BNT基无铅压电陶瓷的制备及性能研究

发布时间：2018-04-03 10:01

  本文选题：BNT基　切入点：无铅压电陶瓷　出处：《聊城大学》2014年硕士论文

【摘要】：Bi0.5Na0.5TiO3（BNT）基无铅压电陶瓷因优异的铁电性能和较高的居里温度而成为无铅压电材料领域的研究热点。为了进一步改善BNT基无铅压电陶瓷的性能，本文从离子掺杂、多组元改性和添加烧结助剂这三个方面对BNT基无铅压电陶瓷进行了改性研究。本课题采用的制备方法为传统固相合成法，研究的主要内容及结论如下： 1.研究了Sm3+、Co3+和Bi3+、Cr3+两对离子复合掺杂以及Al3+B位掺杂对BNT基陶瓷微观结构和电学性能的影响。研究表明：所有实验样品均具有纯的钙钛矿结构；Sm3+、Co3+复合掺杂能够明显促进0.94Bi0.5Na0.5TiO3-0.06BaTiO3（BNBT6）陶瓷晶粒的生长，提高陶瓷压电常数d33、机电耦合系数kp的同时,提高陶瓷的机械品质因数Qm，掺杂量为0.4mol%的陶瓷样品综合性能最佳：d33=144pC/N, kp=29.1%, Qm=219。Bi3+、Cr3+的复合掺杂使0.93Bi0.5Na0.5TiO3-0.07BaTiO3（BNBT7）晶格发生畸变，晶胞参数c/a随掺杂量的增大呈增大的趋势；Bi3+、Cr3+的复合掺杂能够明显改善陶瓷的电性能，当掺杂量为0.6mol%时，陶瓷样品的综合性能最佳：剩余极化强度Pr高达41.7μC/cm2，矫顽场强度Ec降至17.6kV/cm，d33高达205pC/N，kp为19.3%。Al3+的掺入使Bi0.5Na0.36K0.09Li0.05TiO3（BNKLT）陶瓷的压电常数d33和机电耦合系数kp略有降低，适量的Al3+掺杂可以提高陶瓷的机械品质因数Qm。 2.引入(Ba0.90Ca0.10)(Ti0.92Sn0.08)O3和LiSbO3组元，制备了(1-x)Bi0.5Na0.5TiO3-x(Ba0.90Ca0.10)(Ti0.92Sn0.08)O3[(1-x)BNT-xBCST]和(0.94-x)Bi0.5Na0.5TiO3-0.06BaTiO3-xLiSbO3[(0.94-x)BNT-0.06BT-xLS]陶瓷体系，研究表明：(1-x)BNT-xBCST陶瓷体系在所研究的范围内（x=0.0~0.14）均具有纯的钙钛矿结构，当0.07≤x≤0.14时，存在三方相和四方相共存。Ba0.90Ca0.10Ti0.92Sn0.08O3组元的引入使陶瓷的铁电性能和压电性能得到了明显的改善，当x=0.08时，陶瓷的压电常数d33高达219pC/N,机电耦合系数kp为20%，矫顽场强度Ec为21.3kV/cm。适量LiSbO3组元的引入明显的促进了(0.94-x)BNT-0.06BT-xLS陶瓷晶粒的生长，适量LiSbO3组元加入能够改善陶瓷的压电性能，当x=0.015时，压电常数d33=149pC/N，机电耦合系数kp=0.23，机械品质因数Qm=143。 3.制备了（1-x）BNT-xSrFeCo0.5Oy压电陶瓷，SrFeCo0.5Oy作为烧结助剂能够明显促进BNT陶瓷晶粒的生长，降低陶瓷的烧结温度，，能够将BNT陶瓷的烧结温度降至1050oC。另外，SrFeCo0.5Oy能够改善BNT压电陶瓷的铁电、压电性能，具有复合掺杂改性的作用，当x=0.06时，陶瓷样品的综合性能最佳：d33=92pC/N，kp=0.15，Qm=383。
[Abstract]:Bi0.5Na0.5TiO3BNT-based lead-free piezoelectric ceramics have become a hotspot in the field of lead-free piezoelectric materials due to their excellent ferroelectric properties and high Curie temperature.In order to further improve the properties of BNT based lead-free piezoelectric ceramics, the modification of BNT based lead-free piezoelectric ceramics was studied from the aspects of ion doping, multicomponent modification and sintering additives.The main contents and conclusions of this study are as follows:1.The effects of Sm3 Co _ 3 and Bi3 _ Cr _ 3 ion compound doping and Al3 B site doping on the microstructure and electrical properties of BNT based ceramics were investigated.The results show that all the samples have pure perovskite structure and Sm ~ 3 / Co _ 3 complex doping can obviously promote the growth of 0.94Bi0.5Na0.5TiO3-0.06BaTiO3-0.06BaTiO3BNBT6) ceramics, increase the piezoelectric constant d33and the electromechanical coupling coefficient (kp).By improving the mechanical quality factor (Qm) of the ceramics, the ceramic samples doped with 0.4 mol% have the best comprehensive properties: D33144pC / N, KpT29.1 and the composite doping of Qm=219.Bi3 / Cr3 distorts the lattice of 0.93Bi0.5Na0.5TiO3-0.07BaTiO3BNBT7.The crystal cell parameter c / a increases with the increase of doping amount. The composite doping of Bi _ 3O _ (3) Cr _ (3) can obviously improve the electrical properties of the ceramics. When the doping amount is 0.6 mol%,闄剁摲鏍峰搧鐨勭患鍚堟

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