共查询到19条相似文献,搜索用时 62 毫秒
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采用传统固相法制备了无铅压电陶瓷Bi0.5(Na0.825K0.175)0.5TiO3+xFe2O3(x为质量分数,0、0.1%、0.3%、0.5%、0.7%、1.0%、1.5%)(简写BNKTF-x),利用X射线衍射(XRD),和扫描电子显微镜(SEM)等分析表征了该体系陶瓷的结构、介电与压电性能。XRD测试表明,在1 180℃、2 h的烧结条件下,当铁的质量分数小于1.0%时,陶瓷呈现单一相的钙钛矿结构。所有陶瓷晶粒大多呈四方晶形,晶界明显。增加铁的含量有利于晶粒生长。此外,铁的加入也使陶瓷样品气孔率降低,当铁的质量分数在0.3%左右时陶瓷的致密性最好。BNKTF-0.1%体系陶瓷具有较好的电学性能:d33=145 pC/N,kp=0.28,εr=869,tanδ=0.032,Qm=106。 相似文献
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采用XRD,SEM,HRTEM等分析技术对(1-x)(Bi1/2Na1/2)TiO3-xBaTiO3(简称为BNBT)(x为0.04,0.06,0.08,0.10)进行了结构与性能的研究,并主要分析了x为0.06,即0.94(Bi1/2Na1/2)TiO3-0.06BaTiO3(简称为BNBT6)在不同烧结温度下的结构形态及其对性能的影响.结果表明:(1-x)(Bi1/2Na1/2)TiO3-xBaTiO3系统具有很窄的烧结范围.另外,加入过量的Ba2+,能起到阻碍晶粒长大的作用. 相似文献
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详细探讨了在制备(Bi1/2Na1/2)TiO3 BaTiO3(abbr.BNBT)系无铅压电陶瓷的过程中,合成条件Ty和烧结温度Ts对材料压电介电性能的影响,确定了较好的制备BNBT系压电陶瓷的工艺条件,并且系统地研究了(1-x)·(Bi1/2Na1/2)TiO3 xBaTiO3(x=0 02、0 04、0 06、0 08、0 10)的性能。XRD结构分析发现系统的相界在x=0 06,此时d33等压电介电性能参数达到最佳值。 相似文献
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作为一种具备优异介电性能的电介质材料,压电材料还具备优异的铁电性能,且可以与铁磁性进行耦合,已经成为一种重要的声、光、电、磁等敏感性较强的功能材料。在环境保护日益重视的社会环境下,本文对环境友好型无铅压电陶瓷的性能研究进行总结与分析,了解钛酸铋钠基无铅压电陶瓷研究的实质性进展,为使用问题的解决打下良好的基础。 相似文献
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采用固相法制备了(Na1-xKx0.5)Bi0.5YiO3-xSrTiO3-0.3Mn系无铅压电陶瓷,研究了该系统的微观结构和压电性能。XRD分析表明所得陶瓷样品在室温下均为三方、四方共存的钙钛矿结构,随着Sr的增加,三方相减少,四方相增加。SEM图谱显示各样品颗粒均匀、具有规则的外形、晶界明显,并且少量Sr的加入使样品更加致密化。该体系样品具有优异的压电性能,在Sr含量为0.02时,压电常数如、平面机电耦合系数k,和厚度机电耦合系数kt同时达到最大值,分别为171pC·N^-1、33.1%和30.5%,Sr具有“软性”添加物的作用 相似文献
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采用传统压电陶瓷固相合成法制得了纯钙钛矿相的( 1 -x) (Bi0 5Na0 5 )TiO3 -xBaTiO3 (x=0 02, 0 04,0 06, 0 08, 0 10) (简写作BNBT)系无铅压电陶瓷。研究了1kHz条件下室温到400℃的温度范围内BNBT试样的介电温谱以及3种不同频率下(1、10、100kHz)BNBT-6试样的介电温谱,发现材料在研究组成范围内均为弛豫型铁电体。采用HRTEM研究了该系统的畴结构,表明BNBT钙钛矿结构铁电体的介电性能与复合离子的有序无序排列密切相关,纳米尺度有序微畴对介电弛豫起着重要作用。 相似文献
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采用电子陶瓷法制备出(1-x)Bi1/2Na1/2TiO3-xBaTiO3(简写BNBT)无铅压电陶瓷,其中x=0.08,0.1,0.2,0.3,0.4。XRD分析结果表明所制备的样品都生成了纯的钙钛矿结构,并且都为四方相。同时利用电子探针显微镜(EPM)分析技术,研究了BNBT压电陶瓷的形貌。并通过测量样品的压电介电常数,发现所研究的样品的机械品质因数(Qm)在56-74之间,平面机电耦合系数(kp)在0.16左右,频率常数(NФ)在3000左右,并且随着x的增大相对介电常数εT33/ε0逐渐变小;介质损耗tanδ先减小后增大,当x=0.20时出现最小值tanδmin=0.03018;而压电常数d33则先增加后减小,在x=0.10时有最大值d33max=138。从综合性能来看,当x=0.20时性能最好,εT33/ε0=881,tanδ=0.03018,d33=115。 相似文献
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Ping Peng Hengchang Nie Chan Zheng Genshui Wang Xianlin Dong 《Journal of the American Ceramic Society》2021,104(6):2610-2620
Ceramic-based dielectric capacitor are highly suitable for pulsed power applications due to their high power density and excellent reliability. However, the ultrahigh applied electric field limit their applications in integrated electronic devices. In this work, (1−x){0.96(Bi0.5Na0.5)(Ti0.995Mn0.005)O3-0.04BiAlO3}-xNaNbO3 (BNT-BA-xNN, x = 0, 0.04, 0.08, 0.12, and 0.16) ternary ceramics were designed to achieve excellent energy storage properties. It was found that the introduction of NaNbO3 (NN) effectively increase the difference (ΔP) between Pmax and Pr, resulting in an obvious enhancement of the energy storage properties. High recoverable energy storage density, responsivity, and power density, that is, Wrec = 2.01 J/cm3, ξ = Wrec/E = 130.69 J/(kV⋅m2), and PD = 25.59 MW/cm3, accompanied with superior temperature stability were realized at x = 0.14 composition. In addition, the thermal stable dielectric properties of the sample can be prominently improved with increasing NN content. The temperature coefficient of capacitance (TCC) of x = 0.16 composition is lower than 15% over the temperature range from 49°C to 340°C, with a high dielectric permittivity of 1647 and a low dielectric loss (0.0107) at 150°C. All these features show that the BNT-BA-xNN ceramics are promising materials for energy storage application. 相似文献
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以Bi(NO3)3·5H2O、Ti(OC4H9)4为原料,无水乙醇作溶剂,采用溶剂热法在常压下合成了Bi0.5Na0.5TiO3(简称为BNT)纳米粉体.通过X射线衍射(XRD)和扫描电子显微镜(SEM)对BNT粉体进行了表征.并在常压溶剂热条件下研究了影响BNT晶体生长和形貌的主要因素.实验结果表明:反应温度为100 ℃,保温时间为2.5 h,NaOH浓度为12 mol·L-1,650 ℃下煅烧2 h时,能制备出单一的BNT粉体,且制得粉体的粒径尺寸约为100 nm. 相似文献
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掺杂Co2O3对Na0.5Bi0.5TiO3基压电陶瓷性能的影响 总被引:1,自引:1,他引:0
通过固相法合成Na0.5Bi0.5TiO3+xmol%Co3+(简写为:NBT-xC)体系无铅压电陶瓷,并对其相结构、压电、介电及铁电性能进行了研究.XRD分析结果表明,所有组成均形成三方钙钛矿结构.SEM扫描电镜照片显示Co2O3的引入有利于晶粒长大,提高致密度.随着Co含量的增加,陶瓷的压电常数d33,机电耦合系数Kp都略有下降,机械品质因素Qm有明显提高,在x=3时达到极大值:0m-934,同时介电损耗出现极小值:tgδ=0.02(1kHz),综合得出Co离子起"硬性掺杂"作用. 相似文献
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Mengmeng Lun Wei Wang Zhifeng Xing Zhong Wan Wanying Wu Hanzhao Song Yinzhen Wang Wei Li Benli Chu Qinyu He 《Journal of the American Ceramic Society》2019,102(9):5243-5252
The Eu3+-modified Bi0.5Na0.5TiO3 (BNT) ceramics have been fabricated by the solid-state reaction method. The impact of Eu3+ doping on the structure, photoluminescence, and electrical properties has been studied by XRD, SEM, PL spectra, and LCR meter. X-ray diffraction analysis reveals that the crystal structure of the samples is well matched with the trigonal perovskite, and the optimal temperature of presintering is 880°C. The Eu3+-doped BNT ceramics show excellent red fluorescence at 614 nm corresponding to the 5D0→7F2 transition of Eu3+ under 466 nm excitation and relatively long fluorescence lifetime. The BNT-0.02Eu ceramic density is up to 5.68 g/cm3 and the relative density is up to 94.6% with sintering temperature 1075°C. The piezoelectric constant (d33) of samples has been significantly improved up to 110 pC/N by Eu3+ doping. The BNT-0.03Eu ceramic presintered at 880°C and sintered at 1050°C has good dielectric properties and excellent luminescence properties. Eu3+-doped BNT ceramics make it potential applications for novel integrated electro-optical and multifunctional devices. 相似文献
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Yingchun Su Xuefan Zhou Guoliang Xue Hang Luo Dou Zhang 《Journal of the American Ceramic Society》2023,106(6):3525-3536
In this work, (1 − x)(0.94Na0.5Bi0.5TiO3–0.06BaTiO3)–xKTaO3 (x = 0–0.30) ceramics are developed for dielectric capacitor applications. The introduction of KTaO3 from x = 0 to 0.30 increases the tolerance factor t from 0.984 to 1.005 and causes the decrease of ferroelectric rhombohedral phase in the ceramics. Besides, a gradual structural change toward a higher symmetry can be detected, accompanied by the obvious domain refinement. In the aspect of electrical property, the strengthened dielectric relaxation leads to the greatly enhanced thermal stability of dielectric response. The decline in Ts from 98 to −96°C causes a significant widening of the low-temperature region with temperature-stable dielectric constant εr and low dielectric loss tan δ. The x = 0.30 ceramic shows a high εr (25°C) of 1094 with the temperature coefficient of capacitance ≤±15% over −70 to 200°C, which exceeds the X9R standard. Meanwhile, tan δ is less than 0.02 in a wide temperature range of −35 to 300°C. In addition, the ultrafine grain size of 290 nm, large bandgap of 3.22 eV, and high resistance of the x = 0.30 ceramic contribute to its electrical breakdown strength. A linear-like P–E loop with the large discharged energy density WD ∼ 3.50 J/cm3 and high energy efficiency η ∼ 90.1% is obtained under 28 kV/mm at room temperature. The thermal stability of the energy storage performance is also satisfactory with the variation of WD less than 15% over −40 to 200°C, and the η is higher than 85%. 相似文献
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Qiumei Wei Lovro Fulanovic Kodumudi Venkataraman Lalitha Mupeng Zheng Yudong Hou Mankang Zhu Linjing Liu Yunfei Chang Rui Xue 《Journal of the American Ceramic Society》2022,105(5):3312-3321
Innovative cooling technologies are recognized by many industries as a crucial part of their system design. A large electrocaloric effect (ECE) and extended working temperature are the key issues hindering the realization of electrocaloric refrigeration technology. In this work, large ECE (ΔT = 0.8–0.9°C @ 4 kV/mm) with an ultrawide temperature span from 30 to 120°C is noted for lead-free (Na1/2Bi1/2)0.80Sr0.20(Zn1/3Nb2/3)xTi1-xO3 ceramics. The excellent ECE performance can be ascribed to the evolution of polar nanoregions. Our work suggests that this material is promising for applications in solid-state refrigeration systems with a broad range of operating temperatures. 相似文献
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Microstructure and piezoelectric properties of textured (Na0.84K0.16)0.5Bi0.5TiO3 lead-free ceramics
《Journal of the European Ceramic Society》2007,27(12):3453-3458
Textured (Na,K)0.5Bi0.5TiO3 ceramics were fabricated by reactive-templated grain growth in combination with tape casting. The effects of sintering conditions on the grain orientation and the piezoelectric properties of the textured (Na,K)0.5Bi0.5TiO3 ceramics were investigated. The results show that the textured ceramics have microstructure with plated-like grains aligning in the direction parallel to the casting plane. The ceramics exhibit {h 0 0} preferred orientation and the degree of orientation is larger than 0.7. The degree of grain orientation increases with the increasing sintering temperature. The textured ceramics show anisotropy dielectric and piezoelectric properties in the directions of parallel and perpendicular to the casting plane. The ceramics in the perpendicular direction exhibit better dielectric and piezoelectric properties than those of the nontextured ceramics with the same composition. The optimized sintering temperature is 1150 °C where the maximum d33 of 134 pC/N parallel to casting plane, the maximum k31 of 0.31, and the maximum Qm of 154 in perpendicular direction were obtained. 相似文献
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Thermal depolarization temperature, Td, of ferroelectric oxides Bi0.5Na0.5TiO3 (BNT), where dielectric and piezoelectric signals exhibit remarkable changes, is providing rich research contents but is not well understood yet. Herein, on the domain-scale, we give the direct and clear real-space images of thermal depolarization process on BNT-based complex oxides. As disclosed by the piezoresponse force microscopy (PFM), heating above Td breaks the poling-induced large-sized-oriented domains into smaller sized polar clusters with different orientations, leading to the thermal depolarization phenomenon. Although the poling-induced domain decays above Td, the broken domains exhibit a rather larger coherence length than that of the incipient labyrinth-like nano-domains. During the heating process, BNT possesses a structural transition from the long-range-correlated R3c (a−a−a− anti-phase tilting) to the short-range-correlated P4bm (a0a0c+ in-phase tilting) phase, which should be the fundamental driving force for the fluctuations of poling-induced large-sized-oriented domains. We expect these results will further promote the understanding about the origin of Td in BNT-based relaxor ferroelectrics, and provide an intuitive method for the characterization of the thermodynamic and kinetic process in this kind of materials. 相似文献