锰锑酸铅-锌铌酸铅-锆钛酸铅陶瓷的压电性能

以同时位于准同型相界的Pb(Mn1/3Sb2/3)0.05(Zr1/2Ti1/2)0.95O3(PMnS-PZT)与Pb(Zn1/3Nb2/3)0.28(Zr1/2Ti1/2)0.72O3(PZN-PZT)组合而成的xPb(Mn1/3Sb2/3)0.05(Zr1/2Ti1/2)0.95O3-(1-x)Pb(Zn1/3Nb2/3)0.28(Zr1/2Ti1/2)0.72O3[xPMnS-(1-x)PZN]四元系压电陶瓷为研究对象,研究了PZN和PMnS含量的变化对xPMnS-(1-x)PZN材料结构与性能的影响,制备了具有高性能的四元系xPMnS-(1-x)PZN陶瓷材料.结果表明:性能最好的组成位于准同型相界附近靠近四方相含量较高的区域.Ba2 ,Sr2 取代显著提高了材料的压电性能,Ba2 取代0.5PMnS-0.5PZN的性能为压电系数da3=406 pC/N,机电耦合系数kp=0.55,介电常数εT33/ε0=2 183,机械品质因数Qm=1 077和介电损耗tan δ=2.7%;Sr2 取代0.6 PMnS-0.4 PZN的性能为d33=438 pC/N,kp=0.55,εT33/ε0=2 701,Qm=1 073和tan δ=3.3%.     

PMnS-PZN-PZT压电纤维的制备与铁电性能

采用固相法制备了0.8Pb(Mn1/3Sb2/3)0.05(Zr1/2Ti1/2)0.95O3–0.2Pb(Zn1/3Nb2/3)0.28(Zr1/2Ti1/2)0.72O3(PMnS–PZN–PZT)粉末,然后用塑性聚合物方法制备了PMnS–PZN–PZT压电纤维。研究了纤维夹持状态对其铁电性能的影响。结果表明:塑性聚合物法制备的PMnS–PZN–PZT压电纤维具有良好的铁电性能,压电纤维处于自由状态时,剩余极化强度和矫顽场分别为85.4μC/cm2和8.5kV/cm,但电滞回线很难饱和。将纤维采用环氧树脂固化后,剩余极化强度变成39.2μC/cm2,电滞回线呈饱和状态,说明夹持状态对纤维的铁电性能产生很大的影响。高压下压电纤维浇铸前后的漏电流测试结果表明,压电纤维浇铸后剩余极化强度变小主要与漏电流有关。     

铌镁酸钡缓冲层对锆钛酸铅薄膜漏电流的抑制

将铌镁酸钡(Ba(Mg1/3Nb2/3)O3,BMN)作为缓冲层,通过溶胶-凝胶法制备了锆钛酸铅(Pb(Zr0.52Ti0.48)O3,PZT)铁电薄膜.探究BMN缓冲层对PZT铁电薄膜介电、铁电性能影响.研究发现:BMN缓冲层不仅可以改善PZT薄膜晶化生长,同时阻碍了PZT与Pt的互扩散而降低了漏电流.由于对漏电流的抑制作用,适当厚度BMN缓冲层的引入可改善PZT的铁电性能,但随着缓冲层厚度的增加,由于其分压作用,复合膜铁电性减弱.当厚度为10 nm时,薄膜的综合性能最好:介电常数εr=1612.03,介电损耗tanδ=0.024,剩余极化值Pr=31.65 μC/cm2,矫顽场Ec=71.5 kV/cm,漏电流密度J=4.4×10-6 A/cm2.     

掺BaTiO3对（1-x）NBT—xBaTiO3系陶瓷材料的铁电牲能的影响

采用RadiantPrecisionWorkstation铁电测试系统测试样品的铁电性能，分析BaTiO3的掺人对（1-x）NBT—xBaTiO3系陶瓷材料的铁电性能的影响。实验结果表明：Ba2＋的掺入可有效地降低NBT基陶瓷的剩余极化强度和矫顽场，在准同型相界组成点，矫顽场达到最小值。     

PBSZT系大功率压电陶瓷极化工艺的研究

为探索大功率低损耗压电陶瓷材料的最佳制备工艺,对改性锆钛酸铅压电陶瓷Pb0.9Ba0.05Sr0.05(Sn1/3Nb2/3)0.06(Zn1/3Nb2/3)0.06Ti0.44Zr0.44O3 0.5wt%MnO2 0.5wt%Sb2O3的极化工艺进行研究。结果表明,该体系的最佳极化电场为4Kv/mm,极化温度120℃左右,此时得到的陶瓷性能较佳。     

锆钛酸铅镧压电陶瓷纤维的制备与性能

以锆钛酸铅镧[(Pb1-xLax)(Zr1-yTiy)O3,lead lanthanum zirconate titanate,PLZT]压电陶瓷为原料,用塑性聚合物法制备不同截面的PLZT陶瓷纤维。用X射线衍射、扫描电镜、密度测试仪、微力试验机和铁电分析仪分别测试PLZT陶瓷纤维的相结构、显微形貌、密度、力学性能和铁电性能。结果表明:PLZT陶瓷纤维为三方相钙钛矿结构,圆柱形纤维的直径和方柱形纤维的边长分别约250μm和300μm。圆柱形和方柱形纤维的最终抗拉伸强度和弹性模量分别为24.88MPa、6.90×103MPa和23.97MPa、5.71×103MPa。PLZT陶瓷纤维均具有良好的铁电性能,圆柱形纤维的饱和场强、剩余极化强度(Pr)和矫顽场(Ec)分别为10kV/mm、41.40μC/cm2和1.10kV/mm;方柱形的饱和场强、Pr及Ec分别为10kV/mm、41.68μC/cm2和1.03kV/mm。     

射频磁控溅射制备PZT铁电薄膜的工艺研究

在SiO2/Si基片上采用直流对靶溅射技术制备出Pt/Ti底电极;应用射频磁控溅射方法,利用快速热处理(RTA)工艺,制备出了具有良好铁电性能的Pb(Zr0.52Ti0.48)O3铁电薄膜.将样品进行10min快速热退火处理,退火温度700℃.测试分析表明:薄膜厚度比较均匀、表面基本平整、没有裂纹和孔洞、致密性好、薄膜样品的矫顽场强(Ec)为28.6kV/cm,剩余极化强度(Pr)为18.7μC/cm2,自发极化强度(Ps)为37.5μC/cm2,是制备铁电薄膜存储器的优选材料.     

xPb(Mg_(1/3)Nb_(2/3))O_3–(1–x)Pb(Zr_(0.48)Ti_(0.52))O_3压电陶瓷的准同型相界与介电性能

采用铌铁矿预产物合成法制备组成在准同型相界(morphotropic phase boundary,MPB)附近的xPb(Mg1/3Nb2/3)O3-(1-x)Pb(Zr0.48Ti0.52)O3(PMN-PZT,x=0.125,0.15,0.175,0.2,0.225,0.25,摩尔分数)压电陶瓷。X射线衍射和Raman光谱分析表明:所有陶瓷样品的相组成均为纯钙钛矿相,未探测到其他杂相;随PMN含量的增加,PMN-PZT压电陶瓷的相结构从四方相逐渐向菱方相转变,该体系的MPB组成在x=0.2附近,而且其相结构为四方相与菱方相共存。陶瓷断口的扫描电镜观察表明:陶瓷的晶粒尺寸约1～3μm。陶瓷的介电温谱表明:x=0.2,陶瓷的Curie温度为308.8℃,峰值介电常数约为16380,室温压电常数为351pC/N;陶瓷的Curie温度随PMN含量增加线性下降。     

钽镁酸钡缓冲层对锆钛酸铅铁电薄膜性能的影响

采用溶胶–凝胶工艺在Pt/Ti/Si O2/Si基片上,通过引入钽镁酸钡[Ba(Mg1/3Ta2/3)O3,BMT]缓冲层,制备了锆钛酸铅[Pb(Zr0.52Ti0.48)O3,PZT]铁电薄膜。研究了BMT缓冲层对PZT铁电薄膜结晶和性能的影响。结果表明:引入BMT缓冲层利于PZT薄膜的生长;PZT薄膜具有钙钛矿结构,且没有裂纹、结晶良好、致密性好;缓冲层的厚度对PZT铁电薄膜的微观结构和铁电性能有重要影响。随BMT缓冲层厚度增加,PZT晶粒增大,介电损耗tanδ逐渐减少,介电常数εr和剩余极化强度Pr先增大后减少,矫顽场Ec先减少后增大。当BMT缓冲层厚约为10 nm时,PZT薄膜具有最优的铁电性能:εr=1 850,Pr=20.2μC/cm2,Ec=43.9 k V/mm。这与BMT与PZT具有相似的晶格常数、较小的晶格失配度和相近的禁带宽度有关。     

碳酸锂掺杂对PFN-PNN-PZT陶瓷微结构和电学性能的影响

采用传统固相烧结法制备了(1-x)Pb[(Fe1/2Nb1/2)0.1(Ni1/3Nb2/3)0.45(Zr0.3Ti0.7)0.45]O3-xLi2CO3(PFN-PNN-PZTxLi,x=0、0.5%、1.0%、1.5%、2.0%)压电陶瓷,研究了不同Li2CO3含量(x)对陶瓷微观形貌、相结构、介电、压电和铁电性能的影响。X射线衍射和扫描电子显微镜分析表明:制备的陶瓷样品均为单一钙钛矿结构,未探测到其他杂相;随着Li2CO3含量的增加,陶瓷的晶体结构从三方相向四方相转变。电学性能测试表明:Li2CO3掺杂几乎不影响PFN-PNN-PZT陶瓷的特征Curie温度,但能显著提高介电温度系数γ;随着Li2CO3掺杂量的增加,陶瓷压电常数d33和机电耦合系数kp降低,而相应的机械品质因数Qm和矫顽场Ec增大,说明Li2CO3表现为"硬性"掺杂特点;当x=1.5%时,1 200℃烧结2h的陶瓷具有相对较好的电学性能:d33=820pC/N,kp=0.63,相对介电常数εr=6 628,tanδ=0.028,介电温度系数γ=17%,Qm=52.6,Ec=4.48kV/cm。     

Pb(Zr,Sn,Ti)O3中组份变化对反铁电-铁电相变的影响

探讨了掺铌Ｐｂ（Ｚｒ,Ｓｎ,Ｔｉ）Ｏ３反铁电陶瓷中,组份变化对晶体结构及电场诱导反铁电－铁电相变性能的影响,分析结果表明;在Ｐｂ０．９９Ｎｂ０．０２〖（Ｚｒ１－ｘＳｎｘ）１－７Ｔｉｙ〗０．９８Ｏ３反铁电陶瓷中,ｙ增加,反铁电四方相晶轴比减小,增加晶胞体积,诱导反铁电－铁电相变的开关电场强度降低,ｘ增加,反铁电四放相的晶轴比ａ／ｃ铁电相变的反铁电相区。     

Ba(Zr_(0.055)Ti_(0.945))O_3含量对[(Na_(0.80)K_(0.16)Li_(0.04))_(0.5)Bi_(0.5)]TiO_3陶瓷性能的影响

系统研究(1-y)[(Na0.80K0.16Li0.04)0.5Bi0.5]TiO3-yBa(Zr0.055Ti0.945)O3无铅压电陶瓷,获得压电应变常数高达185pC/N的0.94[(Na0.80K0.16Li0.04)0.5Bi0.5]-TiO3-0.06Ba(Zr0.055Ti0.945)O3压电陶瓷。样品的晶体结构为三方相、四方相共存,处于准同型相界(morphotropic phase boundary,MPB)附近。该类陶瓷室温MPB的摩尔(下同)含量为0.050y0.065。样品y=0.060在40°左右的(003)、(021)双峰与46.5°左右的(002)、(200)双峰分裂最明显。随着Ba(Zr0.055Ti0.945)O3含量的增加,铁电相-反铁电相相变温度(θd)升高、反铁电相-顺电相相变温度(θm)降低;θd和θm的温差越来越小,材料的弛豫性逐渐降低。     

Li2CO3掺杂对0.2PMN-0.8PZT陶瓷的影响

利用铌铁矿预产物合成法,研究不同温度烧结下Li2CO3掺杂对0.2 PMN-0.8PZT压电陶瓷(简称PLC)的相结构和电性能的影响。X射线衍射(XRD)和扫描电镜(SEM)的分析结果表明,掺杂LiCO3的0.2PMN-0.8PZT压电陶瓷经不同温度煅烧后,所有陶瓷样品的相组成均为纯钙钛矿相,并随着烧结温度的升高,PLC的相结构有由四方相向菱方相转变的趋势。通过0.2PMN-0.8PZT压电陶瓷掺杂LiCO3煅烧后的微观形貌、介电常数、压电性能、铁电性能的分析,发现经1200℃烧结的样品的介电和压电性能最佳:介电常数(εr)为38512,室温压电常数(d33)为300 pC/N,剩余极化强度(Pr)为31.3 C/cm2,矫顽电场(Ec)为7.5 kV/cm。     

Ba3 Ti5+xNb6-x O28-x/2陶瓷微波介电性能

＝28419 GHz、τf＝-12 ppm/℃(x=0.1).     

Bi_2O_3掺杂对PBSZT压电-铁电陶瓷结构和特性的影响

采用扎膜工艺和固相反应法制备了Bi2O3掺杂的(Pb0.70Ba0.26Sr0.04)(Zr0.52Ti0.48)O3–xBi2O3(Bi–PBSZT,x=0,0.1%(质量分数,下同),0.3%,0.5%,0.8%,1.0%)压电–铁电陶瓷。通过扫描电镜和X射线衍射表征Bi–PBSZT陶瓷的结构和物相组成,并对其弯曲强度(σb)、相对介电常数(εr)和横向压电应变常数(d31)进行了检测和分析。结果表明:适量Bi2O3(x=0～0.3%)掺杂可使Bi–PBSZT陶瓷晶粒细化,致密度提高,σb增大;陶瓷的εr和d31下降。当Bi2O3掺杂量为0.3%时,Bi–PBSZT陶瓷的性能得到优化,σb为175.21MPa,εr为5520,d31为518×10–12m/V。     

Effect of Zn and Ti Co-doping on structure and electrical properties of BiFeO3 ceramics

In this paper, the effect of Zn and Ti co-doping on the structure, dielectric, ferroelectric and magnetic properties of BiFeO₃ (BFO) ceramics have been studied. Co-doped BFO ceramics with different doping concentrations are prepared by using the sol-gel method. The structure, morphology and electrical properties of co-doped BFO ceramics are studied by using X-ray diffraction (XRD), scanning electron microscopy, impedance analyzer and ferroelectric test analysis system. Furthermore, the vibrating sample magnetometer (VSM) is used to investigate the magnetic properties. The structural transition from rhombohedral to tetragonal-like phase is observed with a high level of co-doping (x = 2.5%). In addition, higher content of Zn and Ti results in enhanced dielectric constant (ε) and reduced dielectric loss (tanδ). The highest remnant polarization of 0.4 μC/cm² and coercive electric field of 15.5?kV/cm is demonstrated at x = 2.5%. The enhanced dielectric and ferroelectric properties can be attributed to the formation of defect complexes due to the Zn and Ti substitution.     

Composition design,phase transitions and electrical properties of Sr2+-substituted xPZN–0.1PNN–(0.9−x)PZT piezoelectric ceramics

The influences of PZN content and Sr²⁺ substitution on the structure and electrical properties of Pb(Zn_1/3Nb_2/3)O₃–Pb(Ni_1/3Nb_2/3)O₃–Pb(Zr_0.52Ti_0.48)O₃ (abbreviated as PZN–PNN–PZT) piezoelectric ceramics were studied. All as-prepared PZN–PNN–PZT ceramics presented single phase of perovskite structure, while higher PZN contents favored rhombohedral symmetry and larger grain size. Meanwhile, with the increase in Sr²⁺ content, the phase structure changed from a mix of tetragonal and rhombohedral symmetries to a pure rhombohedral symmetry. Although the ferroelectric Curie temperature (T_C) was decreased with increasing the PZN and Sr²⁺ contents, the piezoelectric constant (d₃₃) exhibited the opposite trend. As a result, optimum comprehensive electrical properties were obtained in the 0.1PZN–0.1PNN–0.8PZT composition with 10 mol% Sr²⁺ substitution: d₃₃~800 pC/N, k_p ~0.65, ɛ_r~4081, T_C~176 °C, P_r~30.92 µC/cm². Thus, the 10 mol% Sr²⁺-substituted 0.1PZN–0.1PNN–0.8PZT ceramic is a promising candidate for high performance applications.     

Relationship Between Structure and Electric Properties of （0.99–x）BNT–xBKT–0.01KNN Near Morphotropic Phase Boundary

研究了三方、四方共存[即准同型相界（morphotropic phase boundary,MPB）]附近（0.99–x）Bi0.5Na0.5TiO3–xBi0.5K0.5TiO3–0.01K0.5Na0.5NbO3[（0.99–x）BNT–xBKT–0.01KNN,x=0.16～0.23]无铅压电陶瓷的电学性能与其结构之间的变化关系。X射线衍射分析表明,随着x的增大,陶瓷材料相结构由三方相转变为四方相。当x=0.20时,（111）和（200）面衍射峰均形成劈裂峰,标志着该组分的相结构由三方–四方相共同组成,形成MPB区。样品的介电温谱表明,铁电–反铁电转变温度（Td）随着x的增大而减小,但Curie点（TC）并未明显变化。电致应变（S）随着x的增大,呈现先增加后减小的趋势,并在x=0.20时得最大值0.46%,此时动态压电系数约为575 pm/V。电滞回线显示,陶瓷样品的剩余极化强度Pr和矫顽场Ec都随着x的增大而减小,分别由41.5μC/cm2降为15.2μC/cm2和由46.5kV/cm降为15.0kV/cm,并伴随着电滞回线由扁平到束腰的形状变化,呈现从铁电相特性到反铁电相特性的转变过程。     

Effect of Microstructure on Ferroelectric and Piezoelectric Properties of A-Site and B-Site Modified PLZT

Ba modified (Pb,La,Ag)(Zr,Ti)O₃ ceramics synthesized by conventional mixed-oxide method with chemical formula [Pb_{0.983 - z}La_0.012Ag_0.005Ba_z] [(Zr_0.52Ti_0.48)_0.99825]O₃ were investigated for ferroelectric and piezoelectric properties. XRD studies indicate that increment of Ba concentration resulted in strong tetragonality in the ceramics. Grain growth (3.08 μ m) inhibited and apparent density (7.54 gm/cm³) enhanced up to 1.5 mole% Ba respectively. As Ba content increased dielectric properties showed maximum values (ε_RT = 2347, ε_Tc = 23449) while T_c constantly decreased. The remanent (P_r = 34.72 μ C/cm²) and spontaneous polarization (P_s = 41.84 μ C/cm²) were optimum in 1 mole% Ba respectively while E_c showed increasing trend throughout the series. Piezoelectric properties attained maximum values of d₃₃ = 438 pC/N in 1.5 mole% Ba while k_p = 0.533 and k_t = 0.412 in 1 mole% Ba doped (Pb,La,Ag)(Zr,Ti)O₃ ceramics respectively.     

烧结温度对大功率超薄型压电蜂鸣器用压电陶瓷结构和性能的影响

采用轧膜成型工艺制备大功率超薄型峰鸣器用压电陶瓷。该陶瓷是三方／四方相共存PSN—PBZT(0．02Pb(Sb0．5Nb0．5)O3—0．98PbxBa1-z(Zr0.55Ti0.45)O3)压电陶瓷。研究了烧结温度对三方／四方相共存PSN—PBZTB陶瓷性能的影响，利用XRD和SEM研究了烧结温度对其结构的影响。结果表明，随着烧结温度的升高，材料的晶格常数轴率比Ct／at逐渐升高，ar有所降低，同时，材料的晶粒尺才增大，材料的介电常数和机电耦合系数增大。但是，烧结温度太高将手致其介电常数和机电耦合系数降低，这是由于出现玻璃相和游离氧化锆稀释铁电相所致。