共查询到16条相似文献,搜索用时 46 毫秒
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采用固相烧结工艺制备了(SrBi2Nb2O9)χ(Na0.5Bi25Nb2O/9)1-χ(SBN-NBN,χ=0.1,0.3,0.6,0.9)新型铋层状结构无铅压电陶瓷.用X射线衍射仪、扫描电镜、介电和铁电测试系统分析SBN-NBN的结构、微观形貌与性能.结果表明:随着SBN含量的增加,样品均形成了稳定的层状铋结构,Curie温度(θc)减小,铁电-顺电相变弥散减弱,当χ≤0.6时,剩余极化强度(2Pr)和矫顽场(Ec)均增大,当χ0.6时,2Pr和Ec均减小.当χ=0.6时,θc650℃,2Pr=18.93μC/cm2,Ec=86.79kV/cm,均大于两单体系的.进一步研究了SBN和NBN两个预合成粉料的共混工艺对其性能的影响.结果表明:共混工序的差异对烧结体的物相结构没有产生明显影响,但对铁电性能产生了不容忽视的影响,两预合成粉造粒前混合比造粒后混合制得样品的θc高,弥散特性弱且易于极化. 相似文献
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采用固相法制备Na0.5Bi4.5Ti4O15+x%Co2O3+y%MnCO3(NBT-CM-x)(y=0.1x)铋层状无铅压电陶瓷,研究了Co、Mn共掺杂对Na0.5Bi4.5Ti4O15陶瓷显微结构和电性能的影响。结果表明:所有样品均为铋层状结构;Co、Mn共掺杂能促进陶瓷晶粒生长;随Co、Mn共掺杂量的增加,Curie温度TC逐渐升高(均在635℃以上);Cole-Cole图出现2个圆弧,表明存在晶粒和晶界效应;适量Co、Mn共掺杂提高了Na0.5Bi4.5Ti4O15陶瓷的压电常数d33、剩余极化强度Pr、机械品质因数Qm和相对介电常数εr,降低了直流电导率σDC和介电损耗tanδ。当x=3.0时,NBT-CM-x陶瓷的综合性能最佳:d33=24pC/N,Pr=11.70μC/cm2,Qm=3 117,εr=198,tanδ=0.19%,kp=9.9%,kt=14.7%,表明该陶瓷材料具有良好的高温应用前景。 相似文献
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综合介绍了Na0.5Bi0.5TiO3(sodium bismuth titanate,NBT)基无铅铁电材料在铁电相变和弛豫特性方面近年来国内外的研究进展。介绍了温度变化对NBT铁电性能的影响以及产生弛豫相变的机理。此外,结合本课题的研究成果,介绍了不同含量BaTiO3和K0.5Bi0.5TiO3及其它化合物取代后对NBT基铁电相变和弛豫特性的影响。指出了在提高压电性能的同时,大幅降低材料铁电一反铁电相变,即材料的退极化温度,可能会影响到压电陶瓷材料的使用温度范围。 相似文献
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改善锆钛酸铅(PZT)压电陶瓷灵敏度并增强其在静水压下的稳定性具有重要的实际意义。本文采用传统固相反应法,制备了xPb(Sb1/2Nb1/2)O3-(1-x)Pb(Zr0.52Ti0.48)(PSN-PZT,x=0.018,0.020,0.022, 0.025,0.030)压电陶瓷,研究了PSN对PZT压电陶瓷物相、显微形貌、居里温度、介电性能、铁电性能及压电性能的影响,对比测试了PSN-PZT及传统高灵敏度压电陶瓷在5~30 MPa的灵敏度。结果表明,PSN的引入能明显改善PZT压电陶瓷灵敏度,提升其静水压优值(HFOM)。当x=0.020时,PSN-PZT陶瓷拥有最佳的电学性能,此时平面机电耦合系数kp=0.641、纵向压电应变常数d33=325 pC/N、横向压电电压常数g31=16.642 mV·m·N-1、等静压压电电压常数gh(5 MPa)=9.91 mV·m-1·Pa-1、HFOM (5 MPa)=679×10-15 Pa-1。 相似文献
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Juan-Nan Chen Qian Wang Xian Zhao Chun-Ming Wang 《Journal of the American Ceramic Society》2022,105(7):4815-4826
Bismuth layer–structured ferroelectric calcium bismuth niobate (CaBi2Nb2O9, CBN) is considered to be one of the most potential high-temperature piezoelectric materials due to its high Curie temperature Tc of ∼940°C, but the drawbacks of low electrical resistivity at elevated temperature and low piezoelectric performance limit its applications as key electronic components at high temperature (HT). Herein, we report significantly enhanced dc electrical resistivity and piezoelectric properties of CBN ceramics through rare-earth element Tb ions compositional adjustment. The nominal compositions of Ca1−xTbxBi2Nb2O9 (abbreviated as CBN-100xTb) have been fabricated by conventional solid-state reaction method. The composition of CBN-3Tb exhibits a significantly enhanced dc electrical resistivity of 1.97 × 106 Ω cm at 600°C, which is larger by two orders of magnitude compared with unmodified CBN. The donor substitutions of Tb3+ ions for Ca2+ ions reduce the oxygen vacancy concentrations and increase the band-gap energy, which is responsible for the enhancement of dc electric resistivity. The temperature-dependent dc conduction properties reveal that the conduction is dominated by the thermally activated oxygen vacancies in the low-temperature region (200–350°C) and by the intrinsic conduction in the HT region (350–650°C). The CBN-3Tb also exhibits enhanced piezoelectric properties with a high piezoelectric coefficient d33 of ∼13.2 pC/N and a high Tc of ∼966°C. Moreover, the CBN-3Tb exhibits good thermal stabilities of piezoelectric properties, remaining 97% of its room temperature value after annealing at 900°C. These properties demonstrate the great potentials of Tb-modified CBN for high-temperature piezoelectric applications. 相似文献