Bi_(0.5)Na_(0.5)TiO_(3)-BaTiO_(3)(BNT-100xBT)ceramics are promising candidates for piezoelectric applications.The correlation between their structure and piezoelectric properties has attracted considerable interest.He...Bi_(0.5)Na_(0.5)TiO_(3)-BaTiO_(3)(BNT-100xBT)ceramics are promising candidates for piezoelectric applications.The correlation between their structure and piezoelectric properties has attracted considerable interest.Herein,the structures of 6BT and 7BT with distinct piezoelectricity are investigated via in-situ synchrotron X-ray diffraction and transmission electron microscopy.It is found that although both compositions present morphotropic phase boundary(MPB)features with coexisting R3c and P4bm phases,their refined structures are significantly different.6BT is composed of the R3c phase with a small P4bm fraction after electrical poling,while 7BT presents comparable fractions of the two phases.Less pronounced structure distortion and oxygen octahedral tilting occur in 7BT,which favor the phase transformation,resulting in an enhanced piezoelectricity.This enhancement driven by structural flexibility is elucidated by phenomenological analysis.These results demonstrate that the design of high piezoelectricity at MPBs should consider not only the phase-coexisting states but also the refined crystal structure.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.22075014,12004032,51972028 and 22001014)China National Postdoctoral Program for Innovative Talents(BX20200044 and BX20200043)+2 种基金China Postdoctoral Science Foundation(2021M690366)the Fundamental Research Funds for the Central Universities,China(Grant Nos.06500162,06500145,and FRF-MP-20-40)a US Department of Energy(DOE)Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No.DEAC02-06CH11357.
文摘Bi_(0.5)Na_(0.5)TiO_(3)-BaTiO_(3)(BNT-100xBT)ceramics are promising candidates for piezoelectric applications.The correlation between their structure and piezoelectric properties has attracted considerable interest.Herein,the structures of 6BT and 7BT with distinct piezoelectricity are investigated via in-situ synchrotron X-ray diffraction and transmission electron microscopy.It is found that although both compositions present morphotropic phase boundary(MPB)features with coexisting R3c and P4bm phases,their refined structures are significantly different.6BT is composed of the R3c phase with a small P4bm fraction after electrical poling,while 7BT presents comparable fractions of the two phases.Less pronounced structure distortion and oxygen octahedral tilting occur in 7BT,which favor the phase transformation,resulting in an enhanced piezoelectricity.This enhancement driven by structural flexibility is elucidated by phenomenological analysis.These results demonstrate that the design of high piezoelectricity at MPBs should consider not only the phase-coexisting states but also the refined crystal structure.
