Homogenous Sn-doped K(Ta,Nb)O_(3) single crystals and its high piezoelectric response  

作　　者：Fengying Liu Yuanyuan Zhang Limei Zheng Gang Tian Juan Du Le Zhao Xudong Chen Xuping Wang Minglei Zhao 

机构地区：[1]School of Physics,Shandong University,Jinan,250100,China [2]Advanced Materials Institute,Qilu University of Technology(Shandong Academy of Sciences),Jinan,250014,China [3]College of Materials Science and Engineering,Liaocheng University,Liaocheng,252059,China [4]School of Electronic and Information Engineering Department of Physics,Qilu University of Technology(Shandong Academy of Sciences),Jinan,Shandong,250353,China

出　　处：《Journal of Materiomics》2022年第3期702-709,共8页无机材料学学报（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(Grants Nos.52072218,and 52072189);Natural Science Foundation of Shandong Province,China(ZR2020KE019);the Project for Introduced Innovation Team in Jinan,China(2020GXRC037);the Primary Research&Development Plan of Shandong Province,China(No.2019JZZY010313).REFERENCES.

摘　　要：Perovskite K(Ta,Nb)O_(3)(KTN)single crystal has drawn great interests for its outstanding electro-optic performance and excellent piezoelectric response.However,growth of compositionally uniform KTN single crystals has always been a great challenge for the great segregation difference between Nb and Ta.In this work,we propose a thermal field optimization strategy to resolve this challenge.Homogenous Sn doped KTN(Sn:KTN)single crystal with significantly reduced composition gradient(0.003 mol/mm,1/4 e1/8 of other KTN system),minimal TC variation(13℃)and excellent piezoelectric and dielectric response(d_(33)=373 pC/N andε^(T)_(33)=5206)has been successfully achieved.We found that the functional properties of Sn:KTN were greatly affected by the near-room temperature tetragonal-cubic phase transition.From the intrinsic aspect,longitudinal lattice deformation becomes much easier,resulting in maximum piezoelectric(d^(*)_(33)),dielectric(ε^(T*)_(33)),elastic(s^(E*)_(33))and electromechanical coupling(k^(*)_(33))coefficients along polar direction[001]_(C).From the extrinsic aspect,both domain wall density and domain wall mobility are greatly improved for the reduced lattice distortion,which also contribute a lot to the functional properties.This work provides a simple and practical route for designing and growing high quality crystals,and more importantly,reveals the fundamental mechanism of the phase transitions/boundaries on the functional properties.

关 键 词：Low composition gradient High piezoelectric response PS extension/contraction T-C phase transition Sn:KTN 

分 类 号：O7[理学—晶体学] TM8[电气工程—高电压与绝缘技术]