共查询到18条相似文献,搜索用时 62 毫秒
1.
2.
3.
采用传统固相烧结法,制备了CaBi4Ti(1-x)NbxO1(5x=0.00-0.05,CBT-N)系铋层状结构无铅压电陶瓷。研究了Nb5+掺杂对CBT压电陶瓷压电与介电性能的影响。研究结果表明:添加Nb5+离子,改善了CBT陶瓷的烧结特性,提高了瓷体的致密度。Nb2O5的引入降低了CBT系列陶瓷的介质损耗,改善了陶瓷的压电与介电性能。当掺入量x=0.04(CaBi4Ti0.96Nb0.04O15)时制备的CBT基铋层状压电陶瓷具有优异的压电性能:d33=14pC/N,Qm=3086,εr=212,tanδ=0.0041,kt/kp=1.681。 相似文献
4.
采用固相法制备了(1-x)(Na0.5Bi0.5)TiO3-xBa0.5Sr0.5Nb2O6(0≤x≤1.0%)(简称(1-x)NBT-xBSN)无铅压电陶瓷,研究了不同BSN含量(x=0,0.1%,0.3%,0.5%,0.7%,1.0%,摩尔分数)样品的物相组成、显微结构及电性能.结果表明:所有样品均为纯钙钛矿结构,随掺杂量x的增加,陶瓷的相对密度pr、压电常数d33和机电耦合系数kp均先增大后降低,机械品质因子Qm和退极化温度Td则逐渐下降.该体系陶瓷具有弥散相变特征,弥散指数介于1.6~1.7.当x=0.5%时,陶瓷获得最佳性能:d33=92pC/N,kp=0.164,Qm=89,εr=650,tanδ=5.47%,pr=96.5%. 相似文献
5.
本文采用固相反应法制备了一系列LiBiO2掺杂0.94(Na0.8K0.16Li0.04)0.5Bi0.5TiO3 -0.06BaTiO3压电陶瓷,并采用SEM、XRD等分析方法对所得产物的结构和电性能进行分析.SEM观测表明:随LiBiO2掺杂量的增加,晶粒尺寸增加.XRD分析显示,LiBiO2掺杂会导致Na2O相析出.铁电测试表明随着LiBiO2掺杂量的增加,剩余极化强度和矫顽场单调下降,样品从铁电相向反铁电相转变.压电测试结果显示:随着LiBiO2掺杂量增加,d33单调下降.与单独Li、Bi掺杂提高电性能相反,LiBiO2掺杂对提高电性能无益. 相似文献
6.
采用固相法制备了(Ba0.85Ca0.15) (Ti0.90Zr0.06Sn0.04)O3-xmol%Fe2O3(简写为BCTZS-xFe)无铅压电陶瓷.研究了不同掺杂量对该陶瓷的显微结构、介电、铁电及压电性能的影响.结果表明,所有样品均具有单一的钙钛矿结构,少量掺杂能使晶粒长大,提高电性能.在x=0.025时,具有最佳的综合电性能,压电常数d33 =515 pC/N,机电耦合系数kp=48.2%,机械品质因数Qm =182,2Pr=18.2 μC/cm2,2Ec =4.3 kV/cm,介电常数εr=5175. 相似文献
7.
8.
Y2O3掺杂对(Bi0.5Na0.5)0.94Ba0.06TiO3无铅压电陶瓷性能的影响研究 总被引:1,自引:1,他引:0
采用传统固相反应法制备了Y2O3掺杂(Bi0.5Na0.5)0.94Ba0.06TiO3(简写为BNBT6)陶瓷[简称为BNBT6-x(wt%)Y2O3陶瓷].研究了Y2O3 (0.2wt%~0.8wt%)掺杂对BNBT6陶瓷的结构、介电、压电、铁电性能的影响.结果表明,所有Y2O3掺杂陶瓷样品均形成了单一的钙钛矿结构;陶瓷的介电、压电、铁电性能受Y2O3掺杂的影响较为显著:当掺杂0.4wt%Y2O3时,10 kHz频率下测得的室温εr达到1530,且tanδ较小,为0.050,d33达到152 pC/N,kp=0.27,Qm=134.掺杂0.2wt%的Y2O3时BNBT6陶瓷的d33为145 pC/N,kp增大到0.29,Qm达到173,tanδ为0.053;掺杂适量Y2O3的BNBT6陶瓷铁电性能也得到改善. 相似文献
9.
10.
11.
Shishuai Li Yongfeng Xia Dongxu Yao Hanqin Liang Yu-Ping Zeng 《International Journal of Applied Ceramic Technology》2023,20(1):465-474
Sintered reaction-bonded silicon nitride (SRBSN) with high thermal conductivity was obtained using (Y0.96Eu0.04)2O3 and MgO as sintering additives. Green compacts were nitrided at 1400°C for 4 h. Post-sintering was carried out at 1850 and 1900°C for 4 h, respectively. In reaction-bonded silicon nitride (RBSN) doped with Y2O3 and MgO, the β-Si3N4 content and nitridation degree were 51.1% and 93.8%, respectively. However, the β-Si3N4 content and nitridation degree were 72.6% and 96.7% in a nitrided compact doped with (Y0.96Eu0.04)2O3 and MgO. After post-sintering, the phase composition, microstructure, mechanical properties, and thermal conductivity were investigated. After sintering at 1900°C for 4 h, the thermal conductivity of SRBSN doped with (Y0.96Eu0.04)2O3 and MgO was increased by 16.5% compared to that of the samples doped with Y2O3 and MgO. The highest hardness of 1639 HV and the good flexural strength of 776.4 MPa were also achieved in the sample doped with 2-mol.% (Y0.96Eu0.04)2O3 and 5-mol.% MgO. 相似文献
12.
《Ceramics International》2023,49(4):6351-6360
Ferrite materials have the potential to become excellent absorbing materials due to their high magnetic loss and good impedance matching. However, the disadvantages of high density and lack of dielectric loss capability limit its application. Herein, we used the citric acid sol-gel method and the self-propagating combustion method to prepare neodymium-doped nickel-zinc ferrite (NZNF), then the target effect of Sn2+ and an improved electroless silver plating process was used to plate a layer composed of silver nanoparticles (Ag NPs) with strong dielectric loss on the NZNF, and a magnetic/dielectric composite material (NZNF@Ag) with a heterogeneous structure was prepared. The number and particle size of Ag NPs on the surface of NZNF can be precisely controlled, thereby greatly enhancing the dielectric loss capability with little impact on the magnetic loss. The huge difference in conductivity between conductors and semiconductors promotes the occurrence of polarization at the heterogeneous interface and significantly enhances the electromagnetic wave absorption ability of the composite material. In the 2–18 GHz frequency band, the best sample can obtain an effective bandwidth of 6.82 GHz when the matching thickness is 2.1 mm. Combining conductors with semiconductor materials to obtain significantly enhanced interfacial polarization provides a new idea for improving the performance of wave absorbing materials. 相似文献
13.
Irena Gruszka Antoni Kania Ewa Talik Magdalena Szubka Seweryn Miga Joanna Klimontko Jan Suchanicz 《Journal of the American Ceramic Society》2019,102(3):1296-1308
Ceramics of the perovskite multiferroics PbFe0.5Nb0.5O3 (PFN) and PbFe0.5Ta0.5O3 (PFT) were synthesized from new citrate polymeric precursors. X-ray tests pointed to trace amounts of the pyrochlore phase. SEM studies revealed the heterogeneous grain size distribution for PFN and the homogeneous one for PFT. Dielectric studies pointed to one diffuse T-C phase transition at 378 K for PFN and two diffuse M-T and T-C phase transitions, at 200 and 235 K, for PFT, respectively. X-ray photoelectron spectroscopy studies of PFN reveal that all ions exist in one valence state, however, with two chemical shifts for Pb2+. Two valence states for the majority of ions of PFT seem to be connected with a higher volume fraction of the amorphous grain-boundary phase. The electronic energy band gap for both compounds is approximately 2.8 eV. Two magnetic transitions, ie, from the paramagnetic to the antiferromagnetic phase and then to the spin-glass phase, were observed at 156 and 10 K for PFN, and at 145 and 15 K for PFT, respectively. 相似文献
14.
Zhuo Wang Haonan Chen Chun Wang Tian Wang Yujia Xiao Wenwen Nian 《Journal of the European Ceramic Society》2018,38(16):5402-5410
Pure phase of Ba0.94Bi0.04(Fe0.5Nb0.5)O3 (BBFN) nano-particles were obtained by chemical co-precipitation method. The core-shell structure of BBFN@SiO2 and BBFN@SiO2/Al2O3 particles and the target ceramics were successfully prepared by aqueous chemical coating approach. The microstructures and dielectric properties of BBFN@SiO2 and BBFN@SiO2/Al2O3 were studied. Both the BBFN@SiO2 and BBFN@SiO2/Al2O3 samples show significantly decreased dielectric loss and good frequency and temperature stability on relative permittivity. Compared to the rapid decline of relative permittivity of BBFN@SiO2, the synergistic effect of SiO2 and Al2O3 in BBFN@SiO2/Al2O3 ceramics made the relative permittivity of which remains a relatively high level with very low dielectric loss, making it more suitable in colossal permittivity applications. Based on the impedance analysis, the grain boundary effect and IBLC models play the important role for the improvement of dielectric properties of BBFN@SiO2/Al2O3 samples. 相似文献
16.
Hong-Qiang Wang Ye-Jing Dai Zhu-Rui Shen Xiao-Wen Zhang 《Journal of the European Ceramic Society》2012,32(8):1481-1484
(1 ? x)Bi0.5Na0.5TiO3–x(Na0.53K0.44Li0.04)(Nb0.88Sb0.08Ta0.04)O3 (BNT–xNKLNST) with x = 0–0.10 lead-free piezoelectric ceramics were prepared by a solid state method, and the structure and electrical properties were investigated in this study. It is found that a morphotropic phase boundary (MPB) of rhombohedral (R) and tetragonal (T) phase exists in the range of 0.03 ≤ x ≤ 0.05 and the structure changes to paraelectric phase when x > 0.07. The samples with x = 0.05 exhibit improved electrical properties owing to the formation of MPB, which are as follows: piezoelectric constant d33 = 120 pC/N, remnant polarization Pr = 39.4 μC/cm2 and coercive field Ec = 3.6 kV/mm. These results indicate that the enhanced piezoelectric properties for BNT can be achieved by forming the coexistence of R and T phase. 相似文献
17.
18.
采用溶胶-凝胶法制备A位掺Sr的LaxSr1-xCo0.5Cu0.5O3钙钛矿增强传统B位掺杂钙钛矿活化过一硫酸盐(PMS)的能力。本文选取效果最好的La0.7Sr0.3Co0.5Cu0.5O3型钙钛矿为研究对象,以偶氮染料AO7为目标污染物,考察了钙钛矿投加量、PMS浓度、pH和染料废水中常见Cl-对La0.7Sr0.3Co0.5Cu0.5O3/PMS体系降解AO7的影响,并测试了材料的重复利用性和矿化能力。结果表明,La0.7Sr0.3Co0.5Cu0.5O3/PMS降解AO7的速度随着材料投加量和PMS浓度的增加而加快,在中性条件下反应速度最快且矿化率良好。该体系主要活性物种之一为·OH,但Sr掺杂后钙钛矿的O空位增多使得1O2也参与到降解过程之中。 相似文献