摘要
In this work, different amount of Cr_(2)O_(3) (x - 0e0.3 wt%) as dopant were doped into the Aurivillius-typecompound Bi2.8Gd0.2TiNbO9 (BGTN), such a kind of Gd/Cr co-doped Bi3TiNbO9 ceramics with improvedelectrical properties were synthesized by the convenient solid-state reaction route. The substitution of Cr^(3+) for Ti^(4+) at B-site induced the lattice distortion of pseduo-perovskite layer. Fewer Cr_(2)O_(3) dopant(x<0.2) resulted in the grain refinement of ceramics. After Cr_(2)O_(3) was added into BGTN, TC decreased tothe vicinity of 908 ℃. Below TC, the relaxed dielectric response resulted from charge carriers hoppinginduced another board dielectric permittivity peak, whose starting temperature shifts toward lower sidegradually with increase of x. The values of Eacon calculated from the Arrhenius relationship betweenconductivity and temperature indicated the intrinsic conduction at high temperature is dominated by thelong-range migration of doubly ionized oxygen vacancies. Moderate Cr_(2)O_(3) dopant (x=0.1e0.25) areconducive to the enhancement of piezoelectric property and thermal stability. The sample with x=0.2 achieved both a high T_(C)~903 - C and a high d_(33)~18 pC/N at the same time. Also, its d33 can retain 80% ofthe initial value after the sample was annealed at 800 - C for 4 h.
基金
This work was supported by the National Natural ScienceFoundation of China (Grant No. 11702037, 51932010)
China Post-doctoral Science Foundation Funded Project (Grant No.2017M623025)
Opening foundation from the Key Laboratory ofDeep Earth Science and Engineering (Sichuan University), Ministryof Education (Grant No. 202007).
作者简介
Corresponding author:Dr. Yu Chen: Yu Chen received his Bachelor's degree(2006) and Master's degree (2009) in the major of mate-rials science from Sichuan University, and got his Ph. D.degree (2016) in the major of solid mechanics fromSichuan University (studied at the University of Liverpool,UK between Jan. 2015 and Jan. 2016). Now, he is anassociate professor in the department of materials engi-neering at Chengdu University. His main research interestsfocus on piezoelectric/ferroelectric materials and theirapplications in the smart sensing and energy harvestingdevices. So far, he has published more than 40 papers inthe journals, including Acta Mater., Mater. Des., Scr. Mater.,J. Adv. Ceram., J. Am. Ceram. Soc. et al. Now, he acts as theassistant editor for the Journal of Advanced Ceramics andthe guest editor for the journal of Materials.University School of Mechanical Engineering,Chengdu,610106,China.E-mail addresses:chenyu01@cdu.edu.cn;Corresponding author.Prof. Jianguo Zhu: Jianguo Zhu received his MS degree in1987 and Ph. D degree in 1988 in th major of Solid Physicsfrom Sichuan University. From 1987 to 1988, he worked atthe Department of Physics, Sichuan University as an as-sistant professor. Since 1988, he worked at the Depart-ment of Materials Science in Sichuan University as anassistant professor, associate professor and professor,successively. His research interests mainly focus on thecontrollable synthesis, microstructural characterizationand property optimization of ferroelectric, piezoelectricand dielectric materials. Zhu is the author of over 300 SCIpapers, 9 books and over 20 Chinese patents and pre-sented about 50 invited lectures in various meetings andconferences.E-mail addresses:nic0400@scu.edu.cn。
