scholarly journals Piezoelectric properties of cerium-doped bismuth barium titanate intergrowth ceramics

2021 ◽  
Vol 15 (2) ◽  
pp. 120-127
Author(s):  
Xianwen Wang ◽  
Xiangping Jiang ◽  
Xin Nie ◽  
Xiaokun Huang ◽  
Chao Chen ◽  
...  

Structure and electrical properties of cerium doped bismuth barium titanate Ba1-xCexBi8Ti7O27 (x = 0, 0.05, 0.1, 0.15, 0,2 and 0.3) ceramics were investigated. X-ray diffraction revealed that the ceramic samples are of single stable phase. The ceramics possess typical plate-like structure with obvious decrease in the grain size with increasing Ce-doping amount. The dielectric properties of the materials show relaxor behaviour. Furthermore, the total resistance increase was observed with Ce-doping and the doped samples show good insulation properties. The Ba0.9Ce0.1Bi8Ti7O27 ceramics has the best piezoelectric performance (d33 = 20.6 pC/N) in contrast to that of the undoped BaBi8Ti7O27 ceramics (d33 = 6.7 pC/N), which is substantially enhanced piezoelectric performance of the material by more than three times.

2014 ◽  
Vol 1061-1062 ◽  
pp. 83-86
Author(s):  
Hong Wu ◽  
De Yi Zheng

In this paper, the effects of different sintering temperature on the microstructure and piezoelectric properties of Pb(Nb2/3Zn1/3)0.03(Zr52Ti48)0.97O3(PNZZT) ceramic samples were investigated. The Pb(Nb2/3Zn1/3)0.03(Zr52Ti48)0.97O3 ceramics materials was prepared by a conventional mixed oxide method. In the period of the experiment, the relationship between crystallographic phase and microstructure were analyzed by X-ray diffraction(XRD) and scanning electron microscopy(SEM) respectively. The XRD patterns shows that all of the ceramic samples are with a tetragonal perovskite structure. Along with sintering temperature increased and the x is 0.03, the grain size gradually become big. Through this experiment, it has been found that when the x is 0.03 and sintered at 1130°C for 2 h, the grains grow well, the grain-boundary intersection of the sample combined well and the porosity of the ceramics decreased, an excellent comprehensive electrical properties of the Pb(Nb2/3Zn1/3)0.03(Zr52Ti48)0.97O3 samples can be obtained. Its best electrical properties are as follows: dielectric constant (ε) is 1105, dielectric loss(tg) is 0.017, electromechanical coupling coefficient (Kp) is 0.287, piezoelectric constant(d33) is 150PC/N


2019 ◽  
Vol 09 (02) ◽  
pp. 1950016 ◽  
Author(s):  
Poonam Kumari ◽  
Madan Lal ◽  
Sunil Kumar ◽  
Radheshyam Rai ◽  
Anupinder Singh ◽  
...  

In this research paper, we utilized the traditional high-temperature solid-state reaction method to fabricate the K[Formula: see text]Na[Formula: see text]NbO3, K[Formula: see text]Na[Formula: see text]NbO3 and K[Formula: see text]Na[Formula: see text]NbO3 (abbreviated as KNN-1, KNN-2, and KNN-3, respectively) lead-free ion deficient ceramics for understanding the influence of ionic deficiency on the crystalline structure and dielectric/piezoelectric properties of the samples. X-ray diffraction patterns of these samples exhibited a perovskite tetragonal phase. Dielectric anomalies around 287∘C and 471∘C were identified as ferroelectric to ferroelectric and ferroelectric to paraelectric-transition temperatures for KNN-2 at 1[Formula: see text]kHz. It was found that the composition KNN-2 exhibit relatively high Curie temperature i.e., 471∘C. The conductivity plots confirm that the activation energies are frequency-dependent. The impedance behavior in our ceramic samples can be analyzed with the bulk/grain effect. The slope of [Formula: see text] with temperature shows negative temperature coefficient of resistance (NTCR) type behavior in proposed KNN ceramics material.


2012 ◽  
Vol 512-515 ◽  
pp. 1399-1402 ◽  
Author(s):  
Peng Xiong ◽  
Guo Qiang Tan ◽  
Hui Jun Ren

In this study, the KNbO3, NaNbO3and NaTaO3powders were synthesized by hydrothermal method and the KNN ceramics were prepared by conventional sintering technique. The physical phase constitution and morphology were analyzed by X-ray diffraction and SEM. The KNN ceramics sintering temperature and the influence of Ta5+doping on ceramic properties were explored. The results indicate that the optimal sintering temperature of KNN ceramics is 950°C, and the main phase is orthorhombic structure. After the substitution of Ta5+, the optimal sintering temperature is increased to 975°C. As the increase of doping amount, the piezoelectric properties have been significantly enhanced. The specimen doping 0.08 mol% Ta5+exhibits the enhanced electrical properties (d33=125pC/N, Qm=131, and kp=0.24).


Author(s):  
A. Leineweber ◽  
M. Löffler ◽  
S. Martin

Abstract Cu6Sn5 intermetallic occurs in the form of differently ordered phases η, η′ and η′′. In solder joints, this intermetallic can undergo changes in composition and the state of order without or while interacting with excess Cu and excess Sn in the system, potentially giving rise to detrimental changes in the mechanical properties of the solder. In order to study such processes in fundamental detail and to get more detailed information about the metastable and stable phase equilibria, model alloys consisting of Cu3Sn + Cu6Sn5 as well as Cu6Sn5 + Sn-rich melt were heat treated. Powder x-ray diffraction and scanning electron microscopy supplemented by electron backscatter diffraction were used to investigate the structural and microstructural changes. It was shown that Sn-poor η can increase its Sn content by Cu3Sn precipitation at grain boundaries or by uptake of Sn from the Sn-rich melt. From the kinetics of the former process at 513 K and the grain size of the η phase, we obtained an interdiffusion coefficient in η of (3 ± 1) × 10−16 m2 s−1. Comparison of this value with literature data implies that this value reflects pure volume (inter)diffusion, while Cu6Sn5 growth at low temperature is typically strongly influenced by grain-boundary diffusion. These investigations also confirm that η′′ forming below a composition-dependent transus temperature gradually enriches in Sn content, confirming that Sn-poor η′′ is metastable against decomposition into Cu3Sn and more Sn-rich η or (at lower temperatures) η′. Graphic Abstract


2012 ◽  
Vol 518-523 ◽  
pp. 775-779 ◽  
Author(s):  
Dong Dong Tan ◽  
De Fu Bi ◽  
Peng Hui Shi ◽  
Shi Hong Xu

The TiO2/NiFe2O4 (TN) composite nanoparticles with different mass ratios of NiFe2O4 to TiO2 were prepared via sol-gel method. X-ray diffraction was used to characterize the phase structure of TN. The results indicated that adulterating a smidgen of NiFe2O4 into the TiO2 (about 0.1%) can promote the phase transformation of TiO2, however, when the doping amount of NiFe2O4 surpasses 1%, the introduction of NiFe2O4 can inhibit the growth of TiO2 crystal grain and reduce the size of TiO2 crystal grain. The degradation experiment of methyl orange solution under UV illumination (253.7 nm) showed that the content of NiFe2O4 in the TN was higher, the photocatalytic activity of TN was worse, and the 0.1% TiO2/NiFe2O4 calcined at 400 °C presented the best photocatalytic activity.


2008 ◽  
Vol 72 (1) ◽  
pp. 201-204 ◽  
Author(s):  
A. Sumoondur ◽  
S. Shaw ◽  
I. Ahmed ◽  
L. G. Benning

AbstractIn this study, direct evidence for the formation of magnetite via a green rust intermediate is reported. The Fe(II) induced transformation of ferrihydrite, was quantified in situ and under O2-free conditions using synchrotron-based time-resolved energy dispersive X-ray diffraction. At pH 9 and Fe(II)/Fe(III) ratios of 0.5 and 1, rapid growth (6 min) of sulphate green rust and its subsequent transformation to magnetite was observed. Electron microscopy confirmed these results, showing the initial rapid formation of hexagonal sulphate green rust particles, followed by the corrosion of the green rust as magnetite growth occurred, indicating that the reaction proceeds via a dissolution-reprecipitation mechanism. At pH 7 and Fe(II)/Fe(III) ratio of 0.5, sulphate green rust was the stable phase, with no transformation to magnetite.


2020 ◽  
Vol 12 (22) ◽  
pp. 9417
Author(s):  
Jucielle Veras Fernandes ◽  
Danyelle Garcia Guedes ◽  
Fabiana Pereira da Costa ◽  
Alisson Mendes Rodrigues ◽  
Gelmires de Araújo Neves ◽  
...  

In this study, we develop ceramic formulations based on quartzite and scheelite tailings collected from mining companies in the northeast of Brazil (Rio Grande do Norte State). New ceramic samples (27 wt% of kaolin, 29 wt% of plastic clay, 11 wt% of quartzite tailing, and 0–8 wt% scheelite tailing) were uniaxially pressed in two steps (20 MPa and 50 Mpa for 20 s); dried at 110 °C for 24 h; and sintered at 1150 °C, 1200 °C, and 1250 °C. The main mineralogical phases (mullite, quartz, calcite, and anorthite) of the sintered samples were identified using X-ray diffraction (XRD). After evaluation of the physical-mechanical properties (water absorption, linear shrinkage, apparent porosity, and flexural strength), it was observed that the incorporation of scheelite tailing by up to 8 wt% did not significantly alter the properties of samples sintered at all temperatures. Our results indicate that the new ceramics formulations developed have strong potentials in manufacturing sustainable materials such as ceramic tiles and porcelain stoneware.


2012 ◽  
Vol 730-732 ◽  
pp. 100-104
Author(s):  
Agata Lisińska-Czekaj

In the present study Bi6Fe2Ti3O18 (BFTO) ceramics has been fabricated by solid state reaction from the mixture of simple oxides viz. Bi2O3, TiO2 and Fe2O3. Stoichiometric mixture of the powders was thermally analyzed so parameters of the thermal treatment were determined. The EDS measurements have shown conservation of the chemical composition of the ceramic powder after calcination. Hot-pressing method was used for final densification of ceramic samples. The crystalline structure of the sintered samples was examined by X-ray diffraction method at room temperature. It was found that BFTO ceramics sintered at T=980 °C adopted the orthorhombic structure of Aba2 (41) space group with the following elementary cell parameters: a=5.4567(2)Å, b=49.418(2) and c=5.4826(2). Details concerning the atom’s positions are presented.


1999 ◽  
Vol 574 ◽  
Author(s):  
M. C. Cheung ◽  
H. L. W. Chan ◽  
Q. F. Zhou ◽  
C. L. Choy

AbstractBarium titanate (BaTiO3) 0–3 ceramic/ceramic composite thick films (∼16μm) for ultrasonic transducer applications were fabricated by a modified sol-gel process. Nano-sized BaTiO3 powder was dispersed in a sol-gel matrix of BaTiO3 to form a 0–3 composite solution. Films were prepared by spin coating and then annealed at various temperatures. The crystallization of the composite film was studied by X-ray diffraction. The dielectric permittivity and the ferroelectric properties of the film were also measured.


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