共查询到20条相似文献,搜索用时 31 毫秒
1.
Enhanced pyroelectric properties in (Bi0.5Na0.5)TiO3–BiAlO3–NaNbO3 ternary system lead‐free ceramics 下载免费PDF全文
Ping Peng Hengchang Nie Zhen Liu Fei Cao Genshui Wang Xianlin Dong 《Journal of the American Ceramic Society》2018,101(9):4044-4052
High pyroelectric performance and good thermal stability of pyroelectric materials are desirable for the application of infrared thermal detectors. In this work, enhanced pyroelectric properties were achieved in a new ternary (1?x)(0.98(Bi0.5Na0.5)(Ti0.995Mn0.005)O3–0.02BiAlO3)–xNaNbO3 (BNT–BA–xNN) lead‐free ceramics. The effect of NN addition on the microstructure, phase transition, ferroelectric, and pyroelectric properties of BNT–BA–xNN ceramics were investigated. It was found that the average grain size decreased as x increased to 0.03, whereas increased with further NN addition. The pyroelectric coefficient p at room temperature (RT) was significantly increased from 3.87 × 10?8Ccm?2K?1 at x = 0 to 8.45 × 10?8Ccm?2K?1 at x = 0.03. The figures of merit (FOMs), Fi, Fv and Fd, were also enhanced with addition of NN. Because of high p (7.48 × 10?8Ccm?2K?1) as well as relatively low dielectric permittivity (~370) and low dielectric loss (~0.011), the optimal FOMs at RT were obtained at x = 0.02 with Fi = 2.66 × 10?10 m/V, Fv = 8.07 × 10?2 m2/C, and Fd = 4.22 × 10?5 Pa?1/2, which are superior to other reported lead‐free ceramics. Furthermore, the compositions with x ≤ 0.03 exhibited excellent temperature stability in a wide temperature range from 20 to 80°C because of high depolarization temperature (≥110°C). Those results unveil the potential of BNT–BA–xNN ceramics for infrared detector applications. 相似文献
2.
Ping Peng Hengchang Nie Chan Zheng Genshui Wang Xianlin Dong Chunrong Yang 《Journal of the American Ceramic Society》2021,104(7):3344-3353
(Bi0.5Na0.5)TiO3 (BNT)-based ferroelectric ceramics have drawn extensive attention because of their excellent electrical properties and interesting depolarization behavior. However, the poor thermal stability of electrical properties limits their practical application. In this work, the effect of sintering temperature (Ts) on the depolarization behavior of BNT-based ceramics was systematically investigated. It is found that the depolarization temperature Td determined from pyroelectric measurement tends to decrease with increasing Ts, which indicates that lower Ts defers the ferroelectric-relaxor (FE-RE) phase transition. However, for the samples sintered at higher Ts (such as 1180°C), although the Td is reduced, the thermal stability is better compared with the sample sintered at lower Ts (1100°C) because the diffuse behavior of the FE-RE phase transition is suppressed. According to these results, we propose that the thermal stability of electrical properties for BNT-based ceramics is not only related to high Td, but also to the diffuse degree of phase transition. 相似文献
3.
Improved Pyroelectric Properties of CaBi4Ti4O15 Ferroelectrics Ceramics by Nb/Mn Co‐Doping for Pyrosensors 下载免费PDF全文
Yanxue Tang Zong‐yang Shen Shujun Zhang Thomas R. Shrout 《Journal of the American Ceramic Society》2016,99(4):1294-1298
The pyroelectric properties of Nb(Mn)‐doped and Nb/Mn co‐doped CaBi4Ti4O15 (CBT) bismuth layer‐structured ferroelectric ceramics were investigated. It was found that Nb/Mn co‐doping resulted in stronger enhancement of pyroelectric properties than that of single Nb or Mn doping. The mechanism of doping effect was explained by the distortion of the [BO6] octahedra induced by the doped Nb and Mn cations occupying the B‐site of the pseudoperovskite structure. A large pyroelectric coefficient of 84.4 μC/m2K was obtained at room temperature for Nb/Mn co‐doped CBT (CBTN‐Mn) ceramics, higher than that of pure, Nb or Mn‐doped counterparts, being on the order of 35.9, 58.2, 44.0 μC/m2K, respectively. The enhanced pyroelectric coefficient together with reduced dielectric constant (99) and dielectric loss (0.002) led to greater improvement of figures of merit (FOMs), including FOMs for voltage responsivity (Fv ~ 3.95 × 10?2 m2/C) and detectivity (Fd ~ 2.44 × 10?5 Pa?1/2), in CBTN‐Mn ceramics. Furthermore, the temperature variations of Fv and Fd were found to be 24% and 68%, respectively, over a broad temperature range from room temperature to 350°C, making CBTN‐Mn ceramics potential candidate for high‐temperature pyroelectric devices. 相似文献
4.
Wangfeng Bai Yanlong Bian Jigong Hao Bo Shen Jiwei Zhai 《Journal of the American Ceramic Society》2013,96(1):246-252
The (1?x) (Bi0.5Na0.5)TiO3?xBa(Al0.5Ta0.5)O3((1?x)BNT‐xBAT) lead‐free piezoceramics was fabricated using a conventional solid‐state reaction method. The temperature and composition‐dependent strain behavior, dielectric, ferroelectric (FE), piezoelectric, and pyroelectric properties have been systematically investigated to develop lead‐free piezoelectric materials with large strain response for actuator application. As the BAT content increased, the FE order is disrupted resulting in a degradation of the remanent polarization, coercive field, and the depolarization temperature (Td). A large strain of 0.36% with normalized strain d33* = 448pm/V was obtained for the optimum composition x = 0.045 at room temperature. The bipolar and unipolar strains for the compositions x = 0.035 and x = 0.04 reach almost identical maximum values when the temperature is in the vicinity of their respective depolarization temperature (Td). The Raman‐spectra analysis, macroscopic properties, thermal depolarization results, and temperature‐dependent relationships of both polarization and strain demonstrated that the origin of the large strain response for this investigated system is attributed to a field‐induced relaxor to FE phase transformation. 相似文献
5.
Electric Field‐Induced Phase Transition Behaviors,Thermal Depolarization,and Enhanced Pyroelectric Properties of (Pb0.97La0.02)(ZrxSn0.89−xTi0.11)O3 Ceramics 下载免费PDF全文
Fangping Zhuo Qiang Li Jinghan Gao Yujie Wang Qingfeng Yan Yiling Zhang Xiangcheng Chu 《Journal of the American Ceramic Society》2016,99(6):2047-2054
(Pb0.97La0.02)(ZrxSn0.89?xTi0.11)O3 (x = 0.60, 0.62, 0.64, 0.66, 0.68, 0.70, 0.72, and 0.74) ceramics with the compositions in tetragonal antiferroelectric (AFE) region, near the morphotropic phase boundary, were prepared by using the conventional solid‐state reaction process. Their electric field‐induced phase transitional behaviors, composition‐ and temperature‐dependent dielectric, depolarization, and pyroelectric properties were investigated systematically. The AFE to ferroelectric phase switching field EA‐F decreased with increasing x, while depolarization temperature Td increased with a linear relationship of Td = 842x‐483. Enhanced pyroelectric coefficient with a value of 12.1 μC/cm2/K was obtained at 88°C for the ceramics with x = 0.68, which was four times larger than the reported values. Composition‐dependent pyroelectric response over 24°C–140°C was realized by changing x from 0.60 to 0.74. The results also suggested that the enhanced pyroelectric response near Td was accompanied by a release of large Pr, caused by an induced ferroelectric to AFE phase transition. 相似文献
6.
Bin Hu Zhao Pan Ming Dai Fei‐Fei Guo Huanpo Ning Zheng‐Bin Gu Jun Chen Ming‐Hui Lu Shan‐Tao Zhang Bin Yang Wenwu Cao 《Journal of the American Ceramic Society》2014,97(12):3877-3882
Er‐doped 0.94Bi0.5Na0.5TiO3‐0.06BaTiO3 (BNT‐6BT: xEr, x is the molar ratio of Er3+ doping) lead‐free piezoceramics with x = 0–0.02 were prepared and their multifunctional properties have been comprehensively investigated. Our results show that Er‐doping has significant effects on morphology of grain, photoluminescence, dielectric, and ferroelectric properties of the ceramics. At room temperature, the green (550 nm) and red (670 nm) emissions are enhanced by Er‐doping, reaching the strongest emission intensity when x = 0.0075. The complex and composition‐dependent effects of electric poling on photoluminescence also have been measured. As for electrical properties, on the one hand, Er‐doping tends to flatten the dielectric constant‐temperature (εr‐T) curves, leading to temperature‐insensitive dielectric constant in a wide temperature range (50°C–300°C). On the other hand, Er‐doping significantly decreases the ferroelectric‐relaxor transition temperature (TF–R) and depolarization temperature (Td), with the TF–R decreasing from 76°C to 42°C for x = 0–0.02. As a result, significant composition‐dependent electrical features were found in ferroelectric and piezoelectric properties at room temperature. In general, piezoelectric and ferroelectric properties tend to become weaker, as confirmed by the composition‐dependent piezoelectric coefficient (d33), planar coupling factor (kp), and the shape of polarization‐electric field (P–E), current‐electric field (J–E), bipolar/unipolar strain‐electric field (S–E) curves. Furthermore, to understand the relationship between the TF–R/Td and the electrical properties, the composition of x = 0.0075 has been intensively studied. Our results indicate that the BNT‐6BT: xEr with appropriate Er‐doping may be a promising multifunctional material with integrated photoluminescence and electrical properties for practical applications. 相似文献
7.
Enhanced ferroelectric properties and thermal stability of Mn‐doped 0.96(Bi0.5 Na0.5)TiO3‐0.04BiAlO3 ceramics 下载免费PDF全文
Ping Peng Hengchang Nie Zhen Liu Weijun Ren Fei Cao Genshui Wang Xianlin Dong 《Journal of the American Ceramic Society》2017,100(3):1030-1036
(Bi0.5Na0.5)TiO3–BiAlO3 lead‐free materials exhibit excellent ferroelectric properties, but its depolarization temperature is relatively low which is the major obstacle limiting the material's practical application. In this study, the effects of Manganese (Mn) modification on the microstructure, ferroelectric properties and depolarization behavior of 0.96(Bi0.5Na0.5)(Ti1?xMnx)O3–0.04BiAlO3 ceramics were investigated. It was found that the average grain size was enlarged and ferroelectric properties were enhanced with small Mn addition, meanwhile the tangent loss decreased. The remnant polarization (Pr) of the samples reached an optimal value (~41 μC/cm2) as Mn content increased up to 0.7 mol%, whereas further addition resulted in the decrease in Pr. Moreover, appropriate Mn addition (x=0.7%) can improve the depolarization temperature from 140°C to 161°C determined from thermally stimulated depolarization currents measurement. 相似文献
8.
Improved thermal stability of the piezoelectric properties of (Li,Ag)‐co‐modified (K,Na) NbO3‐based ceramics prepared by spark plasma sintering 下载免费PDF全文
High‐performance lead‐free piezoelectric ceramics 0.94(K0.45Na0.55)1?xLix(Nb0.85Ta0.15)O3–0.06AgNbO3 (KNNLTAg‐x) were successfully prepared by spark plasma sintering technique. The doping effect of Li on the structural and electrical properties of KNNLTAg‐x (x=0, 0.02, 0.04, 0.06, 0.08 and 0.10) ceramics was studied. The lattice structure, ferroelectric and piezoelectric properties of the KNLNTAg‐x ceramics are highly dependent on the Li doping level. In particular, the Li dopant has a great impact on both Curie temperature Tc and orthorhombic‐tetragonal transition temperature TO‐T. The 4% Li‐doped sample exhibited relatively high TO‐T of 95°C, leading to a stable dynamic piezoelectric coefficient (d33*) of 220‐240 pm/V in a broad temperature range from 25°C to 105°C. Additionally, the 2% Li‐doped sample shows a high d33* of 320 pm/V at 135°C, suggesting its great potential for high‐temperature applications. 相似文献
9.
Xiao‐Yu Geng Ji Zhang Rui‐Xue Wang Xian‐Zhu Deng Lei Sun Zheng‐Bin Gu Shan‐Tao Zhang 《Journal of the American Ceramic Society》2017,100(12):5659-5667
Bi0.5Na0.5TiO3‐based incipient ferroelectrics with pseudocubic structure generally show weak ferro‐/piezoelectricity but giant field‐induced strains. It is difficult to artificially and smoothly improve the electrical property based on conventional chemical doping or substituting without changing the crystal structure and suppressing the strain. Here, by introducing the semiconductor ZnO into the lead‐free incipient ferroelectric ((Bi0.5(Na0.84K0.16)0.5)0.96Sr0.04)(Ti0.975Nb0.025)O3 (BNT–2.5Nb) to form 0‐3 type composites (BNT–2.5Nb:xZnO), we experimentally illustrate that the resistance and ferro‐/piezoelectric properties can be enhanced significantly with an unchanged crystal structure and only slightly suppressed strains. For example, the remanent polarization and piezoelectric coefficient increase from 4.6 μC/cm2 and 8 pC/N for x=0 to 9.0 μC/cm2 and 31 pC/N for x=0.3. At the same time, the total strain only decreases from 0.140% for x=0 to 0.108% for x=0.3, whereas the negative strain increases from ?0.003% for x=0 to ?0.010% for x=0.3. And the thermal stability of d33 is enhanced. The corresponding mechanism is attributed to that ZnO can form a local field, preventing the depolarization of field induced macroscopic ferroelectric domains. Our results not only provide a feasible way to tune electrical properties of BNT‐based incipient ferroelectrics, but also may stimulate further work on artificially structured high‐performance ferroelectrics. 相似文献
10.
Weixian Luo Meixia Wu Yifeng Han Xiang Zhou Laijun Liu Qiuwei He Pengrong Ren Haiming Yang Hui Yang Qiao Wang Zihao Chen Xihui Liang Zhifeng Chen 《Journal of the American Ceramic Society》2023,106(8):4723-4731
Dielectric ceramics with both excellent energy storage and optical transmittance have attracted much attention in recent years. However, the transparent Pb-free energy-storage ceramics were rare reported. In this work, we prepared transparent relaxor ferroelectric ceramics (1 − x)Bi0.5Na0.5TiO3–xNaNbO3 (BNT–xNN) by conventional solid-state reaction method. We find the NN-doping can enhance the polarization and breakdown strength of BNT by suppressing the grain growth and restrained the reduction of Ti4+ to Ti3+. As a result, a high recoverable energy-storage density of 5.14 J/cm3 and its energy efficiency of 79.65% are achieved in BNT–0.5NN ceramic at 286 kV/cm. Furthermore, NN-doping can promote the densification to improve the optical transmittance of BNT, rising from ∼26% (x = 0.2) to ∼32% (x = 0.5) in the visible light region. These characteristics demonstrate the potential application of BNT–xNN as transparent energy-storage dielectric ceramics. 相似文献
11.
Investigation of MnO2‐doped (Ba,Ca)TiO3 lead‐free ceramics for high power piezoelectric applications 下载免费PDF全文
x% mol MnO2‐doped Ba0.925Ca0.075TiO3 ceramics (abbreviated as BCT‐Mnx, x=0‐1.5) were synthesized by conventional solid‐state reaction method. The effects of MnO2 addition and (Ba+Ca)/Ti mole ratio (A/B ratio) on the microstructure and electrical properties of the ceramics were investigated. The internal bias filed Ei was determined from the asymmetrical polarization hysteresis loops and found to increase with the doping concentration of MnO2. High mechanical quality factors (Qm>1200) and low dielectric loss (tanδ<0.5%) were found in the BCT‐Mn0.75 and BCT‐Mn1.0 ceramics with Ei>3 kV/cm, meanwhile, the piezoelectric and electromechanical properties were found to decrease compared with the pure BCT, exhibiting a typical characteristic of “hard” behavior. Of particular interest is that the microstructure of BCT‐Mn0.75 ceramics could be controlled by changing the A/B ratio, where enhanced piezoelectric coefficient d33 on the order of 190 pC/N was obtained in the BCT‐Mn0.75 ceramics with A/B=1.01 due to its fine‐grained microstructure, with yet high Qm, being on the order of 1000. The high d33 and Qm in MnO2‐doped BCT ceramics make it a promising candidate for high power piezoelectric applications. 相似文献
12.
Enhanced piezoelectric properties and electrocaloric effect in novel lead‐free (Bi0.5K0.5)TiO3‐La(Mg0.5Ti0.5)O3 ceramics 下载免费PDF全文
Feng Li Biao Lu Jiwei Zhai Bo Shen Huarong Zeng Shengguo Lu Giuseppe Viola Haixue Yan 《Journal of the American Ceramic Society》2018,101(12):5503-5513
The crystal structure, electromechanical properties, and electrocaloric effect (ECE) in novel lead‐free (Bi0.5K0.5)TiO3‐La(Mg0.5Ti0.5)O3 ceramics were investigated. A morphotropic phase boundary (MPB) between the tetragonal and pseudocubic phase was found at x = 0.01‐0.02. In addition, the relaxor properties were enhanced with increasing the La(Mg0.5Ti0.5)O3 content. In situ high‐temperature X‐ray diffraction patterns and Raman spectra were characterized to elucidate the phase transition behavior. The enhanced ECE (ΔT = 1.19 K) and piezoelectric coefficient (d33 = 103 pC/N) were obtained for x = 0.01 at room temperature. Meanwhile, the temperature stability of the ECE was considered to be related to the high depolarization temperature and relaxor characteristics of the Bi0.5K0.5TiO3‐based ceramics. The above results suggest that the piezoelectric and ECE properties can be simultaneously enhanced by establishing an MPB. These results also demonstrate the great potential of the studied systems for solid‐state cooling applications and piezoelectric‐based devices. 相似文献
13.
Juan Liu Xiao Qiang Liu Xiang Ming Chen 《Journal of the American Ceramic Society》2017,100(9):4045-4057
Multiferroic ceramics were prepared and characterized in (1?x)BiFeO3–x(0.5CaTiO3–0.5SmFeO3) system by a standard solid‐state reaction process. The structure evolution was investigated by X‐ray diffraction and Raman spectrum analyses. The refinement results confirmed the different phase assemblages with varying amounts of polar rhombohedral R3c and nonpolar orthorhombic Pbnm as a function of the substitution content. In the compositions range of 0.2≤x≤0.5, polar R3c and nonpolar Pbnm coexisted, which was referred to polar‐to‐nonpolar morphotropic phase boundary (MPB). According to the dielectric and DSC analysis results, the ceramics with x≤0.2 changed to diffused ferroelectric, and the ferroelectric properties were enhanced significantly. Two dielectric relaxations were detected in the temperature range of 200‐300 K and 500‐700 K, respectively. The high‐temperature dielectric relaxation was attributed to the grain‐boundary effects. While the low temperature dielectric relaxation obtained in the samples with x=0.3‐0.5 was related to the charge transfer between Fe2+ and Fe3+. The magnetic hysteresis loops measured at different temperature indicated the enhanced magnetic properties in the present ceramics, which could be attributed to the suppressed cycloidal spin magnetic structure by Ti ions. In addition, the rare‐earth Sm spin moments might also affect the magnetic properties at relatively lower temperature. 相似文献
14.
Julia Glaum Hugh Simons Matias Acosta Mark Hoffman 《Journal of the American Ceramic Society》2013,96(9):2881-2886
This article details the influence of zirconium doping on the piezoelectric properties and relaxor characteristics of 94(Bi1/2Na1/2)TiO3–6Ba(ZrxTi1?x)O3 (BNT–6BZT) bulk ceramics. Neutron diffraction measurements of BNT–6BZT doped with 0%–15% Zr revealed an electric‐field‐induced transition of the average crystal structure from pseudo‐cubic to rhombohedral/tetragonal symmetries across the entire compositional range. The addition of Zr up to 10% stabilizes this transition, resulting in saturated polarization hysteresis loops with a maximum polarization of 40 μC/cm2 at 5.5 kV/mm, while corresponding strain hysteresis measurements yield a maximum strain of 0.3%. With further Zr addition, the ferroelectric order is progressively destabilized and typical relaxor characteristics such as double peaks in the current density loops are observed. In the strain hysteresis, this destabilization leads to an increase of the maximum strain by 0.05%. These changes to the physical behavior caused by Zr addition are consistent with a reduction of the transition temperature TF‐R, above which the field‐induced transformation from the relaxor to ferroelectric state becomes reversible. 相似文献
15.
J. Anthoniappen C.‐H. Lin C. S. Tu P.‐Y. Chen C.‐S. Chen S.‐J. Chiu H.‐Y. Lee S.‐F. Wang C.‐M. Hung 《Journal of the American Ceramic Society》2014,97(6):1890-1894
Structure and piezoelectric coefficient (d33) of lead‐free 7.5% mole BaTiO3‐doped (Bi0.5Na0.5) TiO3 (BNT‐7.5%BT) polycrystalline piezoceramics have been characterized systematically as a function of poling electric (E) field. Dielectric permittivity and loss were also measured as functions of frequency and temperature. The piezoelectric coefficient d33 after poling at E = 35 kV/cm can reach d33~186 pC/N, which is the highest value reported among (1?x) BNT–xBT compositions. A prior poling E field can reduce rhomobherdal lattice distortion, and enhance tetragonal phase and polarization ordering, that contribute significantly to the rapid raise of d33 and lower depolarizing temperature (Td). The reduced dielectric permittivity for the poled sample is attributed to ordered state and the pinning of field‐induced nanodomain walls by the presence of oxygen vacancies. 相似文献
16.
《Journal of the European Ceramic Society》2020,40(15):5392-5401
(Bi1/2Na1/2)TiO3-based materials have received much attention due to large electro-strain and high piezoelectric constant (d33), but the tough issue is that the existence of inherent depolarization temperature (Td) limits the temperature stability and application temperature range. Previously, reports about the formation of BNT/oxide (i.e., ZnO, Al2O3) composites thought that Td can be deferred to a higher temperature and then thermal depolarization improves. However, the deferred Td of BNT/oxide composites is limited, accompanied by a low d33. Here, we design the {[Bi0.5(Na0.8K0.2)0.5]1-xPbx}TiO3 ceramics, leading to a big shift of Td from 77 ℃ to 390 ℃. Large d33 (140 pC/N) and high Td (∼263 ℃) can be simultaneously achieved for the sample with Pb=0.05, and Td could be further deferred higher (390 ℃) for Pb=0.20. The off-centre displacement of Pb induced by Pb-O hybridization in the PbO12 polyhedron and ferroelectric order stabilized by the addition of Pb can provide the driving force to strengthen the ferroelectric order, and then promote the thermal stability. 相似文献
17.
Giant electromechanical strain response in lead‐free SrTiO3‐doped (Bi0.5Na0.5TiO3–BaTiO3)–LiNbO3 piezoelectric ceramics 下载免费PDF全文
Lei Wu Bo Shen Querui Hu Jing Chen Yiping Wang Yidong Xia Jiang Yin Zhiguo Liu 《Journal of the American Ceramic Society》2017,100(10):4670-4679
Lead‐free 0.985[(0.94?x)Bi0.5Na0.5TiO3–0.06BaTiO3–xSrTiO3]–0.015LiNbO3 [(BNT–BT–xST)–LN, x=0‐0.05] piezoelectric ceramics were prepared using a conventional solid‐state reaction method. It was found that the long‐range ferroelectric order in the unmodified (BNT–BT)–LN ceramic was disrupted and transformed into the ergodic relaxor phase with the ST substitution, which was well demonstrated by the dramatic decrease in remnant polarization (Pr), coercive field (Ec), negative strain (Sneg) and piezoelectric coefficient (d33). However, the degradation of the ferroelectric and piezoelectric properties was accompanied by a significant increase in the usable strain response. The critical composition (BNT–BT–0.03ST)–LN exhibited a maximum unipolar strain of ~0.44% and corresponding normalized strain, Smax/Emax of ~880 pm/V under a moderate field of 50 kV/cm at room temperature. This giant strain was associated with the coexistence of the ferroelectric and ergodic relaxor phases, which should be mainly attributed to the reversible electric‐field‐induced transition between the ergodic relaxor and ferroelectric phases. Furthermore, the large field‐induced strain showed relatively good temperature stability; the Smax/Emax was as high as ~490 pm/V even at 120°C. These findings indicated that the (BNT–BT–xST)–LN system would be a suitable environmental‐friendly candidate for actuator applications. 相似文献
18.
High permittivity (1−x)Bi1/2Na1/2TiO3‐xPbMg1/3Nb2/3O3 ceramics for high‐temperature‐stable capacitors 下载免费PDF全文
Fanting Hu Xuefeng Chen Ping Peng Fei Cao Xianlin Dong Genshui Wang 《Journal of the American Ceramic Society》2018,101(10):4434-4440
(1?x)Bi1/2Na1/2TiO3‐xPbMg1/3Nb2/3O3[(1?x)BNT‐xPMN] ceramics have been fabricated via a conventional solid‐state method for compositions x ≤ 0.3. The microstructure, phase structure, ferroelectric, and dielectric properties of ceramics were systematically studied as high‐temperature capacitor materials. XRD pattern certified perovskite phase with no secondary phase in all compositions. As PMN concentration increased, the phase of (1?x)BNT‐xPMN ceramics transformed from ferroelectric to relaxor gradually at room temperature, with prominent enhancement of dielectric temperature stability. For the composition x = 0.2, the temperature coefficient of capacitance (TCC) was <15% in a wide temperature range from 56 to 350°C with high relative permittivity (>3300) and low dielectric loss (<0.02) at 150°C, which indicated promising future for (1?x)BNT‐xPMN system as high‐temperature stable capacitor materials. 相似文献
19.
Modulation of electrostriction and strain response in bismuth sodium titanate‐based ceramics 下载免费PDF全文
Yuxing Zhang Jie Yin Chunlin Zhao Bo Wu Jiagang Wu 《Journal of the American Ceramic Society》2018,101(7):3005-3014
The electrostriction and strain response of lead‐free Bi0.5Na0.5TiO3–BaTiO3 piezoceramics with La and Nb [(Bi0.47Na0.47Ba0.06)1?xLaxTi1?yNbyO3] were modified by optimizing the depolarization temperature. The influences of La and Nb on their phase structure and electrical properties were systematically investigated. All the ceramics exhibited a pseudocubic phase, which is independent of the addition of La and Nb. The strain values increased gradually with the addition of La, and a high strain of ~0.5% (80 kV/cm) was attained without any remnant strain when the compositions had a value of x = 0.015. Instead, the piezoelectric constant d33 dropped down ~20 pC/N due to the shift of the Td (or Tf?r) to room temperature. Interestingly, by establishing the relationship between Td and strain values, it should be feasible to optimize the strain property of Bi0.5Na0.5TiO3 (BNT)‐based ceramics by regulating Td to ambient temperature. In addition, a very high electrostriction coefficient Q33 of ~0.0758 m4 C?2 can be found under high temperatures of 125 and 150°C. We believe that the strain and electrostriction behavior of BNT‐based ceramics can be well modified by the modulation of depolarization temperature. 相似文献
20.
Gyung Hyun Ryu Ali Hussain Myang Hwan Lee Rizwan Ahmed Malik Tae-Kwon Song Won-Jeong Kim Myong-Ho Kim 《Journal of the European Ceramic Society》2018,38(13):4414-4421
In this article, structure, dielectric, ferroelectric and piezoelectric properties of Bi rich Bi1.05(Zn0.5Ti0.5)O3-modified BiFeO3-BaTiO3 (BF-BT-xBZT) ceramics were investigated experimentally. Crystal structure, phase purity and microstructure were examined through X-ray diffractometry and scanning electron microscopy, respectively. The crystallographic results show the formation of single-phase solid solutions for all compositions except x?=?10?mol%. The BF-BT modification through BZT instigates variation in grain size, enhancement in Curie temperature (TC) and field induced polarization and strain response. Large field induced strain of ~0.24% at low driving field along with a small hysteresis of ~38% was observed for 2?mol% BZT modified BF-BT ceramics. These investigated results signpost the potentiality of BF-BT-xBZT ceramics in high temperature piezoelectric device applications. 相似文献