Ferroelectric domains and phase transition of sol-gel processed epitaxial Sm-doped BiFeO_(3)(001)thin films  

作　　者：Zhen Zhou Wei Sun Zhenyu Liao Shuai Ning Jing Zhu Jing-Feng Li 

机构地区：[1]State Key Laboratory of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing,100084,China [2]National Center for Electron Microscopy in Beijing,State Key Laboratory of New Ceramics and Fine Processing,Key Laboratory of Advanced Materials(MOE),School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Journal of Materiomics》2018年第1期27-34,共8页无机材料学学报（英文）

基　　金：This work was supported by the National Nature Science Foundation of China(Grants no.51332002,11374174,51390471,51527803 and 51221291);the Ministry of Science and Technology of China under Grant 2015CB654605,National 973 Project of China(2015CB654902);National key research and development program(2016YFB0700402);This work made use of the resources of the National Center for Electron Microscopy in Beijing and the BL14B1 beamline of the Shanghai Synchrotron Radiation Facility under project no.14SRBL14B10499.

摘　　要：BiFeO_(3),a room-temperature multiferroic material,has recently been increasingly applied as a potential lead-free piezoelectric material due to its large piezoelectricity achieved by doping.In this work,12%Smdoped BiFeO_(3)epitaxial thin films were fabricated on Nb-doped SrTiO_(3)(001)single crystal substrates via sol-gel method.The epitaxy was verified by reciprocal space mapping(RSM)and transmission electron microscope(TEM).The TEM results indicated the coexistence of R3c and Pbam phases in the film.The domains and piezoelectric properties from room temperature to 200℃were characterized by piezoresponse force microscopy(PFM).Domains became active from 110℃to 170℃,and domain configurations changed obviously.A partially fading piezoresponse indicated the emergence of antiferroelectric Pbam.The in-situ domain analysis suggested that the phase transition was accompanied by domain wall motion.Switching spectroscopy PFM(SS-PFM)was further conducted to investigate the piezoresponse during the phase transition.Anomalous responses were found in both ON and OFF states at 170℃,and the film exhibits typical antiferroelectric behavior at 200℃,implying that the completion of phase transition and structure turned to the Pbam phase.This work revealed the origin of the high piezoresponse of Sm-doped BiFeO_(3)thin films at the morphotropic phase boundary(MPB).

关 键 词：BiFeO_(3) Piezoresponse force microscopy Morphotropic phase boundary Phase transition ANTIFERROELECTRIC 

分 类 号：O48[理学—固体物理]