共查询到20条相似文献,搜索用时 15 毫秒
1.
Qiaoji Zheng Yongquan Guo Fengying Lei Xiaochun Wu Dunmin Lin 《Journal of Materials Science: Materials in Electronics》2014,25(6):2638-2648
Multiferroic ceramics of (0.70?x)BiFeO3–0.30BaTiO3–xBi(Zn0.5Ti0.5)O3 + 1 mol% MnO2 with perovskite structure were prepared by a conventional ceramic technique and the effects of Bi(Zn0.5Ti0.5)O3 doping and sintering temperature on the microstructure, multiferroic and piezoelectric properties of the ceramics were studied. All the ceramics possess a pure perovskite structure and no second phases can be detected. After the addition of a small amount of Bi(Zn0.5Ti0.5)O3 (x ≤ 0.05), the ferroelectric and piezoelectric properties of the ceramics are improved and the grain growth is promoted. However, excess Bi(Zn0.5Ti0.5)O3 (x ≥ 0.10) retards the grain growth, degrades the ferroelectricity and piezoelectricity, and induces two dielectric anomalies at high temperature. The ceramics can be well sintered at the very wide range of low sintering temperatures (880–980 °C) and exhibit good densification (relative density: 96.2–98.4 %) and strong electric insulation. The increase in the sintering temperature promotes the grain growth and improves the ferroelectricity of the ceramics. The ceramic with x = 0.05 sintered at 880–980 °C possesses improved ferroelectric and piezoelectric properties with remanent polarizations P r of 21.9–28.1 μm/cm2, piezoelectric constants d 33 of 125–139 pC/N and planar electromechanical coupling factors k p of 30.1–32.4 %, and high Curie temperatures T C of 523–565 °C. A weak ferromagnetism with remanent magnetizations M r of 0.0411–0.0422 emu/g and coercive fields H c of 1.70–1.99 kOe were observed in the ceramics with x = 0–0.025. 相似文献
2.
Zhenyong Cen Changrong Zhou Huabin Yang Qin Zhou Weizhou Li Changlai Yuan 《Journal of Materials Science: Materials in Electronics》2013,24(10):3952-3957
Mn modified BiFeO3–BaTiO3 (abbreviated as BFBT-Mnx%, x = 0.1, 0.3, 0.6, 0.9, 1.2) high-temperature lead-free ceramics were prepared by conventional oxide-mixed method and the effect of Mn doping on microstructure and electrical properties was investigated. The solid solutions show a single phase perovskite structure, and the content of Mn has a significant effect on the microstructure of ceramics. The addition of Mn can induce combinatory “hard” and “soft” piezoelectric characteristics due to aliovalent substitutions. In particular, x = 0.6 BFBT-Mnx% ceramic, with a Curie temperature, T c, of ~463 °C, shows optimum piezoelectric properties of d 33 = 131pC/N, k p = 0.298. The simultaneous existence of good piezoelectric properties and high T c makes these ceramics suitable for elevated temperature piezoelectric devices. 相似文献
3.
C. M. Lonkar S. Premkumar D. K. Kharat H. H. Kumar Sahab Prasad K. Balasubramanian 《Journal of Materials Science: Materials in Electronics》2013,24(6):1989-1993
This study investigates the behavior of Pb(1?z)Laz (NiSb)0.05 [(Zr0.52 Ti0.48)1?Z/4]0.95O3 (La-PNS-PZT) ceramics where z = 0.01–0.05 in response to cyclic electrical loading. Samples were fabricated by mixed oxide route and subjected to electrical stress by applying the electric load of 1,500 V, along the polar axis, with fatigue amplitudes of 20 V. Impedance and resonance frequency response was studied after every 106 cycles. Degradation in electromechanical coupling factor (kp), piezoelectric strain constant (d33) and dielectric constant ( $ K_{3}^{T} $ ) were also studied and correlated with structural properties. Results revealed that the La-PNS-PZT composition containing 3 mol% of lanthanum could be more suitable for actuator applications since it shows minimum degradation in properties after 1012 cycles of electric load. 相似文献
4.
Lingling Luo Na Jiang Fengying Lei Yongquan Guo Qiaoji Zheng Dunmin Lin 《Journal of Materials Science: Materials in Electronics》2014,25(4):1736-1744
(0.725 ? x)BiFeO3–0.275BaTiO3–xBi(Mg0.5Zr0.5)O3 + 1 mol% MnO2 lead-free ceramics (x = 0–0.08) were synthesized by a conventional solid state reaction method and the effects of Bi(Mg0.5Zr0.5)O3 on phase transition, piezoelectric and ferroelectric properties of the ceramics were investigated. After the addition of Bi(Mg0.5Zr0.5)O3, the crystal structure of the ceramics is transformed from rhombohedral to tetragonal phase and the morphotropic phase boundary (MPB) of rhombohedral and tetragonal phase is formed at x = 0.01. The grain size of the ceramics increases with x increasing from 0 to 0.02 and then decreases with x further increasing. The dielectric peak of the ceramics becomes diffusive with x increasing after the addition of Bi(Mg0.5Zr0.5)O3. The ceramics with x = 0–0.08 exhibit much better electric insulation with the resistivity of 1.0 × 109–5.0 × 109 Ω·cm than pure BiFeO3 ceramic with the resistivity of ~5 × 107 Ω·cm. Due to the formation of the MPB, the ceramics with x = 0–0.02 possess good densification with the relative densities ρ r of 94.9–96.3 %, strong piezoelectricity with the d 33 of 129–135 pC/N and very high Curie temperature with the T C of 559–610 °C. 相似文献
5.
6.
Hongwei Chen Chuanren Yang Chunlin Fu Jun Shi Jihua Zhang Wenjian Leng 《Journal of Materials Science: Materials in Electronics》2008,19(4):379-382
The crystalline structure and dielectric properties of BaZr
x
Ti1−x
O3 ceramics with x = 0.05, 0.10, 0.15, and 0.20 were investigated. As zirconium increased, the a-axis lattice constant gradually increased, however, the c-axis lattice constant and c/a ratio gradually decreased. When x = 0.20, the crystal structures of the BZT ceramics are very close to cubic, different from the tetragonal structure when
x < 0.20. The temperature dependence of the dielectric constant was studied and an enhanced diffuse phase transition behavior
is found to be caused by the increased Zr content. The decreases of coercive electric field and remanent polarization were
the result of increase of Zr/Ti ratio in BaZr
x
Ti1−x
O3. 相似文献
7.
Natthaphon Raengthon Harlan J. Brown-Shaklee Geoff L. Brennecka David P. Cann 《Journal of Materials Science》2013,48(5):2245-2250
In order to develop dielectric ceramics with temperature-stable permittivity characteristics, perovskite BaTiO3–Bi(Zn1/2Ti1/2)O3–NaNbO3 ceramic solid solutions were investigated with a particular focus on effects of BaTiO3 and NaNbO3 contents on the dielectric properties of ternary compounds. Keeping the ratios of the other two constituents constant, decreasing the BaTiO3 content leads to a broadening of the temperature-dependent permittivity maximum and a decrease in the overall permittivity. For compositions of constant BaTiO3 content, replacing Bi(Zn1/2Ti1/2)O3 with NaNbO3 shifts the temperature of the maximum permittivity to lower temperatures (e.g., to ?103 °C for a composition of 70BT–5BZT–25NN) while maintaining a broad permittivity peak with temperature, which for the 50BT–25BZT–25NN composition also satisfies the X9R standard. Thus, the investigation of BT–BZT–NN compounds resulted in promising dielectric properties with broad temperature ranges of high permittivity, which is of interest for advanced capacitor applications. 相似文献
8.
Yanqing Liu Yuhan Wu Dan Li Yongjun Zhang Jing Zhang Jinghai Yang 《Journal of Materials Science: Materials in Electronics》2013,24(6):1900-1904
The mixed spinel-perovskite multiferroic composites of xNiFe2O4-(1 ? x)BaTiO3 (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) have been prepared by sol–gel method. The structure and morphology of the composites were examined by means of X-ray diffraction and transmission electron microscope. High-resolution transmission electron microscope image indicates a clear view of ferrite and ferroelectric phase. Moreover, we observed a fine interface between the two phases, where the coupling effect of ferrite and ferroelectric phase happened. The composites show excellent ferromagnetic and ferroelectric properties. The saturation magnetization (Ms) reaches to 24.139 emu/g for x = 0.6 at room temperature, the magnetization is about 2.37 emu/g for x = 0.6 when the temperature decreases to 90 k, and the polarization reaches to 3.75 μC/cm2 for x = 0.1. Frequency dependent variations of dielectric constant and loss tangent for xNiFe2O4-(1 ? x)BaTiO3 were studied in detail. 相似文献
9.
Yongquan Guo Ping Xiao Lingling Luo Na Jiang Fengying Lei Qiaoji Zheng Dunmin Lin 《Journal of Materials Science: Materials in Electronics》2014,25(9):3753-3761
A new lead-free solid solution of (0.75 ? x)BiFeO3–0.25BaTiO3–xBi0.5(Na0.8K0.2)0.5TiO3 + 1 mol% MnO2 has been prepared by a conventional ceramic technique and the effects of Bi0.5(Na0.8K0.2)0.5TiO3 and sintering temperature on the structure, ferroelectric and piezoelectric properties of the material have been studied. The ceramics sintered at 960 °C for 2 h possess a pure perovskite structure and no second phases can be detected. After the addition of Bi0.5(Na0.8K0.2)0.5TiO3, a morphotropic phase boundary of rhombohedral and orthorhombic phases is formed at x = 0.01. The addition of a small amount of Bi0.5(Na0.8K0.2)0.5TiO3 can promote the grain growth, while excess Bi0.5(Na0.8K0.2)0.5TiO3 causes an inhibition of grain growth. Sintering temperature has an important influence on the structure and electrical properties of the ceramics. The sintering temperature of 960 °C is a critical temperature to obtain the ceramics with good piezoelectric properties. For the ceramic with x = 0.01 sintered at/above 960 °C located at the morphotropic phase boundary, large grains, good densification, high resistivity and enhanced electrical properties are obtained. 相似文献
10.
Lead-free high-temperature piezoceramics of MnO2-doped 0.69BiFeO3–0.02Bi(Mg1/2Ti1/2)O3–0.29BaTiO3 (BF69–BMT2–BT29) were prepared with solid state reaction method. Those ceramics were crystallized in a pure pseudocubic perovskite-structured phase. In contrast to high dielectric loss BF–BT binary solid solution ceramics, low dielectric loss ceramics were obtained here with combined strategies of refined electroceramic processing, Mn-doping and adding BMT third member. Ferroelectric and piezoelectric properties were systematically measured. Here, the 0.30 wt% MnO2-doped BF69–BMT2–BT29 ceramics sintered at 900 °C for 10 h showed a better combination of ferroelectric and piezoelectric properties than those BiFeO3–BaTiO3 piezoceramics. 相似文献
11.
Zong-Yang Shen Yue-Ming Li Wen-Qin Luo Zhu-Mei Wang Xing-Yong Gu Run-Hua Liao 《Journal of Materials Science: Materials in Electronics》2013,24(2):704-710
Polycrystalline Nd-doped SrTiO3 ceramics with the formula Nd x Sr1?x TiO3 (NSTO, x = 0, 0.024, 0.056, 0.104, 0.152, 0.200) were prepared by solid state reaction route. X-ray diffraction (XRD) analysis confirmed the formation of monophasic compounds and indicated the structure to be changed from cubic to tetragonal by increasing Nd doping concentrations. A remarkable decrease in grain size from ~30 μm for un-doped SrTiO3 ceramics to ~1 μm for Nd-doped SrTiO3 ceramics with x = 0.024 was observed by scanning electron microscopy. The grain size had a degree of increasing with further increasing Nd doping concentration and reached ~3 μm when the x value was 0.200. The dielectric properties of NSTO ceramics were measured at 1 kHz in ambient temperature. It revealed that the dielectric constant dramatically increases for the reason of Nd doping, leading to a maximum value of 19,800 for as-sintered sample with x = 0.104. The breakdown strength of all Nd-doped SrTiO3 samples was found to be higher than 10 kV/mm. The relationship between dielectric properties and the microstructure feature, as well as the defect structures correlated with the charge compensation induced by trivalent Nd3+ doping, was discussed tentatively. 相似文献
12.
The (1 − x)Bi(Zn1/2Ti1/2)O3–xPbZrO3 solid solution ceramics were prepared by using solid-state reaction method, and their ferroelectric properties were investigated.
It was found that the perovskite structure is stable for compositions with x ≥ 0.900. Within this composition range, the crystal structure of the solid solution preserves the orthorhombic symmetry of
PbZrO3 (PZ). The Curie point of the ceramics was found to decrease with increasing Bi(Zn1/2Ti1/2)O3 (BZT) content. The intermediate ferroelectric phase of PZ was stabilized by BZT addition and exists within a much wider temperature
range in the solid solution. 相似文献
13.
Zupei Yang Hongmei Ren Xiaolian Chao Pengfei Liang 《Materials Research Bulletin》2012,47(5):1273-1277
The phase structure, microstructure and dielectric properties of Na0.5Bi0.5?xLaxCu3Ti4O12 (NBLCTO) ceramics were investigated. La3+ substitution had a great influence on the phase structure and dielectric properties. The results showed that the pure phase could be more easily obtained when substituting La3+ for Bi3+. Under the same processing condition (970 °C for 7.5 h) and measuring condition (10 kHz around room temperature), NBLCTO ceramics with x = 0.10 possessed the highest permittivity (1.02 × 104) and lowest dielectric loss (0.022). The obtained NBLCTO ceramics with x = 0.10 also had good frequency stability and good temperature stability (?1.87% to +3.27%) from ?60 °C to 120 °C at both 1 and 10 kHz. Complex impedance results revealed that the grain resistance Rg was 7.18 Ω cm and the grain boundary resistance Rgb was 1.19 × 106 Ω cm. 相似文献
14.
In this study, a simple compound (1 ? x)(Bi0.5Na0.5)TiO3–xKNbO3 (x = 0 – 0.12) lead-free bulk ceramic was developed for high electric power pulse energy storage applications. The dielectric and ferroelectric properties of the ceramics were measured. The results illustrate that the energy storage density of the ceramics is enhanced by the addition of KNbO3. The influence of applied electric field, temperature, and fatigue on the energy storage properties of the ceramics was evaluated for the composition-optimized (Bi0.5Na0.5)TiO3–0.1KNbO3 ceramic. The results demonstrate that (Bi0.5Na0.5)TiO3–0.1KNbO3 ceramic is a promising lead-free material for high power pulse capacitor applications. The excellent energy storage properties of the (Bi0.5Na0.5)TiO3–0.1KNbO3 ceramics are ascribed to the reversible relaxor–ferroelectric phase transition induced by the electric field. 相似文献
15.
16.
Jiaojiao Ye Yunfei Liu Yinong Lu Jianxiang Ding Chengjian Ma Hao Qian Zhenglei Yu 《Journal of Materials Science: Materials in Electronics》2014,25(10):4632-4637
The energy-storage properties of SrTiO3-doped (15, 20, 25, and 30 mol%) 0.80Bi1/2Na1/2TiO3–0.20Bi1/2K1/2TiO3 lead-free antiferroelectric ceramics were investigated by two-step sintering method. The ceramics with higher SrTiO3 content had smaller grain sizes and a more homogeneous distribution. About 25 mol% SrTiO3 doping induced antiferroelectric properties, showing a typical double hysteresis loops, accompanied by a large energy density. The first sintering temperature of the ceramics had main impact on the relative density, and the high relative density possessed large external breakdown strength. The optimum electrical performances with a low remanent polarization (Pr = 1.9 μC/cm2), a low coercive field (Ec = 1.7 kV/cm) and a large energy density (W = 0.97 J/cm3) at 10 Hz were obtained at 1,190 °C for a SrTiO3 content of 25 mol%. 相似文献
17.
B. A. Rotenberg O. V. Rubinshtein S. V. Shtel’makh V. V. Pavshukov I. K. Boricheva 《Inorganic Materials》2014,50(8):854-860
We have studied the microstructure and dielectric properties of barium titanate-based ceramics containing niobium oxide and rare-earth (Nd, Sm, Gd, Dy, and Tm) oxide additions in a ratio needed for the formation of mixed perovskite solid solutions with the general formula Ba[Ti1 ? x (Ln1/2Nb1/2) x ]O3. It was found that, after sintering at 1100–1120°C with the use of a zinc oxide-based sintering aid and manganese carbonate additions, the ceramics had a core-shell structure in which the core of the grains consisted of barium titanate and the shell consisted of a barium titanate-based solid solution. The average grain size of the major phase in the ceramics was within 0.7 μm. The ceramics contained additional phases in the form of inclusions which occasionally exceeded 5 μm in size. Their composition was determined. The Nd-, Sm-, and Gd-containing materials were shown to have the greatest potential as a base for the development of new engineering materials of stable groups with high dielectric permittivity for multilayer capacitors with electrodes containing 70% Ag and 30% Pd. 相似文献
18.
Venkata Sreenivas Puli Dhiren K. Pradhan Douglas B. Chrisey M. Tomozawa G. L. Sharma J. F. Scott Ram S. Katiyar 《Journal of Materials Science》2013,48(5):2151-2157
We investigate the dielectric, ferroelectric, and energy density properties of Pb-free (1 ? x)BZT–xBCT ceramic capacitors at higher sintering temperature (1600 °C). A significant increase in the dielectric constant, with relatively low loss was observed for the investigated {Ba(Zr0.2Ti0.8)O3}(1?x ){(Ba0.7Ca0.3)TiO3} x (x = 0.10, 0.15, 0.20) ceramics; however, electric breakdown was low (~140, 170, 134 kV/cm), and of which room temperature (300 K) charging curve energy density values are largest ~0.88, 0.94, and 0.87 J/cm3 with maximum high dielectric constant values ~7800, 8400, and 5200, respectively. Bulk ceramic BZT–BCT materials have shown interesting energy densities with good energy storage efficiency (~72 %) at high sintering temperature; they might be one of the strong candidates for high energy density capacitor applications in an environmentally protective atmosphere. 相似文献
19.
Jinjin Zhang Ruzhong Zuo Yang Lv Yuanyuan Zhou Zhenxing Yue 《Journal of Materials Science: Materials in Electronics》2012,23(8):1449-1454
Microwave dielectric ceramics of Ba3Ti4?x(Mg1/3Nb2/3)xNb4O21 solid solutions (BTMNN-x, x?=?0–4) were prepared via the conventional solid-state reaction method. The X-ray powder diffraction analysis revealed that the BTMNN-x ceramics formed complete solid solutions with hexagonal structure. The dielectric constant (εr) and the temperature coefficient of the resonant frequency (τf) of BTMNN-x ceramics decreased with the increase of x, while the quality factor (Q?×?f) enhanced with increasing the substitution content. In addition, a small amount of BaCu(B2O5) (BCB) additive can effectively lower the sintering temperature of BTMNN ceramics. The 1.5?wt% BCB doped BTMNN-2 ceramics can be sintered at 950?°C and have good microwave dielectric properties of εr?=?50, Q?×?f?=?10,500?GHz and τf?=?18?ppm/°C, which makes it possible to be a promising candidate for mid-permittivity low temperature co-fired ceramic materials. 相似文献
20.
N. Y. Chan S. H. Choy D. Y. Wang Y. Wang J. Y. Dai H. L. W. Chan 《Journal of Materials Science: Materials in Electronics》2014,25(6):2589-2594
(Ba1?x,Srx)(Zr0.1,Ti0.9)O3 (BSZT) ceramics with x = 0, 0.05, 0.15, 0.25, 0.35 and 0.45 were prepared by conventional solid state reaction method. The structural characterization with X-ray diffraction and scanning electron microscopy indicate a monotonical drop in lattice constants and grain size with the increase of Sr concentration. Consequently, the Curie temperature and remnant polarization of the ceramics exhibit a strong compositional dependence. A linear relationship between the Curie temperature and Sr concentration is revealed. At x = 0.45, the BSZT ceramics show substantially high tunability of over 55 % under 20 kV/cm dc electric field with very low dielectric loss value of 0.0025 at room temperature, suggesting the BSZT ceramics could be a promising alternative to traditional (Ba,Sr) TiO3 ferroelectrics for developing high frequency tunable dielectric devices. 相似文献