Point-defect-driven flattened polar phonon bands in fluorite ferroelectrics  

作　　者：Pu Ai Fengjun Yan Wen Dong Shi Liu Junlei Zhao Kan-Hao Xue Syed Ul Hasnain Bakhtiar Yilong Liu Qi Ma Ling Miao Mengyuan Hua Guangzu Zhang Shenglin Jiang Wei Luo Qiuyun Fu 

机构地区：[1]School of Integrated Circuits,Engineering Research Centre for Functional Ceramics of the Ministry of Education&Wuhan National Lab for Optoelectronics&Optical Valley Laboratory Huazhong University of Science and Technology,430074 Wuhan,China [2]Department of Physics,School of Science,Westlake University,Hangzhou,310024 Zhejiang,China [3]School of Optical and Electronic Information,Research Centre&Wuhan National Lab for Optoelectronics&Optical Valley Laboratory Huazhong University of Science and Technology,430074 Wuhan,China [4]Department of Electrical and Electronic Engineering,Southern University of Science and Technology,518055 Shenzhen,China [5]Shenzhen Huazhong University of Science and Technology Research Institute,518000 Shenzhen,P.R.China

出　　处：《npj Computational Materials》2023年第1期1120-1128,共9页计算材料学（英文）

基　　金：W.D.acknowledges the National Key Research and Development Plan(2021YFA1202100);the Nature Science Foundation of Hubei province(20223564/2022CFB595)and China(52202134);2021 Independent Innovation Fund-New Teacher Research Starting Fund of Huazhong University of Science and Technology(5003182109);the Innovation Fund of WNLO,2022 Shenzhen Central Leading Local Science and Technology Development Special Funding Program Virtual University Park Laboratory Project;Q.F.acknowledges the Natural Science Founda-tion of China(61971459);Shenzhen Technology Plan(JCYJ20190809095009521).

摘　　要：The scale-free ferroelectric polarization of fluorite MO_(2)(M=Hf,Zr)due to flat polar phonon bands are promising for nonvolatile memories.Defects are also widely introduced to improve the emergent ferroelectricity.However,their roles are still not fully understood at the atomic-level.Here,we report a significant effect of point-defect-driven flattening of polar phonon bands with more polar modes and polarization contribution in doped MO_(2).The polar phonon bands in La-doped MO_(2)(M=Hf,Zr)can be significantly flattened,compared with pure ones.However,the lower energy barrier with larger polarization of VO-only doped MO_(2) compared with La-doped cases suggest that VO and local lattice distortion should be balanced for high-performance fluorite ferroelectricity.The work is believed to bridge the relation between point defects and the generally enhanced induced ferroelectricity in fluorite ferroelectrics at the atomic-level and inspire their further property optimization via defect-engineering.

关 键 词：BANDS PHONON ferroelectric 

分 类 号：O48[理学—固体物理]