of Ba-doping and process conditions on the structure and magnetic properties of BiFeO_3 ceramics

作　　者：刘凤金[1] 陈水源[1] 黄志高[1] 

机构地区：[1]福建师范大学物理与能源学院,福建省量子调控与新能源材料重点实验室,福州350108

出　　处：《物理学报》2014年第8期255-260,共6页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2011CBA00200);国家自然科学基金(批准号:11004031;11004039);福建省自然科学基金(批准号:2012J01003);福建省新世纪优秀人才计划(批准号:JA12054)资助的课题~~

摘　　要：用溶胶-凝胶+快速热处理方法制备Bi_1-xBa_xFeO_3(BBFO-x,x=0,0.05,0.15)陶瓷材料,研究不同工艺条件和元素掺杂对样品的结构和磁特性的影响,实验结果表明,BBFO-x纯相样品制备工艺要求较高,在工艺条件为800℃下退火450s时,样品具有最好的结构及磁性能;X射线衍射测试表明,Ba元素替代会引起晶格畸变,但没有改变样品的宏观晶格结构;Raman光谱测试进一步证实了样品的纯相结构及Ba元素掺杂对样品结构的影响;此外,Ba元素替代有助于增强样品的磁性,其原因在于掺杂使得原有的长程反铁磁螺旋磁结构受到破坏,同时可能出现Fe离子价态变化,产生自旋耦合,从而在样品中表现出更大的宏观净磁矩,本工作可对开展这一单相多铁材料体系的微观结构以及磁电耦合效应的研究提供很好的实验基础。Multiferroic Bi1-xBaxFeO3 （named as BBFO-x, x = 0, 0.05, 0.15） are prepared by the sol-gel method through rapid thermal process. The effects of Ba-doping and process conditions on the structures and magnetic properties of the samples are investigated. The experimental results indicate that the process requirements of the pure BBFO-x samples are rigorous. The samples annealed at 800 ？C for 450 s possess the best structures and magnetic properties. X-ray diffraction results show that Ba-doping causes lattice deformations, but does not change the macroscopic lattice structures of the samples, which is further proved by the Raman spectra of the samples. Besides, Ba-doping is beneficial to enhancing the magnetization of the sample, which is attributed to both the destruction of long-rang antiferromagnetic spiral magnetic structure and the possible spin coupling resulting from the valent state change of the Fe ions. These achievements provide experimental foundation for further studying the microstructure and magnetoelectric coupling effect in such single phase multiferroics.

关 键 词：Ba掺杂BiFeO3 工艺条件 结构 磁特性 

分 类 号：O482.5[理学—固体物理]