共查询到17条相似文献,搜索用时 140 毫秒
1.
2.
研究了Er3 替代Bi3 对Bi2(Zn1/3Nb2/3)2O7系介质材料结构和性能的影响,并借助X射线、扫描电镜、Agilent4284测试仪对其相结构和介电性能进行分析.研究结果表明:经Er3 替代的BZN陶瓷样品烧结温度升高(从960℃升高到1000℃);随着Er3 替代量的增加,Bi2(Zn1/3Nb2/3)2O7系介质材料的晶粒尺寸、介电常数、介电损耗都有所变化;当替代量x=0.1时,介电性能最佳,介电常数为78.7165,介电损耗为0.00134. 相似文献
3.
用传统的固相法合成了Sm2O3掺杂的Bi2O3-ZnO-Nb2O5(BZN)基陶瓷(Bi1.5-xSmxZn0.5)(Zn0.5Nb1.5)O7(0≤x≤0.6,BSZN),通过XRD、AV2782阻抗分析仪等测试手段对其烧结行为、相结构及介电性能进行了系统研究.结果表明纯BZN陶瓷的结构为立方焦绿石单相;当Sm2O3掺杂量较少(0<x≤0.5)时,样品的相结构仍然保持立方焦绿石单相;随着Sm2O3掺杂量的进一步增加(x≥0.6),样品出现其它相.同时,试样的介电性能随结构的变化而呈现有规律的变化. 相似文献
4.
5.
为获得温度稳定型高频高介材料,通过复相介电组成调控原理,将正温度系数型焦绿石相(Bi1.5Zn0.5)(Zr1.5Nb0.5)O7(BZZN)与负温度系数型(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7(BZN)混合构成BZN-BZZN复相材料.研究了该系列陶瓷的物相组成、晶体结构及介电性能随两相组成的变化规律.晶体结构精修获得了复相结构中两相的晶格常数、A-O'键长、B--O键长、O—B—O键角的变化.复相陶瓷的介电性能可通过两相比例有规律地调制,随着BZZN含量增多,(1-x)BZN-xBZZN介电常数εr略有下降,介电常数温度系数逐渐由负值向正值变化.当x=0.7时,获得高介电常数、零温度系数陶瓷材料:εr=123.2,tanδ=7×10-4,αε=5×10-6/℃. 相似文献
6.
采用固相反应制备(Bi2-xWx)(Zn1/3Nb2/3)2O7陶瓷。研究W6+替代Bi3+对铋锌铌基陶瓷烧结特性、相结构及介电性能的影响。结果表明:掺杂BZN烧结温度略有降低;样品相结构保持单一的单斜焦绿石相,其相结构向高角方向移动;随着W6+替代量的增加,介质材料的介电常数、介电损耗及温度系数都有所变化;当x=0.2时,样品的性能最优,εr=95.39、tanδ=3.89×10-3,αc=228.7×10-6。 相似文献
7.
8.
利用X射线衍射分析、SEM对Bi2O3-ZnO-B2O3系统低熔点玻璃的烧结性能、玻璃的结晶、烧结后玻璃试样的结构进行了研究.研究结果表明:随着ZnO含量的增加,玻璃试样的烧结收缩率有所增加,烧结变得相对容易,玻璃颗粒液相出现所需要的温度-有所降低.Bi2O3-ZnO-B2O3系统低熔点玻璃粉末的烧结是在有粘性液相参与下的烧结过程,使得玻璃试样的致密化更加有效,效率更高.B组试样中都析出了a-Bi2O3晶相.当温度继续升高时,试样的烧结收缩出现了"滞缓"的现象,试样中有大量的液相出现,试样在表面张力的作用下出现了流散. 相似文献
9.
通过X射线衍射、扫描电镜、精密阻抗分析仪等对A位Y3 取代的Bi(1.5-x)YxZnNb1.5O7介质陶瓷样品的结构和介电性能进行了研究.结果表明:当Y3 取代量较少时(x≤0.2),样品保持立方焦绿石结构;当Y3 取代较多时(x≥0.4),样品出现第二相.随着取代量的增加,样品的致密化温度升高,表观密度减小,晶粒尺寸减小,介电常数减小,介电损耗增加.Y3 取代后(x≤0.8),样品的温度系数得到优化,且具有良好的高频稳定性.低温的介电弛豫现象随着Y3 取代的增加发生有规律的变化,表现为介电常数下降,介电常数峰宽化和平坦. 相似文献
10.
11.
Longwen Wu Xiaohui Wang Zhengbo Shen Longtu Li 《Journal of the American Ceramic Society》2017,100(1):265-275
The (1?x)BaTiO3–xBi(Zn2/3Nb1/3)O3 (x = 0.01–0.30) ceramics were synthesized by solid‐state reactions. The solubility limit was determined to be x = 0.20. A systematic structural transition from a tetragonal phase (x ≤ 0.034), to a mixture of tetragonal and rhombohedral phases (0.038 ≤ x ≤ 0.20), and finally to a pseudocubic phase (x ≥ 0.22) at room temperature was identified. Dielectric measurement revealed a ferroelectric (x ≤ 0.04) to relaxor (x ≥ 0.06) transition with permittivity peak broadening and flattening, which was further verified by Raman spectroscopy and differential scanning calorimetry (DSC). Activation energies obtained from the Vogel–Fulcher model displayed an increasing trend from ~0.03 eV for x ~ 0.05, to unusually high values (>0.20 eV) for the compositions with x ≥ 0.15. With the increase in Bi(Zn2/3Nb1/3)O3 content, the polarization hysteresis demonstrated a tendency from high nonlinearity to sublinearity coupled with the reduction in remnant polarization and coervice field. The deconvolution of the irreversible/reversible polarization contribution was enabled by first‐order reversal curve distributions, which indicates that the decreasing polarization nonlinearity with the increase in Bi(Zn2/3Nb1/3)O3 concentration could be related with the change from the ferroelectric domain and domain wall contributions to the weakly coupled relaxor behaviors. 相似文献
12.
Y3+取代对(Bi1.5Zn0.5)(Nb0.5Ti1.5)O7陶瓷显微结构与介电性能的影响 总被引:1,自引:0,他引:1
研究了Y3 取代的(Bi1.5Zn0.5)(Nb0.5Ti0.5)O7(BZNT)基陶瓷(Bi1.5-xYx Zn0.5)(Nb0.5Ti1.5)O7(0≤x≤1.5,BYZNT)的显微结构和介电性能。采用传统的固相反应法制备陶瓷样品,XRD分析样品的相结构。结果表明:BZNT陶瓷的相结构中主相为立方焦绿石相;在整个取代范围内,BYZNT陶瓷的结构仍然保持主相为立方焦绿石的相结构。同时,随着Y3 取代的增加,晶胞体积减小,介电性能随结构的变化而呈现有规律的变化。其介电性能为:εr≈73-180,tanδ≈1.6%-0.4%,αε≈(-583-89)× 10-6/℃(1MHz)。 相似文献
13.
Nitish Kumar Eric A. Patterson Till Frömling David P. Cann 《Journal of the American Ceramic Society》2016,99(9):3047-3054
Polycrystalline BaTiO3–Bi(Zn1/2Ti1/2)O3 (BT–BZT) ceramics have superior dielectric properties for high‐temperature and high‐energy density applications as compared to the existing materials. While it has been shown that the addition of BZT to BT leads to an improvement in resistivity by two orders of magnitude, in this study impedance spectroscopy is used to demonstrate a novel change in conduction mechanism. While nominally undoped BT exhibits extrinsic‐like p‐type conduction, it is reported that BT–BZT ceramics exhibit intrinsic n‐type conduction using atmosphere‐dependent conductivity measurements. Annealing studies and Seebeck measurements were performed and confirmed this result. For BT, resistivity values were higher for samples annealed in nitrogen as compared to oxygen, whereas the opposite responses were observed for BZT‐containing solid solutions. This suggests a fundamental change in the defect equilibrium conditions upon the addition of BZT to the solid solution that lowered the carrier concentration and changed the sign of the majority charge carrier. This is then also linked to the observed improvement in resistivity in BT–BZT ceramics as compared to undoped BT. 相似文献
14.
V. A. Isupov O. V. Rubinstein B. A. Rotenberg N. V. Emel'Yanova 《Ferroelectrics Letters Section》2005,32(1):23-29
Solid solutions (1-x)PbMg1/3Nb2/3O3 + xPbCd1/3Nb2/3O3 with x = 0-0.30 are investigated with purpose to work out a capacitor ceramics with good dielectric properties and low sintering temperature. It is found that the perovskite phase forms at sintering near to 980°C and begins to decompose at higher temperatures. When x grows from 0 to 0.30, the Curie temperature linearly grows from -10°C to +25°C, the dielectric permittivity εm in the Curie point TC decreases from 18000 to 6800 and the phase transition becomes more diffused. The dielectric permittivity at room temperature is rather high and the temperature stability is improved. The system is of interest, because it can serve as a base for working out some ceramic materials for capacitors with low sintering temperature, which needs of no special atmosphere at burning. 相似文献
15.
Longwen Wu Xiaohui Wang Zhengbo Shen Bingcheng Luo Longtu Li 《Journal of the American Ceramic Society》2017,100(2):511-514
The (1?x)BaTiO3?xBi(Zn2/3Nb1/3)O3 (x=0.10‐0.25) ceramics were fabricated via solid‐state reactions. Temperature‐dependent polarization measurement reveals that with the temperature lowering, the remnant polarization increases till a maximum value before it decreases, showing a reentrant phenomenon. Absence of apparent switching current peaks in the current density as a function of electric field should indicate the lack of a ferroelectric transition, which is further verified by the consistent macroscopic phase structure from the Raman spectra. An anomalous peak in the full width at half maximum of a deconvoluted mode at ~515 cm?1 suggests the entering of a more disordered state of dipolar dynamics, which may be originated from the competition between the freezing of polar nanoregions and the random interacting fields. 相似文献
16.