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1.
最近的理论工作预期,可能存在一种新的无铅压电陶瓷xAgNbO3-(1-x)BaTiO3,认为在含12%AgNbO3的组分处存在准同型相界(MPB),具有良好的性能,并有较高的居里点。但是尚未见到有关这方面的实验报道。通过传统的固相反应法合成xAgNbO3-(1-x)BaTiO3陶瓷,其中取x等于0.08到0.16。首先在950℃下预烧3h合成AgNbO3-BaTiO3,然后将粉末球磨、压片后,在1150℃下进一步烧结得到样品。通过X射线衍射技术(XRD),研究了xAgNbO3-(1-x)BaTiO3的相结构,并对这一体系的电学性质进行了测试。发现x=0.12附近存在着MPB,且介电常数达到1000左右,剩余极化强度达到3.5μC/cm^2,矫顽场反为800V/mm。xAgNbO3-(1-x)BaTiO3作为一种可供选择的无铅压电陶瓷值得进一步的研究和开发。 相似文献
2.
基于准同型相界(morphotropic phase boundary, MPB) 线性组合规律,研究Pb(Mg_(1/3)Nb_(2/3))O_3 -Pb(Zn_(1/3)Nb_(2/3))O_3-PbTiO_3 (PMN-PZN-PT)三元系的MPB区域,并探求电学性能优越的组分.实验选取(1-x) (0.67 PMN- 0.33 PT)-x(0.91 PZN-0.09 PT) 系列中x=0~0.85的8个实验点;为减少焦绿石相的生成,陶瓷试样用铌铁矿预产物法合成,最终在1120~1160 ℃烧成.X射线衍射分析表明该系列试样均为钙钛矿结构,且处于四方与菱方两相共存态,验证了两个子二元系MPB组分的连线均为该三元系的MPB区域.少量的PZN-PT取代PMN-PT可以提高该三元系的电学性能;在x=0.1的组分获得该系列的最优性能:极值介电常数ε_(m,1 kHz)=28 030,剩余极化强度Pr=32.5 μC/cm~2,压电系数d_(33)=545 pC/N. 相似文献
3.
对Zr与Ti的原子比约为52/48,掺杂了少量La、Mn和Nb的PLZT铁电陶瓷进行了不同温度下的原位Raman谱观测,对所获得的谱图进行温度分布修正,再利用阻尼-谐振-振荡器模型的光谱响应函数及Gauss分布函数对所得结果进行分峰拟合,得到了各Raman峰的波数和峰强随温度的变化规律.结果表明,准同型相界附近的PLZT铁电陶瓷在47-600℃升温过程中,于240和360℃分别发生两次相变,表明样品中可能存在混合相;通过比较未极化和极化样品的Raman谱峰的变化结果,分析了预极化处理对相变的影响. 相似文献
4.
通过传统的固相烧结法合成(1-x)(Bi0.5Na0.5)TiO3-x(Bi0.5K0.5)TiO3陶瓷(x选取范围0.135-0.24)。先在850℃合成原料粉体,然后在1100~1200℃下烧结得到陶瓷样品。分析检测该体系陶瓷的结构以及铁电、压电性能。x射线衍射分析结果表明,该二元系准同型相界(MPB)区域位于x=0.165~0.225附近。对这一体系铁电和压电性能进行测试,并对其在准同型相界附近的电学性能发生变化的机理作了讨论。(Bi0.5Na0.5)TiO3-(Bi0.5K0.5)TiO3是一种很有应用前景的无铅压电陶瓷材料,值得进一步的研究和探索。同时,本实验还对密封烧结工艺对无铅压电陶瓷性能的影响作了初步的研究。 相似文献
5.
介绍了采用传统陶瓷制备工艺,为获得晶粒细小、组织致密、性能良好的铌酸钾钠基无铅压电陶瓷,目前所采取的性能控制措施,即添加助烧剂、掺杂改性、添加第二组元、准同型相界的研究及调整n(Na)/n(K),来调整NKN陶瓷的性能。展望了NKN基无铅压电陶瓷的发展趋势。 相似文献
6.
研究(1-x)(Bi0.5Na0.5)TiO3-xBa(Ti0.95Zr0.05)O3(BNT-BZT)体系陶瓷的准同型相界,以及陶瓷材料的微观结构和性能之间的关系.BNT-BZT陶瓷体系在富BNT和Zr含量低的区域存在准同型相界,在相界附近可能得到性能优良的无铅压电陶瓷,相界点在x≈0.1这个区域内.将BNT陶瓷和BZT陶瓷固溶后能够得到d33大于150 pC/N,居里温度在240℃左右,介电常数在900左右的性能良好的无铅压电陶瓷. 相似文献
7.
PMN-PT弛豫铁电陶瓷的低温烧结与压电性能 总被引:3,自引:0,他引:3
以LiF为烧结助剂研究了PMN-PT 68/32弛豫铁电陶瓷的低温烧结和压电性能.结果表明LiF烧结助剂完全固溶到PMN-PT陶瓷中形成具有复合钙钛矿结构的固溶体,无任何第二相存在.添加2.5%LiF烧结助剂可以使PMN-PT压电陶瓷的烧结温度从1250℃降到1000℃,而且该试样具有致密均匀的显微结构,其体积密度为7.87g/cm3,达理论密度的95%,其平面机电耦合系数为71%,压电常数为500pC/N左右,最大应变量达0.25%左右. 相似文献
8.
通过铌铁矿预产物法制备出了Pb[(Mgq/3Nb2/3)0.536(Ni1/3Nb2/3)0.128Ti0.336]O3铁电陶瓷,并对其结构和电学性能进行了研究.结果表明,该三元体系组成处在准同型相界区域,1kHz时的介电常数极值达到45540,剩余极化强度为37uC/gm2,压电系数d33也达到780pC/N.烧结时有效地抑制PbO的挥发对于获得高性能的铅系铁电陶瓷有决定性的影响. 相似文献
9.
钛酸铋钠(Bi0.5Na0.5TiO3,简称 BNT)基无铅压电陶瓷因其环境友好型、良好的铁电压电性能等特点在航空航天、舰艇声纳、高速列车及电子产品等领域得到广泛应用。为了克服钛酸铋钠基无铅压电陶瓷高矫顽场并进一步提升其电学性能, 通过对 BNT 基无铅压电陶瓷进行掺杂改性构建三方相–四方相共存的准同型相界(MPB)。掺杂改性是改善 BNT 基无铅压电陶瓷性能的一种重要方法,针对 BNT 基无铅压电陶瓷掺杂改性进行系统总结十分必要。主要从 BNT 基无铅压电陶瓷多组元改性、A / B 位离子掺杂和稀土离子掺杂改性等三方面综合论述近年来 BNT 基压电陶瓷研究进展。结果表明,引入合适的组元有利于 BNT 基无铅压电陶瓷构建三方相–四方相共存的准同型相界;A / B 离子掺杂是根据离子半径和电价大小的一致性对 BNT 陶瓷中对应位置的离子进行取代;稀土离子掺杂主要对该陶瓷的光电特性有显著影响。上述三方面从不同角度改善了 BNT 基无铅压电陶瓷的性能,以期为研究性能更好的 BNT 基无铅压电陶瓷的科研和技术人员提供参考,并为 BNT 基无铅压电陶瓷的实际应用奠定基础。 相似文献
10.
选取PMN-PNN-PZT四元系压电陶瓷准同型相界附近配方,采用传统的氧化物混合合成工艺制备压电陶瓷材料.研究了不同烧结温度对该四元系压电陶瓷微观结构和压电性能的影响,研究结果表明在1180℃烧结时,晶粒生长很好,晶界处结合致密,压电性能也最好d33=475pC/N,ε33T/ε0=3203, Qm=82,Kp=0.59,tanδ=1.8%. 相似文献
11.
Effects of CeO2 doping on the structure and properties of PSN-PZN-PMS-PZT piezoelectric ceramics 总被引:1,自引:0,他引:1
SUN Qingchi LU Cuimin ZHOU Hua 《稀有金属(英文版)》2005,24(3):235-239
Quinary system piezoelectric ceramics PSN-PZN-PMS-PZT were prepared by using a two-step method. The effects of CeO2 doping on piezoelectric and dielectric properties of the system were investigated at morphotropic phase boundary (MPB). The results reveal that the relative dielectric constant ε33^T|ε0, the Curie temperature To, the piezoelectric constant d33, the mechanical quality factor Qm, and the electromechanical coupling coefficient Kp are changed with the increase of CeO2 content. On the other hand, the effects of CeO2 doping on the dielectric properties of PSN-PZN-PMS-PZT piezoelectric ceramics at high electric field are consistent with the change at weak electric field. The values of dielectric constant and dielectric loss are enhanced with the increasing of electric field. 相似文献
12.
13.
Effect of sintering temperature and composition on microstructure and properties of PMS-PZT ceramics
The piezoelectric ceramics xPb(Mn1/3Sb2/3)O3-(1-x)Pb(Zr1/2Ti1/2)O3 (abbreviated as PMS-PZT) were synthesized by traditional ceramics process. The effect of sintering temperature and the amount of Pb(Mn1/3Sb2/3)O3 (abbreviated as PMS) on phase structure, microstructure, piezoelectric and dielectric properties of PMS-PZT ceramics was investigated. The results show that the pure perovskite phase is in all ceramics specimens, the phase structure of PMS-PZT ceramics changes from tetragonal phase to single rhombohedral phase with the increasing amount of PMS. The dielectric constant εr, Curie temperature Tc, electromechanical coupling factor kp and piezoelectric constant d33 decrease, whereas the mechanical quality factor Qm and dielectric loss tanδ increase with the increasing amount of PMS in system. The optimum sintering temperature is 1 200-1 250 ℃. It is concluded that the PMS-PZT (x=0.07) ceramics sintered at 1 250 ℃ is suitable for high-power piezoelectric transformer. These properties include εr=674.8, tanδ =0.005 25, kp=0.658, Qm= 1 520, d33=230 pC/N, Tc=275 ℃. 相似文献
14.
0.144(K0.5Bi0.5)TiO3-0.85(Na0.5Bi0.5)TiO3-0.006BaTiO3(KBT-NBT-BT) lead-free piezoelectric ceramics were prepared using a conventional solid state method.The influence of Sb2O3 doping on the crystal phase,surface microstructure and properties of the KBT-NBT-BT lead-free piezoelectric ceramics were investigated using X-ray diffraction(XRD),scanning electron microscope(SEM) and other analytical methods.The results show that all compositions are of pure perovskite structure solid states.Sb2O3 doping does not influence the microstructure of KBT-NBT-BT lead-free piezoelectric ceramics obviously in the Sb2O3 doping range of 0.1-0.5 wt.%.Sb2O3 functions as a donor when doped small amount,while functions as a acceptor when doped large amount.The piezoelectric strain constant(d33) increases first and then decreases;the dielectric constant(ε3T3/ε0) and the dielectric loss(tanδ) decrease continuously when the amount of Sb2O3 dopant increases.When the doping amount of Sb2O3 is 0.1 wt.%,the KBT-NBT-BT piezoelectric ceramics with good comprehensive properties are obtained,whose d33,ε3T3/ε0 and tanδ are 147 pC/N,1510 and 4.2%,respectively. 相似文献
15.
The coexistence of tetragonal and rhombohedral phases as elastic domains is studied in this paper for lead zirconate titanate (PZT) ferroelectric films near the morphotropic phase boundary (MPB). The volume fractions of the phases and different twin components are obtained as functions of misfit strain and film orientation. It is shown that the superior electromechanical properties of MPB-PZT films may be understood on the basis of a field-induced evolution of the heterophase polydomain structure. 相似文献
16.
The ceramics with Pb1.04Zr0.52Ti0.48O3 + z wt.% Cr2O3 were prepared using the traditional technique.The effects of Cr2O3 doping on the phase structure,the microstructure,and the electrical properties of ceramics were investigated.Meanwhile,the temperature stabilities of the resonant frequency (fr) were studied.The results showed that the △fr/fr,25℃ decreased with the addition of 0.2 wt.% - 0.8 wt.% Cr2O3 as compared with the undoped samples.The minimum value (-0.182%) of △fr/fr,25℃ was obtained for z = 0.6 wt.% Cr2O3 samples that sintered at 1260℃.The values of εT33/ε0 = 1650,tanδ = 0.006,d33 = 328 pC/N,Kp= 0.63,Qm = 2300 were obtained when Cr2O3 was 0.6 wt.%,which exhibited more excellent piezoelectric properties than other compositions such as those with z = 0.2 wt.%,0.4 wt.%,and 0.8 wt.%,but had a similar value as compared with the undoped samples.When the Cr2O3 additive increased,the Curie temperature moved toward low temperature and the changes of resonant frequency changed from positive to negative with increasing temperature. 相似文献
17.
The microstructures and dielectric properties of Sb2O3-doped Ti deficient barium strontium titanate ceramics prepared by solid state method were investigated with non-stoichiometric level and Sb2O3 content by SEM, XRD and LCR measure system. It is found that with the increase of δ, (Ba0.75Sr0.25)Ti1–δO3–2δ ceramics transform from single phase solid solutions with typical cubic perovskite structure to multiphase compounds while (Ba0.75Sr0.25)Ti0.998O2.996 ceramics remain to be single-phase with the increasing Sb2O3 content. The distortion of the ABO3 perovskite lattice caused by VTi″″ and Vo?? induces the drop of Curie temperature and the rise of relative dielectric constant in (Ba0.75Sr0.25)Ti1–δO3–2δ ceramics with increasing δ value. The orientation of Vo?? elastic dipoles results in the domain-wall pinning and thus the reduction of the dielectric loss. With increasing Sb2O3 content, the relative dielectric constant, dielectric constant maximum and Curie temperature of (Ba0.75Sr0.25)Ti0.998O2.996 ceramics decrease dramatically while the dielectric loss increases. 相似文献
18.
铋基无铅压电陶瓷Bi0.5(Na0.82K0.18)0.5TiO3-BiCrO3的微观组织与电性能 总被引:2,自引:0,他引:2
采用传统陶瓷制备方法,制备一种新型无铅压电陶瓷 (1-x)Bi0.5(Na0.82K0.18)0.5TiO3-xBiCrO3 (BNKT-BCx).研究Bi基铁电体BiCrO3对BNKT-BCx陶瓷晶体结构和压电介电性能的影响.结果表明:在所研究的组成范围内,陶瓷材料的主体结构为纯钙钛矿固溶体,微量BiCrO3(x=0~0.02,摩尔分数)不改变陶瓷的晶体结构;当BiCrO3含量x>0.02时,晶体结构由三方、四方共存转变为伪立方结构,并出现明显的第二相;当x=0.015时,d33=168 pC/N;当x=0.01时,kp=0.32,为该体系压电性能的最大值;随BiCrO3含量的增加,陶瓷的低温介电反常峰向低温移动,高温介电反常峰向高温移动,反铁电相区域增加,弥散指数增加. 相似文献
19.
Lead-free piezoelectric ceramics Lix(K0.46Na0.54)1-xNb0.86Ta0.1Sb0.0403 (with x ranging from 0 to 0.1) were synthesized by conventional solid state sintering method. The effect of cationic substitution of Li for K and Na in the A sites of perovskite lattice on the structure, phase transition behavior and electrical properties were investigated. Morphotropic phase boundaries(MPB) between orthorhombic and tetragonal phase are found in the composition range of 0.06≤x≤0.08. Analogous to Pb(Zr, Ti)O3, the dielectric and piezoelectric properties are enhanced for the composition near the morphotropic phase boundary. The Li0.06(K0.46Na0.54)0.94- Nb0.86Ta0.1Sb0.04O3 ceramics show excellent electrical properties, that is, piezoelectric constant d33=215 pC/N, planar electromechanical coupling factor kp=41%, dielectric constant ε33^T /ε0=1 303, and dielectric loss tan δ=2.45%. The results indicate that Lix(K0.46Na0.54)1 -xNb0.86Ta0.1Sb0.0403 ceramic is a promising lead-free piezoelectric material. 相似文献