Doping level effects in Gd/Cr co-doped Bi_(3)TiNbO_(9) Aurivillius-type ceramics with improved electrical properties  

作　　者：Yu Chen Huajiang Zhou Qingyuan Wang Jianguo Zhu 

机构地区：[1]School of Mechanical Engineering,Chengdu University,Chengdu,610106,China [2]College of Materials Science and Engineering,Sichuan University,Chengdu,610065,China [3]Key Laboratory of Deep Earth Science and Engineering(Sichuan University),Ministry of Education,Chengdu,610065,China

出　　处：《Journal of Materiomics》2022年第4期906-917,共12页无机材料学学报（英文）

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).

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.

关 键 词：Aurivillius ceramics Bi_(3)TiNbO_(9) Ionic conduction Dielectric relaxation Oxygen vacancy 

分 类 号：TQ174[化学工程—陶瓷工业]