高温无铅压电陶瓷BFMT-BT的微结构与电性能

单旭¹，周昌荣¹，杨华斌¹，周沁¹，成钧¹，陈国华¹，李伟洲²

(1. 桂林电子科技大学 材料科学与工程学院，广西 桂林，541004；2. 广西大学 材料科学与工程学院，广西 南宁，530004)

摘 要：采用传统陶瓷制备方法，制备一种高温钙钛矿结构0.71BiFe_1-x(Mg_1/2Ti_1/2)_xO₃-0.29BaTiO₃ (BFMTx-BT)无铅压电陶瓷。研究Bi(Mg_1/2Ti_1/2)O₃(BMT)改性对该体系陶瓷微结构、介电、铁电与压电性能的影响。结果表明：在所研究的组成范围内BMT不改变陶瓷的晶体结构，居里温度随BMT含量的增加先保持不变，但随BMT的进一步增加明显降低，频率依赖性与弥散相变特征随BMT含量的增加更加明显。矫顽场随BMT含量的增加而降低，剩余极化在BMT含量x≤0.06时变化不大。添加BMT提高了陶瓷的压电常数d₃₃，但使机电耦合系数降低。在BMT含量x=0.03时，BFMTx-BT具有优良的压电性能(d₃₃为155 pC/N)与高居里温度(t_c为420 ℃)。

关键词：压电陶瓷；钙钛矿结构；弛豫特性；高温

Microstructure and electrical properties of high-temperature BFMT-BT Pb-free ceramics

SHAN Xu¹, ZHOU Changrong¹, YANG Huabin¹, ZHOU Qin¹, CHENG Jun¹, CHEN Guohua¹, LI Weizhou²

(1. School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China;2. School of Materials Science and Engineering, Guangxi University, Nanning 530004, China)

Abstract:A high-temperature perovskite-type 0.71BiFe_1-x(Mg_1/2Ti_1/2)_xO₃-0.29BaTiO₃ (abbreviated as BFMTx-BT) lead-free piezoelectric ceramics was prepared by a conventional ceramic sintering technique. The effect of Bi (Mg_1/2Ti_1/2)O₃(BMT) addition on microstructure, piezoelectric, dielectric and ferroelectric properties was investigated. The addition of BMT has no remarkable effect on the crystal structure within the studied doping content; however, an obvious decrease in Curie temperature took place. The characteristics of relaxor and diffuse phase transition were more obvious with the increase of BMT content. The coercive field E_c decreased with the increase of the amount of BMT and the remanent polarization P_r almost kept same values when x≤0.06. The piezoelectric constant d₃₃ increased obviously and the electromechanical coupling factor k_p decreased with BMT addition. The excellent piezoelectric properties of d₃₃=155 pC/N and high Curie temperature of t_c=420 ℃were obtained at x=0.03.

Key words:piezoelectric ceramics; perovskite; relaxor characteristics; high-temperature