摘要
Correlated phase and microstructural evolution are systematically investigated by electron microscopies in Sr-deficient Sr(Ti,Nb)O_(3)(STNO)thermoelectric ceramics incorporated with different fraction of reduced graphene oxide(RGO).It is found that while no impurity except for very few Ti_(3)O_(5) precipitates are observed in monolithic STNO,the Nb-enriched rutile TiO_(2) appears in RGO/STNO composites.With increasing RGO content,the amount of precipitates increase at first and then decrease when RGO content becomes high,which can be ascribed to the formation of local Magneli phase.In addition,the energy-dispersive X-ray spectra combined with cathodoluminescence characterization indicates that the variation of Sr deficiency experiences the opposite trend with respect to the precipitates content.These findings clearly reveal the unique reducing effect of RGO on the microstructure of doped SrTiO_(3) with Sr deficiency,which can greatly facilitate the design of perovskite based thermoelectric materials of hierarchical structure.
基金
supported by the National Natural Science Foundation of China[Grant numbers 51532006,51432004]
State Administration of Foreign Experts Affairs of China,111 project[Grant number D16002]
the Opening Project of Key Laboratory of Inorganic Functional Materials and Devices,Chinese Academy of Sciences(Grant number KLIFMD201804).
作者简介
Miss Jia Li received her bachelor’s degree in College of Materials Science and Engineering from Yancheng institute of Technology.She is now a graduate student of Material Genome Institute at Shanghai University,mainly working on microstructure of graphene/SrTiO3 ceramics and their microstructure-thermoelectric property relationships;Mr.Cao Wu received his bachelor’s degree from Anhui Chaohu University.He is now a graduate student of Materials Physics and Chemistry at Donghua University,mainly working on the preparation and thermoelectric properties of graphene/SrTiO3 ceramic composites;Mr.Jilong Huang is pursuing a Ph.D.in material processing engineering at DongHua University.He received his M.S.degree from Shanghai University of Engineering Technology.His current research focuses on study of oxide thermoelectric materials for high temperature applications,and low-dimensional materials such as graphene and molybdenum disulfide to enhance the thermoelectric performance of oxide composites materials;Corresponding author:Dr.Juanjuan Xing received her Bachelor’s degree from Zhengzhou University and Ph.D.from Shanghai Institute of Ceramics,Chinese Academy of Sciences.She had worked as a postdoc in National Institute for Materials Science,Japan.Now she is working in the School of Material Science and Engineering&Materials Genome Institute at Shanghai University.Her research focuses on the microstructure and interface of functional ceramics.E-mail addresses:xingjuanjuan@shu.edu.cn;Corresponding author:Prof.Yuchi Fan received his Bachelor’s degree from Wuhan University of Technology and Master’s degree from Shanghai Institute of Ceramics,Chinese Academy of Sciences.After receiving PhD in Materials Processing from Tohoku University(TU),he continued to work as JSPS fellow in Prof.Akira Kawasaki’s laboratory at TU.Then he joined Prof.Tatsumi Ishihara’s laboratory at Kyushu University as a research fellow.Now he is a full-professor at Donghua University.His research focuses on the design and preparation of two-dimensional materials based ceramic composites applied for thermoelectrics,microwave absorbing materials and other ceramic matrix composites with incorporated structural and functional properties.yuchifan@dhu.edu.cn;Miss Qingqiao Fu received her bachelor’s degree in college of chemistry from Shandong Agricultural University in 2017.She is now a PhD candidate of Materials Science and Engineering at Shanghai University,mainly working on microstructure of co-doping SrTiO3 thermoelectric material;Dr.Ying Jiang received her Bachelor’s and Doctor’s degrees from Zhejiang University.Now she is working in Materials Genome Institute at Shanghai University,with research focus on the microstructure and interface in thermoelectric materials and multiferroic ceramics,using Cs-corrected/in-situ transmission electron microscopy techniques;Corresponding author:Prof.Hui Gu is a professor in the School of Materials Science and Engineering&Materials Genome Institute at Shanghai University.He received Ph.D.from Department of Physics at Peking University in 1989.He was a Postdoctoral fellow in the Institute of Physics at Chinese Academy of Science in 1989 and 1990.He had worked as a postdoc in the Laboratory of Solid State Physics at the French National Centre for Scientific Research from 1991 to 1993.Prof.Gu had his postdoctoral research at Max-Planck Institut für Metallforschung,Stuttgart,Germany from 1993 to 1995.From 1996 to 1999,he was a researcher for Japan Science and Technology Agency.His research focuses on multiscale regulation of microstructures and their microstructure-property relationships.,gujiaoshou@shu.edu.cn。
