缓冲层对铁电PbTiO3薄膜微结构的影响  

The Effect of Structural Defects in Buffer Layer on the microstructures in Ferroelectric PbTiO3 films

作　　者：刘嘉琦 冯燕朋 朱银莲[1] 曹毅 刘楠[1,2] 石彤彤 唐云龙[1] 马秀良 LIU Jia-qi;FENG Yan-peng;ZHU Yin-lian;CAO Yi;LIU Nan;SHI Tong-tong;TANG Yun-long;MA Xiu-liang(Institute of Metal Research,Chinese Academy of Sciences,Shenyang Liaoning 110016;University of Science and Technology of China,School of Materials Science and Engineering,Shenyang Liaoning 110016;Songshan Lake Materials Laboratory,Dongguan,Guangdong 523808;School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou Gansu 730050)

机构地区：[1]沈阳材料科学国家研究中心,中国科学院金属研究所,辽宁沈阳110016 [2]中国科学技术大学,材料科学与工程学院,辽宁沈阳110016 [3]松山湖材料实验室,广东东莞523808 [4]兰州理工大学材料科学与工程学院省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050

出　　处：《电子显微学报》2020年第6期673-679,共7页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(Nos.51971223,51671194,51922100).

摘　　要：缓冲层作为一种调控铁电薄膜畴组态和引入新的微结构的有效手段被广泛采用。本文在大拉应变KTaO3衬底上生长了LaNiO3/PbTiO3多层膜,利用透射电子显微学方法,对该薄膜体系中的缺陷结构及其与铁电畴的交互作用进行了细致地研究。结果表明,由于巨大的界面失配,LaNiO3层中形成密集的Ruddlesden-Popper型层错,该层错经由LaNiO3/PbTiO3异质界面诱导PbTiO3中形成贯穿型的层状缺陷,这种缺陷的形成对PbTiO3内部畴结构有着一定的影响。利用电子能量损失谱,发现层状缺陷处Ti元素的价态有所降低,可能源于LaNiO3与PbTiO3之间的电荷传递。这一结果揭示了中间缓冲层对PbTiO3薄膜内部微结构产生重要的影响,同时也为铁电畴的调控提供了新的途径。Buffer layer is widely used as an effective method to modulate domain configuration and introduce new microstructures in ferroelectric thin films.In this paper,a LaNiO3/PbTiO3 multilayer film was grown on the large tensile strain KTaO3 substrate.The defect structures of the film system and the interaction between defects and ferroelectric domains were investigated by using transmission electron microscopy(TEM).The results show that dense Ruddlesden-Popper(R-P)faults are formed in the LaNiO3 layer due to the large lattice mismatch,which induces the formation of penetrating layered defects in PbTiO3 across the LaNiO3/PbTiO3 heterogeneous interface.The formation of such defects has a certain influence on the internal domain structure of PbTiO3 layer.It was further found that the valence state of Ti ions decreased at the layered defect by using electron energy loss spectrum,which might be attributed to the charge transfer between LaNiO3 and PbTiO3 layers.These results reveal that the intermediate buffer layer has an important effect on the microstructure of PbTiO3 films and provides a new way to modulate the ferroelectric domain configurations.

关 键 词：钛酸铅薄膜 缓冲层 微结构 像差校正透射电子显微学 

分 类 号：TG115.215.3[金属学及工艺—物理冶金] O77[金属学及工艺—金属学]