流延法制备SrBi4Ti4O15压电陶瓷

采用同相法和熔盐法（KCl-NaCl作为熔盐）合成SrBi4Ti4O15陶瓷粉体，用模板晶粒定向技术（TGG）获得具有各向异性晶粒定向排列的SrBi4Ti4O15陶瓷。实验中，着重探讨了流延成型的工艺。分析表明，以预烧温度900℃模板和900℃固相粉体在1200℃烧结合成制得的流延片的取向度（79．52％）较高，定向排列程度较高，但由于实验过程中，添加了大量有机溶剂，所以有许多缺陷存在。以900℃模板在1200℃烧结的流延陶瓷片的介电性能最好.     

CaCu3-xMnxTi4O12陶瓷的介电性能研究

本文利用固态反应法制备了CaCu3-xMnxTi4O12(x=0,0.2,0.4,0.6,0.8,1.0)陶瓷,并分析探讨了MnO添加量对其介电性能的影响。研究结果表明,MnO的添加有助于CaCu3Ti4O12相生成,且在高MnO添加的情况下所得陶瓷晶粒尺寸较小。MnO的添加对CaCu3Ti4O12的介电性能有非常不好的影响,少量的添加就会导致其介电常数由10000多降至只有数百。在1000Hz前MnO的添加会使陶瓷的介电损耗大幅上升,这表明MnO添加有降低电阻的效果。     

锰掺杂Bi0.5Na0.41K0.09TiO3+xMnO2陶瓷的电学性能

采用传统陶瓷工艺、按照Bi0.5Na0.41K0.09TiO3+xMnO2的配方进行称量,其中x=0、0.005、0.01、0.03、0.05,共5个组分,制备出了无铅压电陶瓷坯体,在其烧结温度下进行烧结,制备了新型压电陶瓷Bi0.5Na0.41K0.09TiO3+xMnO2,并研究了该体系陶瓷的电学性能,测试其压电常数(d33)、机电耦合系数(Kp)、机械品质因素(Qm)、介电常数(εr)、介质损耗Tanδ及其电滞回线,并分析掺杂量对其性能的影响。     

Eu掺杂对Bi5Fe0.5Co0.5Ti3O15陶瓷电磁性能的影响

用传统固相烧结法制备了Bi5–xEuxFe0.5Co0.5Ti3O15(BEFCT–x:x=0,0.35,0.55,0.85)陶瓷样品,对比研究了它们的结构和电磁性能。X射线衍射分析表明:掺杂未导致明显杂相,材料的剩余极化(2Pr)随掺杂量的增加呈先增加后减小的变化趋势,在Eu掺杂量为0.55时,材料的2Pr达到最大值,为11.2μC/cm2,升幅达143%,可以由Eu掺杂导致氧空位的抑制和铋氧层的破坏所形成的竞争机制解释。随Eu含量的增加,材料的剩余磁化单调上升,最大达到0.28 A m2/kg,比未掺杂时增加了2个数量级,从晶格失配、耦合增强以及共生结构等方面的综合效果解释了这一现象。材料的介电温度谱显示,Eu掺杂未明显损害材料的热稳定性,Eu掺杂所导致的介电损耗行为可能与氧空位或其他点缺陷有关联。     

Co、Mn共掺杂铋层状Na_(0.5)Bi_(4.5)Ti_4O_(15)无铅压电陶瓷的显微结构及电性能

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。     

Mg掺杂对Li4Ti5O12电化学性能的影响

采用高温固相法合成尖晶石型Li4Ti5O12电极材料,研究了镁掺杂对其电化学性能的影响。通过扫描电镜(SEM)、X射线衍射(XRD)手段对材料进行表征,恒电流充放电考察了掺杂产物的电化学性能。Li4-xMgxTi5O12(x=0.1)具有良好的电化学性能和粒度分布,在0.2 C,1 C,3 C,5 C倍率下充放电时,首次充电比容量依次为164.2,158.6,150.8,144.5 mAh/g。结果表明掺杂镁的Li4Ti5O12,其高倍率得到了改善。     

铁钕掺杂K0.5Na0.5NbO3陶瓷的压电介电性能

采用传统陶瓷制备技术制备了新型的K0.5Na0.5NbO3+0.2%molFe2O3+x%molNd2O3压电陶瓷,研究了该体系陶瓷的压电性能及介电性能。研究结果表明,在烧结温度为1120℃、4 h时,该体系陶瓷均具有相对较好的电学性能,并在x为0.2时性能最佳,其压电常数d33为125pC/N,机电耦合系数Kp为37%,机械品质因素Qm为155,介电常数εr为561,介质损耗tanδ为0.08。     

Ca,Sr掺杂BNT-BT压电陶瓷结构与性能研究

采用传统的电子陶瓷制备工艺制备了一系列0.93Bi05Na05Tio3-0.07(Ba1-xAx)TiO3(简写为BNBAT100x;其中A=Ca,sr,x:0.02,0.04,0.06,0.08,0.10)陶瓷,研究了陶瓷的结构、介电、压电性能变化特征.XBD分析表明,陶瓷样品均形成了单一的钙钛矿结构固溶体.陶瓷的介电、压电性能受Ca,Sr含量的影响显著.所有陶瓷样品表现出弥散相变特征.当x<0.08时,BNBCT陶瓷的介电常数大干BNBST陶瓷,同时,BNBCT陶瓷室温介电常数在x=0.04时达到最大.而BNBST陶瓷此时具有最小的室温介电常数.陶瓷的压电性能受Ca,Sr含量的显著影响,当Ca含量为6mol%时,压电常数(d33)和平面机电耦合(kp)达到最大,分别为1 40.5 pc/N和1 9.7%.而当Sr含量为4mol%时,BNBST陶瓷的压电常数(d13)达到最大为1 39.8pC/N.此时平面机电耦合(kp)为1 8.9%.     

Co2O3掺杂对(Na0.8K0.2)0.5Bi0.5TiO3陶瓷结构与电性能的影响

采用传统固相法制备了(Na0.8K0.2)0.5Bi0.5TiO3+xmol%Co3+(BNKT-xCo,x=0-8)无铅压电陶瓷,研究了Co2O3掺杂对BNKT陶瓷的显微结构与电学性能的影响。研究表明:适量的Co2O3掺杂促进了晶粒生长,纯BNKT陶瓷样品在介电温谱上有2个介电反常峰Td和Tm,Co2O3掺杂后使所有陶瓷样品的第一个介电反常峰Td消失,表明Co3+抑制铁电-反铁电相变。室温下样品的介电、铁电和压电性能表明Co2O3起硬性掺杂效应。当x=7时陶瓷样品电性能最佳,其中机械品质因子Qm=498,介电损耗tanδ=2.3%(1kHz),压电常数d33=103pC/N,平面机电耦合系数kp=27%。     

(1-x)Bi0.5(Na0.8K0.2)0.5TiO3-xKSbO3压电陶瓷的制备及性能研究

采用传统固相法制备了新型(1-x)Bi0.5(Na0.8K0.2)0.5Ti O3-xKSbO3无铅压电陶瓷,利用XRD、SEM等测试技术表征了该陶瓷的晶体结构、表面形貌、压电和介电性能。研究结果表明,在所研究的组成范围内陶瓷材料均能形成纯的钙钛矿固溶体。在室温下,当KSb O3的掺杂量为1%时,该体系表现出较好的介电性能:εr和tanδ分别为2 231和0.055。     

Enhanced piezoelectric performance in Na0.5Bi4.5Ti4O15-based bismuth-layered ceramics by Nb/Mn doping modification

In this work, Na_0.5Bi_4.5Ti_3.94–xMn_0.06Nb_xO_15+y bismuth-layered ferroelectric ceramics were prepared by a solid-state reaction method. The effect of Nb⁵⁺ content on crystal morphology, electrical properties, and piezoelectric performance were systematically investigated. The results show that the introduction of Nb⁵⁺ into Na_0.5Bi_4.5Ti_3.94–xMn_0.06Nb_xO_15+y ceramics to replace Ti⁴⁺ increases the ratio of b/a lattice parameter, leading to the TiO₆ octahedral distortion and the structural transformation tendency from the orthorhombic to tetragonal phase, which facilitates dipole movements of Na_0.5Bi_4.5Ti_3.94–xMn_0.06Nb_xO_15+y ceramics. Therefore, the ferroelectric properties of Na_0.5Bi_4.5Ti_3.94–xMn_0.06Nb_xO_15+y ceramics are improved, and an enhanced piezoelectric coefficient of 30 pC/N combining great temperature stability with d₃₃ value higher than 25 pC/N in the temperature range of 25°C–450°C has been realized in Na_0.5Bi_4.5Ti_3.94–xMn_0.06Nb_xO_15+y ceramics with x = 0.08 mol. Our work provides a good model for designing lead-free ultrahigh Curie temperature piezoelectric devices that can be practically applied in extremely harsh environments.     

Na2xCa1-xBi4Ti4O15介电陶瓷的制备及其介电性能的研究

采用固相烧结法制备了Na 1掺杂的CaBi4Ti4O(15CBT)铋系层状钙态矿无铅介电陶瓷。利用XRD、SEM和宽频LCR数字电桥分析了掺杂量、烧结温度等因素对CBT陶瓷晶相、微观形貌及介电性能的影响。研究表明,采用860℃预烧,保温3小时,1150℃终烧,保温1h的烧结工艺,Na2xCa1-xBi4Ti4O15(x=8mol%)的介电陶瓷致密性好、结晶性好,具有良好的介电性能。     

High‐temperature piezoelectric properties of 0‐3 type CaBi4Ti4O15:x wt%BiFeO3 composites

The 0‐3 type CaBi₄Ti₄O₁₅:30 wt%BiFeO₃ composite shows much better high‐temperature piezoelectric properties than the single‐phase CaBi₄Ti₄O₁₅ or BiFeO₃ ceramics. The composite with 0‐3 type connectivity exhibits a high density of 7.01 g/cm³, a saturated polarization of 21.5 μC/cm² and an enhanced piezoelectric d₃₃ of 25 pC/N. After the poled composite was annealed at 600°C, its d₃₃ is 21 pC/N at room temperature. Resistance of the composite decreases slowly from 10⁹ ohm at 20°C to ~10⁵ ohm at 500°C. Furthermore, the poled composite shows strong radial and thickness dielectric resonances at 20°C‐500°C.     

组分影响CaBi4Ti4O15介电性能的研究

采用正交设计试验法研究了配方对CaBi4Ti4O15(CBT)铁电陶瓷介电性能的影响,得到了影响CBT陶瓷介电性能的主次因素以及各因素水平影响其性能的趋势,进而得到了综合性能佳的CBT陶瓷.探讨了各组分对CBT陶瓷介电性能影响的机理,为CBT陶瓷材料的改性研究提供了依据.     

Enhanced electrical properties in W/Cu co-doped CaBi2Nb2O9 high-temperature piezoelectric ceramics

CaBi₂Nb₂O₉ (CBN)-based high-temperature piezoelectric ceramics with the formula of CaBi₂Nb_2−x(W_3/4Cu_1/4)_xO₉ were prepared via the traditional solid-state reaction method. Both the bulk microstructure and the electrical performance of the W/Cu co-doped CBN-based ceramics were systematically investigated. The results indicated that the W/Cu incorporation into the Nb-site altered the crystal structure, which enhanced the piezoelectricity and resistivity. The ceramic with the composition CaBi₂Nb_1.96(W_3/4Cu_1/4)_0.04O₉ exhibited good performance with a high d₃₃ (~14 pC/N) and T_C (~939℃). Moreover, the ceramic exhibited a good electrical resistivity (ρ) of 4.91 × 10⁵ Ω·cm and a low dielectric loss (tanδ) of 0.1 at 600℃. Furthermore, the ceramic that was annealed at 900℃ for 2 h presented a d₃₃ value of 13 pC/N, thus indicating good thermal stability of the piezoelectric properties. All these results confirm that the CaBi₂Nb_1.96(W_3/4Cu_1/4)_0.04O₉ ceramic may act as a potential promising candidate for piezoelectric device applications in high-temperature environments.     

铈和锶复合掺杂对Bi_4Ti_(2.92)Nb_(0.08)O_(12.04)高温无铅压电陶瓷的影响

采用固相法制备了Ce和Sr复合掺杂的Bi4Ti2.92Nb0.08O12.04(BTN+0.5x%CeO2+0.5x%SrCO3,0≤x≤1.5,质量分数)铋层状高温无铅压电陶瓷,研究了不同含量的Ce和Sr掺杂对BTN系陶瓷微观结构及电性能的影响。结果表明:样品均为单一的铋层状结构相,Ce和Sr的引入明显提高了陶瓷的压电性能。当掺杂量x=0.9时,样品具有最佳性能:压电常数d33=29pC/N,平面机电耦合系数kp=8.77%,介电损耗tanδ=0.13%,剩余极化强度Pr=15.87μC·cm-2和Curie温度TC=627℃。此外,该组分陶瓷样品具有良好的压电稳定性,表明该材料在高温领域下具有良好的应用前景。     

Structural and electric properties of Ce-doped Na0.5Bi4.5Ti4O15 piezoceramics with high Curie temperatures

Na_0.5Bi_4.5-xCe_xTi₄O₁₅ (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) lead-free piezoelectric ceramics with high Curie temperatures are fabricated using the conventional solid-phase method. The effects of the Ce content on the phase structures, morphologies, and electrical properties of the Na_0.5Bi_4.5-xCe_xTi₄O₁₅ ceramics are systematically investigated. The appropriate content of Ce increases b/a and c/a and induces the distortion of the crystal structure. The increased b/a leads to a transverse asymmetry of the Na_0.5Bi_4.5-xCe_xTi₄O₁₅ ceramics, which facilitates the dipole flipping, thus enhancing the piezoelectric properties (d₃₃ = 20 pC/N). Although the improved c/a increases the degree of tetragonality of the Na_0.5Bi_4.5-xCe_xTi₄O₁₅ ceramic, which decreases the Curie temperature (T_C), the T_C values of all samples are higher than 600°C, considerably higher than the practical application temperature. The Ce doping significantly reduces the dielectric loss of the sample and increases its dielectric performance. The improvements in electric properties by the cerium doping can expand its use in high-temperature environments for oilfield logging, aerospace, and military applications.     

压电陶瓷PZN-PZT对压电复合材料性能的影响

本研究采用固相烧结法合成了PZN-PZT压电陶瓷粉体,并用XRD分析了其晶相组成。将PZN-PZT陶瓷粉体与PVDF复合,制备出PZN-PZT/PVDF0-3型压电复合材料,研究了陶瓷质量分数对复合材料铁电性、介电性及压电性的影响。结果表明,复合材料的铁电性、介电性和压电性能随陶瓷含量的增加而增强,当陶瓷含量为90%时,复合材料的剩余极化强度Pr达到5.27μC·cm-2,矫顽场EC为76kV·cm-1,介电常数εr为188,介电损耗tanδ为0.065,压电常数d33则达到33.4pC/N。     

Influence of Mn Ions’ Insertion in Pseudo-Tetragonal Phased CaBi4Ti4O15-Based Ceramics for Highly Efficient Energy Storage Devices and High-Temperature Piezoelectric Applications

In the present era of advanced technology, the surge for suitable multifunctional materials capable of operating above 300 °C has increased for the utilization of high-temperature piezoelectric devices. For this purpose, a pseudo-tetragonal phased CaBi₄Ti_3.98 (Nb_0.5Fe_0.5)_0.02O₁₅:xwt%MnO₂ (CBTNF:xMn), with x = 0–0.20, ceramic system has been engineered for the investigation of structural, ferroelectric, dielectric and high-temperature-dependent piezoelectric properties. XRD analysis confirms that low-content Mn-ion insertion at the lattice sites of CBTNF does not distort the pseudo-tetragonal phase lattice of CBTNF:xMn ceramics, but enhances the functional behavior of the ceramic system, specifically at x = 0.15 wt%Mn. Compared to pure CBT and CBTNF ceramics, CBTNF:0.15Mn has demonstrated a highly dense relative density (~96%), a saturated polarization (P_S) of 15.89 µC/cm², a storage energy density (W_ST) of ~1.82 J/cm³, an energy-conversion efficiency (ƞ) of ~51% and an upgraded piezoelectric behavior (d₃₃) of 27.1 pC/N at room temperature. Sharp temperature-dependent dielectric constant (ε_r) peaks display the solid ferroelectric behavior of the CBTNF:0.15Mn sample with a Curie temperature (T_C) of 766 °C. The thermally stable piezoelectric performance of the CBTNF:0.15Mn ceramic was observed at 600 °C, with just a 0.8% d₃₃ loss (25 pC/N). The achieved results signify that multi-valence Mn ions have effectively intercalated at the lattice sites of the pseudo-tetragonal phased CBTNF counterpart and enhanced the multifunctional properties of the ceramic system, proving it to be a durable contender for utilization in energy-storage applications and stable high-temperature piezoelectric applications.