共查询到20条相似文献,搜索用时 31 毫秒
1.
Jun Wang Changrong Zhou Qingning Li Weidong Zeng Jiwen Xu Guohua Chen Changlai Yuan Guanghui Rao 《Journal of Materials Science》2018,53(12):8844-8854
Lead-free ceramics (1???x)Bi0.5Na0.5TiO3–xSr0.85Bi0.1TiO3 (BNT–xSBT, x?=?0.4, 0.5, 0.6 and 0.7) were prepared by a solid-state reaction process. Coexistence of ferroelectric relaxation at low temperature and Maxwell–Wagner dielectric relaxation at high temperature was revealed for the first time in this system. Meanwhile, hysteresis-free P–E loops combined with a very high piezoelectric strain coefficient (d33) of 1658 pC/N concurrently with large electrostrictive coefficient Q?=?0.287 m4C?2 were achieved. The ferroelectric relaxor behavior and large electrostrictive strain might be linked to easy reorientation and reversal of ergodic PNRs and the combined effect of Bi off-center position and lone pair electrons. 相似文献
2.
Muhammad Qadeer Awan Javed Ahmad Lasse Norén Teng Lu Yun Liu 《Journal of Materials Science: Materials in Electronics》2018,29(9):7142-7151
The effect of BiErO3 (BE) as a doping material on the structural, dielectric and ferroelectric properties of (KNa)NbO3 ceramics was explored in this research. Co-existence of two phase regions was confirmed in the composition range at x?=?0.5% and x?=?1.0%. The addition of BE content led to a decrease of the grain size and the ceramics became denser. Bulk P–E hysteresis loops were obtained with a maximum polarization of P max = 30.56 µC/cm2 and a remnant polarization of P r = 25.10 µC/cm2, along with a coercive field of E c ~ 11.26 kV/cm. The results revealed that a field strain value of ~?0.26 for x?=?0.5% of BE substitution was attained. This presents outstanding piezoelectric and dielectric properties. 相似文献
3.
E. D. Politova A. V. Mosunov D. A. Strebkov N. V. Golubko G. M. Kaleva B. A. Loginov A. B. Loginov S. Yu. Stefanovich 《Inorganic Materials》2018,54(7):744-748
We have studied the phase formation, microstructure, and dielectric and ferroelectric properties of (Na0.5–xBi0.5)TiO3 and (Na0.5Bi0.5 + x)TiO3 nonstoichiometric ceramics with Na/Bi < 1 and x = 0–0.1. The grain size of the ceramics has been shown to decrease with increasing x. The temperature dependences of dielectric permittivity for the samples studied have anomalies near ~400 K and peaks at ~600 K, corresponding to ferroelectric phase transitions. The phase transitions near 400 K demonstrate relaxor behavior, indicative of the presence of polar regions in a nonpolar matrix, as supported by laser second harmonic generation measurements. In addition, the (Na0.5Bi0.5 + x)TiO3 samples with x > 0.05 have anomalies near 900 K, confirming the presence of Bi4Ti3O12 as an impurity phase, which is accompanied by an increase in the spontaneous polarization of these samples. 相似文献
4.
M. N. Palatnikov N. V. Sidorov V. V. Efremov O. G. Gromov Yu. V. Radyush 《Inorganic Materials》2008,44(11):1240-1243
The dielectric permittivity of Li x Na1 ? x NbO3 ferroelectric solid solutions prepared at high pressures has been measured as a function of temperature and frequency, and their structural properties have been studied. The results demonstrate that ceramics samples of the Li x Na1 ? x NbO3 (x = 0.17, 0.25) ferroelectric perovskite solid solutions exhibit superionic conduction at relatively low temperatures (T ≥ 400 K). In the temperature range of superionic conduction, we observe significant dielectric dispersion and anomalies in permittivity, corresponding to structural transformations of the high-pressure solid solutions. 相似文献
5.
Lei Guo Jian-Min Yan Yuan-Yuan Zhang Zhi-Xue Xu Meng Xu Lai-Hui Luo Fei-Fei Wang Yu-Kuai Liu Shuai Dong Ren-Kui Zheng 《Journal of Materials Science: Materials in Electronics》2018,29(11):9007-9015
A series of In3+-doped Ba0.85Ca0.15TiO3:0.75%Er3+/xIn3+ (BCT:Er/xIn) lead-free piezoelectric ceramics with excellent upconversion luminescence were synthesized by the solid state reaction method. The effects of In3+ content on the crystal structure, ferroelectric, dielectric, piezoelectric, and upconversion luminescence properties were systematically studied. Under 980 nm excitation, a giant enhancement of the green emission (550 nm) by 10 times is achieved upon 2.5% mol In3+ doping, which is rarely observed in rare-earth ions-doped perovskite ferroelectric materials. The ultraviolet-visible-near infrared absorption measurements show that the In3+ doping may improve the dissolution of Er3+ ions and modify the isolate-/clustered-Er3+ ratio for x?≤?2.5%, resulting in the enhancement of the absorption cross-section, thereby contributing to the enhancement of green luminescence. Unfortunately, the In3+ doping suppresses the ferroelectric and piezoelectric properties of the BCT:Er/xIn ceramics. This problem can be resolved by adding a small amount (1 mol%) of Yb3+ to the BCT:Er/xIn ceramics to restore their good ferroelectric and piezoelectric properties. Such In3+ and rare-earth ions co-doped ceramics with greatly enhanced upconversion luminescence and good ferroelectricity and piezoelectricity may have potential applications in electro-optical devices. 相似文献
6.
Perovskite type (Ba0.85Ca0.15?2x Bi2x )(Zr0.1Ti0.9?x Cu x )O3 lead-free ceramics were prepared via a conventional solid-state reaction method. The phase structure, dielectric, ferroelectric properties and complex impedance were investigated in detail. XRD and dielectric measurements determined that single orthorhombic phase displayed in (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 at room temperature. With the introduction of Bi2O3/CuO, the phase structure exhibited the mixture of orthorhombic and tetragonal phases, and then turned to single tetragonal phase. In contrast to the sharp dielectric transition of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 ceramics, a broad dielectric peak coupled with a slight decrease in Curie temperature was observed in (Ba0.85Ca0.15?2x Bi2x )(Zr0.1Ti0.9?x Cu x )O3 ceramics with increasing x. The observed diffuse phase transition behavior was further confirmed by a couple of measurements with polarization loops and polarization current density curves. The structural and the composition fluctuations induced by ions doping should be responsible for the diffuse phase transition behavior. Furthermore, physical mechanisms of the conduction and relaxation processes were revealed by using impedance spectroscopy analyses. It was concluded that the conduction and relaxation processes were thermally activated, which was closely linked with the singly and doubly ionized oxygen vacancies. 相似文献
7.
Lyndsey M. Denis Julia Glaum Mark Hoffman John E. Daniels Ryan J. Hooper Goknur Tutuncu Jennifer S. Forrester Jacob L. Jones 《Journal of Materials Science》2018,53(3):1672-1679
The effect of mechanical stress on the direct piezoelectric properties of pre-poled (1 ? x)(Na0.5Bi0.5)TiO3–xBaTiO3 (NBT–xBT) in the range 4% ≤ x ≤ 13% was studied in situ using a mechanical load frame. Prior to mechanical loading, compositions near the morphotropic phase boundary (MPB, x = 6–7% BT) exhibited enhanced ferroelectric and piezoelectric properties compared to compositions further from the MPB. Specifically, the lowest ferroelectric coercive field and highest piezoelectric coefficient within this composition range occur at x = 7% BT. During mechanical compression, the MPB compositions exhibited the lowest depoling stress. The results demonstrate that, while favorable piezoelectric and ferroelectric properties can be obtained at compositions near the MPB, these compositions are also the most susceptible to the effects of mechanical depoling. Ferroelastic domain wall motion is suggested as the primary factor that may be responsible for these behaviors. 相似文献
8.
Pallabi Gogoi L. R. Singh D. Pamu 《Journal of Materials Science: Materials in Electronics》2017,28(16):11712-11721
In the present study the effect of Zn substitution on densification, microstructure, microwave and broad band dielectric properties of MgTiO3 ceramics were investigated. The (Mg1?x Zn x )TiO3 (x?=?0.01–0.07) ceramics have been prepared by the conventional solid-state reaction method. The sintering conditions were optimized to obtain the best dielectric properties with maximum relative densities. The microwave dielectric properties are heavily influenced by the amount of x concentration. The optimum dielectric properties of ε r ~ 17.34, Q?×?f o ~ 274 THz, τ f ~ -40.3 ppm/oC is obtained for (Mg0.95Zn0.05)TiO3 ceramics sintered at 1275?°C. The broad band dielectric properties of (Mg0.95Zn0.05)TiO3 ceramics were measured in the frequency range of 1–100 MHz, and temperature range of 133–483 K. Interestingly, the broad band dielectric properties show relaxation behaviour with frequency. The higher temperature dielectric spectrum of (Mg0.95Zn0.05)TiO3 (MZT) ceramics displayed a distinct dispersion, which is shifting towards a lower frequency side. The observed dielectric relaxation behavior is analyzed using Cole–Cole plot. Furthermore, voltage dependent capacitance behavior at different frequencies is studied for the MZT sample, and it’s interesting to note that the capacitance is stable with the variation in voltage. The electrical conductivity study is carried out as a function of frequency and temperature for MZT sample and the activation energy is calculated by using Arrhenius equation, which is found to be 0.07 eV at 10 MHz. The obtained dielectric response of MZT ceramics are suitable for dielectric resonator and type-1 RF capacitor applications. 相似文献
9.
(Ba0.67Sr0.33)1?3x/2Y x Ti1?y/2Mn y O3 [BST(Mn + Y), x = 0.006, y = 0.005] ceramics were fabricated by using citrate–nitrate combustion derived powder. Microstructure and dielectric properties of the BST(Mn + Y) ceramic samples were investigated within the sintering temperature ranged from 1220 to 1300 °C. Sintering temperature has a great influence on the microstructure and electrical properties of the ceramic samples. The dielectric properties, ferroelectric properties, and tunability are enhanced by optimizing sintering temperature. The relatively high tunability of 40 % (1.5 kV/mm DC field, 10 kHz) was obtained, and relatively low dielectric loss, <0.0052 (at 10 kHz, 20 °C) was acquired for BST(Mn + Y) samples sintered at 1275 °C for 3 h. Both the low dielectric loss and enhanced tunable properties of BST(Mn + Y) are useful for tunable devices application. 相似文献
10.
Huiling Guo Yang Li Yong Zhang Huajun Sun Xiaofang Liu 《Journal of Materials Science: Materials in Electronics》2018,29(22):19063-19069
The (1???2x)NBT–xKBT–xBT ternary piezoelectric system has been extensively studied in recent years. However, its electrical performance is far inferior to lead-based counterparts, and could not meet the requirements for practical applications. In this contribution, the 0.92NBT–0.04KBT–0.04BT (abbreviated as NKBT4) ceramics were prepared by traditional solid-state method. The effects of doped cobalt content on the structure and electrical performance of NKBT4 ceramics were studied systematically. The content of Co2O3 affects the average grain size, maximum dielectric constant, piezoelectric properties and the ferroelectric responses of the ceramics. It was found that the introduction of cobalt did not affect the phase structure of the ceramics, but is beneficial for the improvement of the dielectric and piezoelectric properties. When x?=?0.2, the piezoelectric coefficient (d33) is around 130 pC/N, which is greatly improved compared to pure NKBT4 ceramics. Besides, a relatively high dielectric constant (εr?=?1150) was obtained at the same composition. This work paves a new way for the further development of high performance lead-free piezoelectric ceramics. 相似文献
11.
Fangfang Zeng Qibin Liu Yuanyu Wang Shiqiang Peng An Xue Enpei Cai 《Journal of Materials Science: Materials in Electronics》2018,29(22):18978-18988
In the work, the preparation technology of SrTiO3 is carefully investigated. The (Ba0.85Ca0.15)(Zr0.08Ti0.9Sn0.02)O3-SrTiO3 piezoelectric ceramics are successfully synthesized by conventional solid-state reaction method, and the microstructure, ferroelectric and dielectric properties are studied in detail. The excellent ferroelectric properties are obtained when x?=?20 wt.% (Pr and Ec are 11.67 µC/cm2 and 2.06 kV/mm, respectively). In addition, the Curie temperature is 114 °C at x?=?5 wt.%. The dielectric permittivity εr, dielectric loss tanδ and relaxor behavior are investigated in the work. In particular, two dielectric loss peaks, Model A and Model B, are systematically discussed. 相似文献
12.
Jitkasem Mayamae Wanwilai Vittayakorn Rangson Muanghlua Somsak Woramongkolchai Naratip Vittayakorn 《Journal of Materials Science》2017,52(12):6928-6936
Design of the polymorphic phase composition in the (0.975-y)BaTiO3–0.025SrTiO3–yBaSnO3; BT-ST-yBSn ternary system was based on the ferroelectric phase diagram. The dense ceramic of BT-ST-yBSn, with y = 0.00, 0.02, 0.04, 0.06, 0.08 and 0.10 compositions, was fabricated successfully via the solid-state reaction method. The effect of Sn substitution on the ferroelectric phase transition and piezoelectric properties was explored in order to achieve high-performance piezoelectric properties. All of the ceramics exhibited pure perovskite structures. Orthorhombic to tetragonal phase transition was evidenced clearly as a function of Sn content. The orthorhombic to tetragonal phase transition shifted close to ambient temperature by increasing the Sn content. The coexistent tetragonal and orthorhombic phases were exhibited at the composition, y = 0.04, and showed outstanding dielectric and piezoelectric properties, maximum relative permittivity (ε r max) of 11500 and piezoelectric coefficient (d 33) of 450 pC/N. An outstanding reversible strain of about 0.12%, with a normalized piezoelectric coefficient (S max /E max) of 1280 pm/V at a low electric field (10 kV/cm), was observed clearly at the composition of the coexistent phase. The BT-ST-BSn ceramics are the most promising candidate for lead-free piezoelectric materials. 相似文献
13.
Pan Ruan Peng Liu Bao-chun Guo Feng Li Zhi-fen Fu 《Journal of Materials Science: Materials in Electronics》2016,27(5):4201-4205
The ZnO–Nb2O5–xTiO2 (1 ≤ x ≤ 2) ceramics were fabricated by reaction-sintering process, and the effects of TiO2 content and sintering temperature on the crystal structure and microwave dielectric properties of the ceramics were investigated. The XRD patterns of the ceramics showed that ZnTiNb2O8 single phase was formed as x ≤ 1.6 and second phase Zn0.17Nb0.33Ti0.5O2 appeared at x ≥ 1.8. With the increase of TiO2 content and sintering temperature, the amount of the second phase Zn0.17Nb0.33Ti0.5O2 increased, resulting in the increase of dielectric constant, decrease of Q × f value, and the temperature coefficient of resonant frequency (τ f ) shifted to a positive value. The optimum microwave dielectric properties were obtained for ZnO–Nb2O5–2TiO2 ceramics sintered at 1075 °C for 5 h: ε r = 45.3, Q × f = 23,500 GHz, τ f = +4.5 ppm/°C. 相似文献
14.
Xing Liu Baihui Liu Feng Li Peng Li Jiwei Zhai Bo Shen 《Journal of Materials Science》2018,53(1):309-322
Lead-free Bi0.495(Na0.8K0.2)0.495Sr0.01Ti1?x (Fe0.5Me0.5) x O3 ceramics with x = 0?0.03/0.04 mol (Me = Nb, Sb and Ta, abbreviated as FN0.5–FN4, FS0.5–FS3 and FT0.5–FT3, respectively) were fabricated by a conventional solid-state reaction method. The effects of B-site complex ions content on relaxor phase evolution and electromechanical properties were systematically investigated. Results showed that the modification of FN, FS and FT complex ions can significantly reinforce the B-site compositional disorder, effectively destroy the long-range ferroelectric order and tune the ferroelectric–relaxor transition point (T FR) to around room temperature. The relatively high strain performances (dynamic \(d_{{33}}^{*}\) values) of 567, 550 and 600 pm/V were obtained in FN2, FS1.5 and FT2 critical compositions, respectively. The large strain responses are closely associated with the reversible relaxor–ferroelectric phase transformation. Furthermore, the electrostrain of FT2 sample presents a temperature-insensitive characteristic with the variation less than 10% up to 120 °C. These findings indicate that the B-site complex ions modified NBT-based ceramics can be considered as promising candidates for lead-free electromechanical actuator applications. 相似文献
15.
Yu. V. Radyush N. M. Olekhnovich I. I. Moroz A. V. Pushkarev 《Inorganic Materials》2007,43(4):418-424
(1 ? x)PbMg1/3Nb2/3O3 · xPbZrO3 (1 ? x)PMN · xPZ) solid solutions have been synthesized at a pressure of 5 GPa and temperatures from 1300 to 1700 K, and their structural and dielectric properties have been studied. The composition dependences of the average unit-cell parameter and dielectric permittivity for the solid solutions indicate that the PMN-PZ system has a morphotropic phase boundary near x = 0.65. The solid solutions have a cubic structure for x < 0.65, a rhombohedral structure in the range 0.65 < x < 0.9, and an orthorhombic structure (similar to that of PbZrO3) for x > 0.9. The temperature and frequency dependences of dielectric permittivity suggest that the (1 ? x)PMN · xPZ samples with x < 0.65 consist of two ferroelectric phases: a relaxor with antipolar dipole order and a normal ferroelectric with a diffuse phase transition. The effect of annealing temperature on the ferroelectric state of the samples with x < 0.65 is examined. In the composition range 0.65 < x < 0.9, the samples have normal ferroelectric properties, independent of annealing temperature. 相似文献
16.
Dielectric and electrical properties of relaxor ferroelectric 0.9PMN-0.1PT ceramics prepared by a sol-gel method were investigated as a function of PbZrO3 atmosphere powders. The proper amount of atmosphere powders led to better properties of dielectric constant, polarization, and strain by preventing PbO volatilization from ceramics. Excessive amount of atmosphere powder, however, resulted in aging characteristics such as decreases in dielectric constant and loss exhibiting saddle-shaped dielectric constant and loss vs. temperature curves. A propeller-shaped P-E hysteresis curve indicating aging characteristics was also observed when an excessive amount of atmosphere powder was used during sintering. The aging of ceramics caused by absorption of PbO into the ceramics resulted in decreased polarization and strain. These aging characteristics associated with defects by excessive PbO absorption could not be reversed even though the aged ceramics underwent a heat-treatment above the dielectric maximum temperature. 相似文献
17.
Querui Hu Yiping Wang Lei Wu Jiang Yin Lang Chen Guoliang Yuan Ying Yang 《Journal of Materials Science: Materials in Electronics》2018,29(21):18036-18044
Piezoelectric ceramics xLiNbO3–yBiScO3–(1?x?y)PbTiO3 (LN–BS–PT, 0.00?≤?x?≤?0.10, 0.30?≤?y?≤?0.36) were synthesized and their phase diagram and morphotropic phase boundary between rhombohedral and tetragonal phases have been confirmed. The optimal properties were found at the composition of 0.03LN–0.36BS–0.61PT with piezoelectric coefficient d33* value of 702 pm/V, d33 of 551 pC/N, planar electromechanical coupling factor kp of 0.51, remnant polarization Pr of 46.5 µC/cm2, Curie temperature Tc of 337 °C, and a large strain of 0.351% at an electric field of 50 kV/cm and frequency of 2 Hz with a low strain hysteresis of 5.9%. The Curie temperature of the ternary system presents a linear relationship with LiNbO3 and BiScO3 contents. The optimization of these electric properties was probably ascribed to the enhancement in domain walls and the improving mobility of domain switching due to LiNbO3 doping. 相似文献
18.
Sheng Liu Shuoqing Yan Heng Luo Lingling Yao Zhaowen Hu Shengxiang Huang Lianwen Deng 《Journal of Materials Science》2018,53(2):1014-1023
Multiferroic properties of La-modified four-layered perovskite Bi5?x La x Fe0.5Co0.5Ti3O15 (0 ≤ x ≤ 1) ceramics were investigated, by analyzing the magnetodielectric effect, magneto-polarization response and magnetoelectric conversion. X-ray diffraction indicated the formation of pure Aurivillius ceramics, and Raman spectroscopy revealed the Bi ions displacement and the crystal structure variation. The enhancement of ferromagnetic and ferroelectric properties was observed in Bi5?x La x Fe0.5Co0.5Ti3O15 after La modification. The evidence for enhanced ME coupling was determined by magnetic field-induced marked variations in the dielectric constant and polarization. A maximum ME coefficient of 1.15 mV/cm·Oe was achieved in Bi4.25La0.75Fe0.5Co0.5Ti3O15 ceramic, which provides the possible promise for novel magnetoelectric device application. 相似文献
19.
Xiao Yan Xiuli Chen Xiaoxia Li Gaofeng Liu Hailin Zhang Huanfu Zhou 《Journal of Materials Science: Materials in Electronics》2018,29(6):4538-4546
(1 ? x)(K0.5Na0.5)NbO3–xBi(Mg0.75Mo0.25)O3 [(1 ? x)KNN–xBMM] (x?=?0.005, 0.01, 0.02) ceramics were prepared via a solid-state reaction method. X-ray diffraction patterns (XRD) and Raman spectrum showed that a solid solution was formed between the BMM and KNN, which improved the electrical properties of KNN. With increasing the BMM content, the grain firstly increased and then decreased. When x?=?0.01, the ceramics exhibited the optimized microstructure, indicating that there exits an optimal doping component. Temperature dependence of relative permittivity also increases firstly and then decreases. The relative permittivity (εr) of ~?1418 in stabilization zone, εmax?~?4861 at the Curie temperature T C ~ 394 °C, good temperature stability ?ε/ε123 °C?≤?±?15% from 123 °C to 348 °C, and the dielectric loss tanδ?≤?0.036 from 109 to 348 °C were obtained for 0.99KNN-0.01BMM ceramics. Conductivity behavior of the (1 ? x)KNN–xBMM was investigated as a function of temperature from 420 to 520 °C and frequency from 40 to 106 Hz, showing that the basic mechanisms of conduction and relaxation processes were thermally activated, and oxygen vacancies were the possible ionic charge transport carriers at higher temperatures. 相似文献
20.
Gaofeng Liu Xiuli Chen Guisheng Huang Dandan Ma Huanfu Zhou 《Journal of Materials Science: Materials in Electronics》2017,28(5):3931-3935
In this paper, (1 ? x)(K0.5Na0.5)NbO3–xBi(Mg0.75W0.25)O3 (x = 0–0.015) lead-free dielectric ceramics were investigated. XRD analysis certified that the Bi(Mg0.75W0.25)O3 has diffused into (K0.5Na0.5)NbO3 to fabricate a new solid solution. The addition of Bi(Mg0.75W0.25)O3 depressed the orthorhombic–tetragonal phase transition temperature from 210 to 176 °C and tetragonal–pseudocubic phase transition temperature (Curie point) from 419 to 400 °C. As x = 0.005, the ceramics exhibited high relative permittivity (ε ~ 1325), low dielectric loss (tan δ < 2.9%) tan δ stability (Δε/ε168°C ≤ ±15%) in the temperature range of 168 ~ 369 °C. Especially, the ceramics also showed optimized piezoelectric constant (d 33 = 122 pC N?1) and remnant polarization (Pr = 32.57 μC cm–2). These results indicated that the BMW added ceramics have potential applications in ferroelectric and thermal stability devices. 相似文献