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

查看全文 作　　者：Pu [1]Ai;Fengjun [1]Yan;Wen [1]Dong;Shi [2]Liu;Junlei [3]Zhao;Kan-Hao [1]Xue;Syed Ul Hasnain [1]Bakhtiar;Yilong [1]Liu;Qi [1]Ma;Ling [3]Miao;Mengyuan [4]Hua;Guangzu [1]Zhang;Shenglin [1]Jiang;Wei [1]Luo;Qiuyun [1,5]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》索引2023年第1期,共9页 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