稀土正铁氧体YFeO_(3)的原子尺度离子占位解析及磁学性能研究  

Atomic observation of cation distribution in rare-earth orthoferrites YFeO_(3) and its magnetic property

作　　者：李红利 张军伟[1] 朱柳 毕开琦 关超帅 胡阳 陈斌 周霞 彭勇[1] LI Hong-li;ZHANG Jun-wei;ZHU Liu;BI Kai-qi;GUAN Chao-shuai;HU Yang;CHEN Bin;ZHOU Xia;PENG Yong(Electron Microscopy Centre of Lanzhou University,School of Physical Science and Technology Lanzhou University and Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education,Lanzhou Gansu 730000,China)

机构地区：[1]兰州大学电镜中心,兰州大学物理科学与技术学院磁学与磁性材料教育部重点实验室,甘肃兰州730000

出　　处：《电子显微学报》2021年第5期543-549,共7页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金面上项目(Nos.51771085,51571104,51801087,91962212,11874189);中央专项基金支持项目(No.lzujbky-2020-58)。

摘　　要：稀土正铁氧体YFeO_(3)具有独特的磁学性能,如自旋重新取向相变、高反铁磁转变温度和弱铁磁性,在磁感应器件等领域有良好的应用前景。YFeO_(3)优异的磁学性能与其晶体结构、离子具体占位和分布息息相关,所以在原子尺度上解析YFeO_(3)的微结构对理解和调控其磁学性能具有一定的指导作用。本文制备了单颗粒链YFeO_(3)纳米纤维,对其形貌、成分和结构进行了表征,得到该实验制备的YFeO_(3)为正交钙钛矿结构。进一步利用球差校正电镜的STEM技术系统地研究了阳离子的准确占位和长短程有序分布,在原子尺度上直观地解析了正交钙钛矿结构,结果显示每个堆积成纳米纤维的颗粒均为单晶,其晶向是随机的。随后对其磁学性质进行了研究,得到该材料具有大的矫顽力26772 Oe,在零场处存在弱铁磁相。Rare-earth orthoferrite YFeO_(3) has unique magnetic properties,such as spinreorientation phase transition,high antiferromagnetic transition temperature,the compensation effect,and weak ferromagnetism.It has good prospects in the fields of magnetic inductors and microwave devices.The excellent magnetic properties of YFeO_(3) are closely related to its crystal structure,specific occupancy and distribution of cation.Therefore,a clear microstructural analysis of the YFeO_(3) on the atomic scale plays a certain guiding role in understanding of its magnetic properties.In this work,electrospinning method is used to prepare YFeO_(3) nanofibers with single-particle-chain.The morphology,composition and structure of YFeO_(3) nanofibers are characterized,and the YFeO_(3) nanofibers prepared in this experiment are a typical orthogonal perovskite structure.Furthermore,systematical studies on the accurate distribution of cationsat the atomic scale by aberration-corrected scanning transmission electron microscopy(Cs-STEM).Each particle stacked into nanofibers is a single crystal structure,and their crystal orientationsare random.Moreover,the magnetic properties of the YFeO_(3) nanofibers are also studied and linked with its microstructure.

关 键 词：正交钙钛矿结构 球差校正电子显微镜 离子占位 磁学性能 

分 类 号：TG146.45[一般工业技术—材料科学与工程] TG115.215.3[金属学及工艺—金属材料]