CeO2掺杂制备Ba0.9Ca0.1Ti1-xSnxO3压电陶瓷的结构及电性能(英文)

采用传统的陶瓷烧结技术,通过添加0.15%(摩尔分数)CeO2,在1120℃烧结2h,成功制备了新型无铅压电陶瓷Ba0.9 Ca0.1 Ti1-x Snx O3,并且检测了陶瓷样品的微结构和电性能.XRD显示所有陶瓷样品均具有纯的钙钛矿结构,在室温下为典型的四方相,SEM显示适量添加锡离子可以提高陶瓷致密性.在室温下,锡离子改性的BaTiO3基压电陶瓷在x=0.02处显示了优异的压电、介电和铁电性能(d33=276 pC/N,kp=46%,εr=3678,tanδ=2.4%,Pr=18.2μC/cm2,EC=1.12 kV/mm).这些优异的检测结果证实适当添加锡离子能改善BaT iO3基压电陶瓷的电性能.     

PMSZT压电陶瓷的烧结工艺研究

研究保温时间对PMSZT压电陶瓷的相组成、显微结构及电性能的影响。结果发现,烧结温度1240℃保温1h时,密度达极值7．83g／cm^3。保温1h的试样,晶粒致密均匀,居里温度最低。随着保温时间的缩短或延长,居里温度增加。电性能在保温1h时达最佳,ε33^T/ε0=1700,d33=336pC/N,Kp=0.655,Qm=2200,tgδ=0.0030。     

Sm2O3掺杂(Ba0.7Ca0.3)TiO3-Ba(Zr0.2Ti0.8)O3无铅压电陶瓷的制备与性能

采用固相合成法制备了Sm2O3掺杂的(Ba0.7Ca0.3)TiO3-Ba(Zr0.2Ti0.8)O3(BCZT)无铅压电陶瓷.借助XRD、SEM等手段对该陶瓷的显微结构与电性能进行了研究.结果表明,Sm2O3的掺杂降低了BCZT无铅压电陶瓷的烧结温度并使居里温度点Tc从85℃提高到95℃.当Sm2O3掺杂量为0.02wt%～0.1wt%时,样品具有典型ABO3型钙钛矿结构.Sm2O3掺杂量为0.02wt%时,所得陶瓷样品具有最优综合电性能,其压电常数d33、机电耦合系数kp、机械品质因子Qm、介电损耗tanδ和介电常数εr分别为590 pC/N、0.52、43、1.3%和3372.     

Pb(Mg1/3Nb2/3)O3-Pb(Ni1/3Nb2/3)O3-Pb（ZrTi）O3大应变压电陶瓷的制备及性能研究

提升大应变压电陶瓷的应变量及温度稳定性,具有重要的实际意义。采用传统固相反应法,制备了（0.3-x）Pb(Mg_1/3Nb_2/3)O₃-xPb(Ni_1/3Nb_2/3)O₃-0.7Pb(Zr_0.42Ti_0.58)O₃(（0.3-x）PMN-xPNN-0.7PZT)大应变压电陶瓷。研究了PNN固溶量对陶瓷烧结性能、相结构、微观结构、介电性能、铁电性能、压电性能及温度稳定性的影响。结果发现,PNN固溶,引起晶格畸变,促进陶瓷烧结,同时改变准同型相界附近三方相与四方相含量。当x=0.06时,陶瓷具有最佳电学性能：机电耦合系数k_p、压电常数d₃₃、居里温度T_c、矫顽场E_c分别为0.682, 692 pC/N, 263℃, 880 V/mm;单极应变量在30 kV/cm电场及25℃温度条件下达到0.18%,并在25℃～180℃温度范围内,变化幅度<15%;退极化温度T_d≈260℃。     

Bi(Mg_(1/2)Ti_(1/2))O_3-PbTiO_3压电陶瓷体系介电与居里温度特性研究

采用传统固相法工艺制备了(1-x)Bi(Mg1/2Ti1/2)O3-x Pb Ti O3(BMT-x PT,0.34≤x≤0.44)陶瓷。研究发现,随着PT含量增加,试样结构由三方相逐渐转变为四方相结构,当0.36x0.40时,试样结构处于准同型相界(MPB)区。研究表明BMT组元是一种具有非铁电体特征的组分,随着PT含量减少,BMT-PT体系的居里温度减小,介电峰变得越来越不明显。通过研究BMT-PT体系组分与居里温度(TC)的关系可以看出:(1)PT含量为0.34~0.44时,TC随BMT含量变化实验值和Stringer的经验值差异较小,变化趋势一致;(2)BMT-PT体系居里温度最大值可能在x=0.73的附近,其居里温度最大值TC max约为550℃。     

PLN—3型压电陶瓷材料组成对压电参数温度稳定性的影响

在适当的工艺条件下，改变铌锂锆钛酸铅（PLN）三元系压电陶瓷材料组成中的锆钛比，加取代改性物及外加改性添加物，获得了高温稳定的PLN－3型压电陶瓷材料。该材料常温性能优良，高温稳定性好，200℃时相对25℃时的性能参数变化较小，介电常数变化小于45％，谐振频率变化小于2．5％，机电耦合系数变化小于－3％。本文在大量实验的基础上叙述了PLN材料组成与材料压电参数温度稳定性的关系，并对其改性作用机理进行了探讨。     

三元陶瓷Pb(In1/2Nb1/2)O3-Pb(Ni1/3Nb2/3)O3-PbTiO3准同型相界附近组分的介电、铁电和压电性能

铅基复合钙钛矿铁电材料广泛应用于机电传感器、致动器和换能器。二元铁电固溶体Pb(Ni_1/3Nb_2/3)O₃- PbTiO₃(PNN-PT)由于其在准同型相界(MPB)区域具有优异的压电、介电性能而备受关注。然而较大的介电损耗和较低的居里温度限制了其在高温高功率器件方面的应用。本研究通过引入Pb(In_1/2Nb_1/2)O₃ (PIN)作为第三组元改善PNN-PT的电学性能, 提高其居里温度; 通过两步法合成了MPB区域的三元铁电陶瓷Pb(In_1/2Nb_1/2)O₃- Pb(Ni_1/3Nb_2/3)O₃-PbTiO₃ (PIN-PNN-PT), 研究了其结构、介电、铁电和压电性能。制备的所有组分陶瓷具有纯的钙钛矿结构。随着PT含量的增加, 陶瓷结构从三方相转变为四方相。通过XRD分析得到了室温下PIN-PNN-PT体系的MPB相图。体系的居里温度由于PIN的加入得到了很大的提高, 更重要的是PIN的引入降低了PNN-PT体系的介电损耗和电导。MPB处的组分展现出了优异的电学性能, 室温下, 性能最优组分为0.30PIN-0.33PNN-0.37PT: d₃₃=417 pC/N, T_C=200 ℃, ε′= 3206, tanδ=0.033, P_r=33.5 μC/cm², E_C=14.1 kV/cm。引入PNN-PT的PIN第三组元使得体系的居里温度和压电性得到提高的同时降低了的介电损耗和电导率, 因此, PIN-PNN-PT三元铁电陶瓷在高温高功率换能器等方面具备一定的应用潜力。     

Sn层PMN——PZT三元系压电陶瓷低温稳定性和压电性能影响的研究

制备了６种不同Ｓｎ含量的ＰＭＮ－ＰＺＴ压电陶瓷试样,深入研究了Ｓｎ添加剂对压电材料压电等性能的影响,用ＺＰＡ分析了Ｓｎ在改性ＰＺＴ压电陶瓷中的存在形式。研究表明,Ｓｎ添加剂不仅能提高压电性能而且改善了压电陶瓷低温性能的稳定性     

锰掺杂Sr2-xCaxNaNb5O15（x=0.05～0.35）无铅压电陶瓷微观结构与电学性能的研究

采用传统陶瓷制备工艺制备了Mn掺杂的钨青铜结构无铅压电陶瓷Sr2-xCaxNaNb5O15+ywt%MnO2(x=0.05～0.35,y=0,0.3,0.5)(SCNN-M),并对SCNN-M陶瓷相组成、微观结构及介电、压电、铁电性能进行了研究.分析表明:Ca2+已进入Sr2NaNb5O15晶格之中形成固溶体;掺杂适量的锰,能够得到致密、单一的钨青铜结构陶瓷,有效降低烧结温度,促进晶粒长大,显著提高陶瓷的介电、压电、铁电性能.当x=0.05,添加0.5wt%的MnO2时,陶瓷具有较好的介电、压电和铁电性能:介电常数εr=2123,介电损耗tanδ=0.038,压电系数d33=190pC/N,机械品质因数Qm=1455,平面伸缩振动机电耦合系数Kp=13.4%,厚度伸缩振动机电耦合系数Kt=36.5%,剩余极化强度Pr=4.76μC/cm2,自发极化强度Ps=9.36μC/cm2,矫顽场Ec=12.68kV/cm,居里温度Tc=260℃.     

含铋层状结构陶瓷CaBi2Nb2O9的A位掺杂改性研究

利用固相反应法合成了Ca1-x(KLa)x/2Bi2Nb2O9(x=0～0.20)(xKLaCBNO)铋层状陶瓷,分析不同KLa掺杂量对CaBi2Nb2O9(CBNO)基陶瓷微观结构、介电、压电及电导性能的影响.XRD分析表明KLa的引入未改变CBNO陶瓷的单相结构.SEM和介电系数温度谱结果分别显示,KLa掺杂量的增加,细化尺寸趋于一致,而居里温度(Tc)从943℃降低至875℃,其峰值介电常数减小、峰值介电损耗增大.当掺杂量x=0.1时,样品的高温电阻率较纯CBNO显著升高,压电系数d33由5.2 pC/N提高到15.8 pC/N,居里温度高达870℃,说明A位(KLa)掺杂改性后的CBNO陶瓷在高温传感器等领域具有潜在的应用前景.     

SmAlO3-modified (K0.5Na0.5)0.95Li0.05Sb0.05Nb0.95O3 lead-free ceramics with a wide sintering temperature range

Lead-free ceramics (1 − x)(K_0.5Na_0.5)_0.95Li_0.05Sb_0.05Nb_0.95O₃-xSmAlO₃ (KNLNS-xSA) were prepared by conventional sintering technique. The phase structure, dielectric and piezoelectric properties of the ceramics were investigated. All compositions show a main perovskite structure, exhibiting room-temperature symmetries of tetragonal at x ≤ 0.0075, of pseudo-cubic at x = 0.0100. The Curie temperature of KNLNS-xSA ceramics decreases with increasing SmAlO₃ content. Moreover, the addition of SmAlO₃ can effectively broaden the sintering temperature range of the ceramics. The KNLNS-xSA ceramic with x = 0.0050 has an excellent electrical behavior of piezoelectric coefficient d₃₃ = 226 pC/N, planar mode electromechanical coupling coefficient k_p = 38%, dielectric loss tan δ = 3.0%, mechanical quality factor Q_m = 60, and Curie temperature T_C = 327 °C, suggesting that this material could be a promising lead-free piezoelectric candidate for piezoelectric applications.     

Effect of Pb(Fe1/2Nb1/2)O3 modification on dielectric and piezoelectric properties of Pb(Mg1/3Nb2/3)O3-PbZr0.52Ti0.48O3 ceramics

10 mol% Pb(Fe_1/2Nb_1/2)O₃ (PFN) modified Pb(Mg_1/3Nb_2/3)O₃-PbZr_0.52Ti_0.48O₃ (PMN-PZT) relaxor ferroelectric ceramics with compositions of (0.9 − x)PMN-0.1PFN-xPZT (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9) were prepared. X-ray diffraction investigations indicated that as-prepared ceramics were of pure perovskite phase and the sample with composition of x = 0.8 was close to morphotropic phase boundary (MPB) between rhombohedral and tetragonal phase. Dielectric properties of the as-prepared ceramics were measured, and the Curie temperature (T_c) increased sharply with increasing PZT content and could be higher than 300 °C around morphotropic phase boundary (MPB) area. At 1 kHz, the sample with composition of x = 0.1 had the largest room temperature dielectric constant ?_r = 3519 and maximum dielectric constant ?_m = 20,475 at T_m, while the sample with composition of x = 0.3 possessed the maximum dielectric relaxor factor of γ = 1.94. The largest d₃₃ = 318 pC/N could be obtained from as-prepared ceramics at x = 0.9. The maximum remnant polarization (P_r = 28.3 μC/cm²) was obtained from as-prepared ceramics at x = 0.4.     

非化学计量比对(K0.465Na0.465Li0.07)(Nb0.95Sb0.05)O3无铅压电陶瓷结构及性能的影响

通过传统固相合成工艺制备了(K0.465+xNa0.465+yLi0.07)(Nb0.95-zSb0.05)O3(x,y,z=-0.01～0.02)无铅压电陶瓷,研究了非化学计量比对陶瓷结构及压电性能的影响。结果表明符合化学计量比的陶瓷具有四方钙钛矿结构;在实验范围内,K和Nb的过量或少量均不会改变体系的相结构,而Na过量将会导致体系正交-四方相变温度升高到室温以上,并且正交-四方相变温度随y的增加而升高;过量添加约0.5%(摩尔分数)的K或Na便能补偿在高温烧结时的碱金属元素的挥发损失,进而提高陶瓷的压电性能;该体系陶瓷的组分在较大范围内变化时(如当y=z=0时,x=0～0.02;当x=z=0时,y=0～0.01;以及当x=y=0时,z=-0.01～0.005),仍然能保持d33>200pC/N和kP>40%这样较好的性能。上述结果不仅有利于在研究中材料制备工艺的重复,而且有利于当材料在器件应用时所面临的规模化生产。     

0.08Pb(Fe1/3Sb2/3)O3-yPbTiO3-(1-0.08-y)PbZrO3压电陶瓷性能研究

合成了钙钛矿结构的0.08Pb(Fe1/3 Sb2/3)O3-yPb-TiO3-(1-0.08-y)PbZrO3三元系压电陶瓷材料,测量并计算了不同y值时的压电常数(d33)、机电耦合系数kp、k33)、机械品质因数(Qm)以及极化前后的介电常数(εT33/ε0),对实验现象进行了简单的讨论,得出一些有益的结论;实验结果表明当选取合适的y值时可以获得压电性能良好的压电材料,如y=0.45时材料的平面机电耦合系数kp、纵向机电耦合系数k33和压电常数d33分别达到0.64×10-12C/N、0.72×10-12C/N和365×10-12C/N.     

Thickness dependence of structural and ferroelectric properties of sol-gel Pb(Zr0.56Ti0.44)0.90(Mg1/3Nb2/3)0.10O3 films

Sol-gel Pb(Zr_0.56Ti_0.44)_0.90(Mg_1/3Nb_2/3)_0.10O₃ (PZT-PMN) films were prepared onto the Ti/Pt/Ti bottom electrode by multilayer spin coating. The film thickness ranged from 0.22 to 0.88 μm. The Pt top electrodes were deposited on the PZT-PMN films by DC sputtering. The structural and ferroelectric properties of PZT-PMN films were investigated as a function of film thickness by X-ray diffraction (XRD), scanning electron microscopy (SEM), cross-sectional transmission electron microscopy (XTEM), and by measuring the relative permittivity. The film retains the tetragonal perovskite structure with the [111] and [100] preferred orientations perpendicular to the film surface independent of film thickness. The [100] texture increases with increasing film thickness although the [111] texture is always predominant. The film consists of columnar grains. The average grain size is nearly independent of film thickness. The surface layer containing fine grains about 30 nm in diameter is induced on the top of the film. As the film thickness exceeds 0.44 μm, the number of the fine grains decreases remarkably. The crystalline interface layer about 10 nm thick is formed between the film and the bottom electrode. This interface layer is composed of Pt, Pb, Zr, Ti and O, while it is rich in Ti and deficient in Pb and O as compared with the inside of the film. The measured relative permittivity of the film increases with increasing film thickness, following the low permittivity interface model. On the basis of this model, the relative permittivity is estimated to be 3200 for the intrinsic PZT-PMN film, 750 for the surface layer and 50 for the interface layer.     

Effects of Fe2O3 doping on the microstructure and piezoelectric properties of 0.55Pb(Ni1/3Nb2/3)O3-0.45Pb(Zr0.3Ti0.7)O3 ceramics

0.55Pb(Ni_1/3Nb_2/3)O₃-0.45Pb(Zr_0.3Ti_0.7)O₃(PNN-PZT) ceramics with different concentration of xFe₂O₃ doping (where x = 0.0, 0.8, 1.2, 1.6 mol%) were synthesized by the conventional solid state sintering technique. X-ray diffraction analysis reveals that all specimens are a pure perovskite phase without pyrochlore phase. The density and grain size of Fe-doped ceramics tend to increase slightly with increasing concentration of Fe₂O₃. Comparing with the undoped ceramics, the piezoelectric, ferroelectric and dielectric properties of the Fe-doped PNN-PZT specimens are significantly improved. Properties of the piezoelectric constant as high as d₃₃ ~ 956 pC/N, the electromechanical coupling factor k_p ~ 0.74, and the dielectric constant ε_r ~ 6095 are achieved for the specimen with 1.2 mol% Fe₂O₃ doping sintered at 1200 °C for 2 h.     

Depolarization temperature and piezoelectric properties of Na1/2Bi1/2TiO3-Na1/2Bi1/2(Zn1/3Nb2/3)O3 ceramics by two-stage calcination method

A new group of NBT-based lead-free piezoelectric ceramics, Na_1/2Bi_1/2TiO₃-Na_1/2Bi_1/2(Zn_1/3Nb_2/3)O₃, was synthesized using the two-stage calcination method and depolarization temperatures and piezoelectric properties were also investigated. The XRD analysis showed that the ceramics system had a morphotropic phase boundary (MPB) between the rhombohedral and the tetragonal structure. The highest piezoelectric properties of d ₃₃ = 97 pC/N and k _t = 0·46 were obtained near MPB compositions. Furthermore, the depolarization temperatures near MPB compositions were slightly decreased and the lowest T _d was maintained at 210°C.     

改性偏铌酸铅高温压电陶瓷材料的研究

偏铌酸铅是一种性能很有特色却又制备困难的高温压电陶瓷材料，而采用少量Ｍｅ＾２＋置换和微量稀有元素氧化物添杂方法，获得了压电性能和工艺性能均十分优良的改性偏铌酸铅高温压电陶瓷材料，并以热力学熵稳定原理，定性地解释了少量置换与微量添杂对稳定铁电相的作用，同时也对这种压电陶瓷材料的高温压电特性和高温下的应用进行了研究与试验，结果表明，这种材料是一种可以在４００℃下应用的高温压电陶瓷材料。     

CeO_2掺杂对Pb_(0.92)Sr_(0.06)Ba_(0.02)(Sb_(2/3)Mn_(1/3))_(0.05)Zr_(0.48)Ti_(0.47)O_3基压电陶瓷相结构及性能的影响

采用传统固相烧结法制备Pb_(0.92)Sr_(0.06)Ba_(0.02)(Sb_(2/3)Mn_(1/3))_(0.05)Zr_(0.48)Ti_(0.47)O_3∶xCeO_2(简称PSBSM-PZT)压电陶瓷样品。研究不同CeO_2掺杂含量对PSBSM-PZT基陶瓷样品的物相结构、微观形貌、压电及介电性能的影响。结果表明:当CeO_2掺杂量x≤0.5%(质量分数,下同)时,陶瓷样品均为纯的钙钛矿结构。随着CeO_2掺杂含量的增加,陶瓷样品中四方相结构逐渐向三方相结构转变。随着CeO_2掺杂含量的进一步增加,陶瓷中出现焦绿石相,虽然陶瓷中已经出现焦绿石相,但是样品仍没有完全转变为三方相陶瓷;CeO_2掺杂具有细化晶粒的作用,当x=0.25%时样品晶粒晶界清晰,晶粒之间的结合相对致密,晶界处气孔率低,陶瓷断裂方式以沿晶断裂为主;当x=0.25%时,陶瓷样品获得最佳的压电与介电性能:d_(33)=346pC/N,k_p=0.60,Q_m=1396,ε_r=1309,tanδ=0.474%。