摘要
In the present work,the nature of phase evolution of(1x)(Na_(0.5)Bi_(0.5))TiO_(3)-xSrTiO_(3)(NBT-xST)solid solutions with x of 0e0.6 is revealed by characterizing the dielectric and ferroelectric properties.Two unique dielectric anomalies associated with high-temperature nanoregions(PNRs)in the ergodic relaxor(ER)state and low-temperature PNRs in the nonergodic relaxor(NR)state are identified.Characteristic temperatures,including TB,TRT*,Tm,Td and TT*,are determined in fresh and poled states on the basis of the characteristics of the evolution of these two dielectric anomalies.The whole evolution of the transition from the NR state to the ER state is reflected by the temperature-dependent polarization versus electric field(P-E)hysteresis loops,i.e.,from the square loops,via the double-like loops,to the slim loops.The characteristic temperatures,including TP-N,TN-R and TR-dis,are determined by the characteristics of the evolution of P-E loops.Accordingly,a phase diagram of NBT-xST was constructed according to these characteristic temperatures.Most importantly,the relationship between polarization responses and heterogeneous polar phase coexistence has been established and a schematic diagram is given.This work will help to understand the phase evolution and its impact on the macroscopic properties of NBT and the associated NBT-based solid solutions.
基金
the National Natural Science Foundation of China(Grant nos.51672226,51772239)
the Fundamental Research Funds for the Central Universities(XJTU).
作者简介
Corresponding author:Gang Liu.E-mail addresses:liugang13@swu.edu.cn,an associate professor in the School of Materials and Energy at Southwest University.He received BEng and MEng degrees from the Northwestern Institute of Light Industry and Xi’an Jiaotong University,respectively.He received his PhD degree from the University of Birmingham(UB),UK in 2011.From 2011 to 2013,he was a postdoctoral research fellow in the Advanced Processing of Materials Laboratory at the UB.In 2013,he went back to China and became a faculty member of the Southwest University.His scientific research interests lie in ceramics and composites related with ferroelectric/piezoelectric/dielectric materials and their applications in transducer and energy storage devices.He has published more than 60 peer reviewed papers;Jia Dong,a postgraduate student in the School of Materials and Energy at Southwest University.In 2018,she received her bachelor degree in Materials Chemistry from the Sichuan Normal University.Her current research area is functional ceramics,including lead-free relaxation ferroelectric ceramics.She has published 2 reference papers as a co-author;Leiyang Zhang,s a PhD candidate in the School of Electronic Science and Engineering at Xi’an Jiaotong University.He received his bachelor degree in Inorganic Nonmetal Materials from the Changsha University of Science and Technology in 2016.He received his master degree in Materials Science from the Southwest University in 2019.His current research interests are focused on the lead-free relaxor ferroelectric materials and their application as dielectric energy storage devices and actuators.He has authored 1 referred paper and co-authored 5 referred papers;Corresponding author:Yan Yan,E-mail addresses:yanyan2013@swu.edu.cn,an associate professor in the School of Materials and Energy,Southwest University,China.She obtained MEng.degrees in Materials Physics and Chemistry from Xi’an Jiaotong University in 2007,and received her Ph.D degree from EPFL,Switzerland,in 2012.In May 2013,she joined Southwest University.Her research interests are focusing on functional ceramic materials and their applications including fuel cells,transducer and energy storage capacitors.Up to now,she has published more than 40 peer reviewed journal papers;Ruiyi Jing,a PhD candidate in the School of Electronic Science and Engineering at Xi’an Jiaotong University.She received her bachelor degree in Physics from the Henan Normal University in 2014.She obtained her master degree in Condensed Matter Physics from the Shaanxi Normal University in 2018.Her current research interests focus on lead-free relaxor ferroelectric materials and their applications in actuators.She has authored 3 referred papers and co-authored 10 referred papers;Corresponding author:Li Jin,E-mail addresses:ljin@mail.xjtu.edu.cn,a professor in the School of Electronic Science and Engineering at Xi’an Jiaotong University(XJTU),China.He received his BEng and MEng degrees in Electronics Science and Technology from the XJTU in 2003 and 2006,respectively.He received his PhD degree in Materials Science and Engineering from the Swiss Federal Institute of Technology in Lausanne(EPFL),Switzerland in 2011.Subsequently,he completed his postdoctoral research in the Ceramics Laboratory at EPFL.His interests include ferroelectric/electrostrictive/dielectric materials and their applications in actuators,energy storage devices and other electronic devices.He has coauthored more than 100 papers in peerreviewed journals with 3500t citations.One of his paper has been selected as the 100 Most Influential International Academic Papers in China,in 2014.He has received the First Prize of Natural Science Award by the Ministry of Education of China(2015).
