Effect of Pre-Calcined Method on Dielectric, Ferroelectric, and Piezoelectric Properties of Lead-Free Piezoelectric Lix(K0.5Na0.5)1-x(Nb0.8Ta0.2)O3 Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 1218-1221
Author(s):  
Min Chang Kuan ◽  
Kai Huang Chen ◽  
Chien Min Cheng ◽  
Chun Cheng Lin ◽  
Shih Fang Chen

The structure and electrical characteristics of the lead-free Lix(K0.5Na0.5)1-x(Nb0.8Ta0.2)O3 (x=0~0.05) piezoelectric ceramics for the conventional solid-state reaction method and the B-side pre-calcined method were achieved and compared. For the B-side pre-calcined method, the lead-free ceramic material exhibited the excellent electrical and piezoelectric properties. The relative dielectric constant (εr) and loss (tan δ) of the Lix(K0.5Na0.5)1-x(Nb0.8Ta0.2)O3 for x=0.03 using the B-side pre-calcined method were 1223 and 0.021, respectively. In addition, the electromechanical coupling factors (kp) and Curie temperature (Tc) was 48.5 % and 315°C. Finally, the electrical properties of the lead-free Lix(K0.5Na0.5)1-x(Nb0.8Ta0.2)O3(x=0~0.05) homogeneity ceramics improved by the B-side pre-calcined method were also investigated and discussed.

2011 ◽  
Vol 328-330 ◽  
pp. 1131-1134
Author(s):  
Qian Chen ◽  
Zhi Jun Xu ◽  
Rui Qing Chu ◽  
Yong Liu ◽  
Ming Li Chen ◽  
...  

Lead-free piezoelectric ceramics Sr2Bi4-xGdxTi5O18 were prepared by conventional solid-state reaction method. Pure bismuth layered structural ceramics with uniform gain size were obtained in all samples. The effect of Gd-doping on the dielectric, ferroelectric and piezoelectric properties of Sr2Bi4Ti5O18 ceramics were also investigated. It was found that that Gd3+ dopant gradually decreased the Curie temperature (Tc) with the lower dielectric loss (tand) of SBTi ceramics. In addition, Gd-doping with appropriate content improved the ferroelectric and piezoelectric properties of the SBTi ceramics. The piezoelectric constant (d33) of the Sr2Bi3.9Gd0.1Ti5O18 ceramic reached the maximum value, which is 22 pC/N. The results showed that the Sr2Bi4-xGdxTi5O18 ceramic was a promising lead-free piezoelectric material.


2009 ◽  
Vol 66 ◽  
pp. 238-241
Author(s):  
Xiao Fang Liu ◽  
Hua Jun Sun ◽  
Ming Wei ◽  
C.X. Xiong

The Nb modified PZT piezoelectric ceramic was synthesized by conventional solid-state reaction, where all of different particle sizes had the same physical properties. 0-3 modified PZT/PVDF composites were formed by hot-pressing method. The particle size effect of modified PZT on the relative dielectric and piezoelectric properties of the composites were investigated. The relative dielectric constant εr, piezoelectric constant d33 and electromechanical coupling factor kp were higher in the composite containing larger PZT particle size. The microstructures of the composites were studied by SEM, the composite with the finer PZT particle size was more homogeneous, but larger particle size was easy to be contacted. In a high volume fraction particle-loaded composite, some piezoelectric ceramic particle appeared to be in contact, as in a 1-3 connectivity pattern. The larger particle size of modified PZT itself could be seen as the grain of modified PZT contact in a 1-3 connectivity pattern and easy to be contacted each other compared to the finer particle size in the composites, thus reducing the resistance of the composites and the poling process became effective, which led to higher properties. The optimal particle size of PZT is about 100μm, the Nb modified PZT/PVDF (volume fraction 70/30) composite show higher dielectric and piezoelectric properties than the others, εr=156.6, d33=69pC/N and kp=0.358.


2016 ◽  
Vol 697 ◽  
pp. 211-215 ◽  
Author(s):  
Lin Ling Li ◽  
Yu Hua Zhen

A strong desire for environmental protection and human health care urgently requires us to find an environmental friendly type of piezoelectric material to replace the lead ones. In this study, (LixK0.5-xNa0.5)(Nb0.97Sb0.03)O3-1mol%CuO (x = 0, 0.05, 0.1 ,0.2 ,0.5, abbreviated as CuO-LxKNNS) lead-free piezoelectric ceramics have been fabricated by a conventional solid-state reaction route. We focused on the comparison of buried powder sintering with exposed sintering. The effect of buried powder sintering method on density, structure and dielectric, piezoelectric properties of CuO-LxKNNS ceramics has been investigated. It was found that the density increased greatly when the buried powder sintering method was used, which was effective in inhibiting the volatilization of alkali metal oxides compared with exposed sintering method. Piezoelectric and dielectric properties showed a similar tendency with the density. These ceramics showed an obvious phase transition with increasing the Li content. CuO-LxKNNS ceramics showed orthorhombic symmetry when x= 0, but turned to be tetragonal symmetry when x ≥ 0.05. The optimal composition of CuO-LxKNNS with buried powder sintering method was x = 0.05 sintered at 1020 °C, for which the maximum value of the piezoelectric constant (d33) was 180pC/N, the density (ρ) was 4.40g/cm3, the room temperature relative dielectric constant (εr) was 270 and the dielectric loss (tanδ) was 0.07.


2012 ◽  
Vol 549 ◽  
pp. 651-654 ◽  
Author(s):  
Zhi Wen Zhu ◽  
Xin You Huang ◽  
Hai Tang Hua ◽  
Yan Li

Ba0.85Ca0.15Ti0.9Zr0.1O3-xLi2CO3 lead-free piezoelectric ceramics (abbreviated as BCZT-xLi) were prepared by conventional solid state reaction method. The microstructure, piezoelectric properties and dielectric properties were studied for BCZT-xLi samples doped with different Li2CO3 content(x= 0, 0.05, 0.1 0.2 0.3, 0.4wt. %). The results show that the piezoelectric constant(d33), planar electron mechanical coupling coefficient(kp) and thickness electron mechanical(kt) of BCZ-T-xLi ceramics increase firstly and decreases subsequently with increasing of Li+ doping amount, the dielectric loss(tanδ) of BCZT-xLi ceramics decreases firstly and then increases at the same time while Li+ doping amount increases. But the r-elative permittivity (εr) of BCZT-xLi ceramics increases all the time. With the in-creasing of the amount of Li2CO3 doped the grain size of BCZT-Li ceramic first increases and then decreases. The BCZT-xLi ceramics display the optimum properties (d33=83, tanδ=0.035, εr=2020, kp=0.41, kt=0.046) while Li2CO3 doped amount is 0.20wt. %.


Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 705
Author(s):  
Yunfeng Deng ◽  
Junjun Wang ◽  
Chunxiao Zhang ◽  
Hui Ma ◽  
Chungeng Bai ◽  
...  

Structural, ferroelectric, dielectric, and piezoelectric properties of K0.5Na0.5NbO3-LiTaO3-xmol%MnO2 lead-free piezoelectric ceramics with 0.0 ≤ x ≤ 0.3 were studied. The ceramic samples were synthesized through the conventional solid-state reaction method. The MnO2 addition can reduce the sintering temperature of KNLNT ceramics. Compared with undoped KNLNT ceramic, the piezoelectric measurements showed that piezoelectric properties of K0.5Na0.5NbO3-LiTaO3-xMnO2 were improved (d33 = 251 pC/N) when x = 0.1. In addition, KNLNT-xMnO2 ceramics have larger Pr(20.59~21.97 μC/cm2) and smaller Ec(10.77~6.95 kV/cm), which indicates MnO2 has excellent softening property, which improves the ferroelectric properties of KNLNT ceramics This work adds relevant information regarding of potassium sodium niobate K0.5Na0.5NbO3 (KNN) when doped Li, Ta, Mn at the B-site.


2011 ◽  
Vol 239-242 ◽  
pp. 994-997 ◽  
Author(s):  
Chien Min Cheng ◽  
Ming Chang Kuan ◽  
Kai Huang Chen ◽  
Chia Chi Shih ◽  
Jiann Sheng Jiang

Lead-free potassium sodium niobate ceramic, with the nominal composition of K0.5Na0.5NbO3, were synthesized by conventional solid state sintering, and its dielectric, ferroelectric, and piezoelectric properties were characterized as a function of sintering temperature. The orthorhombic to tetragonal phase transition (TO-T) temperature of K0.5Na0.5NbO3ceramic sample was about 220°C, and its Curie temperature was about 420°C. The high bulk density was obtained for all compositions by solid state sintering in air. Bulk density was increased with temperature and it reached to 4.4 g/cm3. The K0.5Na0.5NbO3ceramic sample sintered at 1100°C was optimized densification properties. In addition, the ferroelectric loop and dielectric characteristics dependence of different sintering temperature for K0.5Na0.5NbO3ceramic sample was obtained. Finally, we found that the piezoelectric constant (d33) was 160 pC/N, high remanent polarization (Pr) was 33mC/cm2, and high electromechanical coupling coefficients (kP) was about of 45%.


2015 ◽  
Vol 44 (17) ◽  
pp. 7797-7802 ◽  
Author(s):  
Yang Zhang ◽  
Lingyu Li ◽  
Bo Shen ◽  
Jiwei Zhai

Lead free piezoelectric ceramics have been prepared by the conventional solid state reaction method and the effects of SrZrO3 content on polymorphic phase transition are investigated.


Author(s):  
Nguyen TruongTho

The <em>(1-x)</em>BiFe<sub>0</sub><sub>.91</sub>(Mn<sub>0</sub><sub>.47</sub>Ti<sub>0.53</sub>)<sub>0.09</sub>O<sub>3</sub>–<em>x</em>BaTiO<sub>3</sub> (BFMT–BT) lead-free ceramics have been fabricated by the conventional solid-state reaction method. The phase structure of BFMT-BT investigated by <em>X</em>–ray diffraction shows a single perovskite phase. Although 20% mol of Bi<sub>2</sub>O<sub>3</sub> was added to the raw materials, the evaporation of Bi<sup>3+</sup> ions during calcining and sintering processes is from 20 to 30% wt. relative to other elements. The effect of BaTiO<sub>3</sub>content on electrical properties of BFMT-BT ceramic has been investigated. At BaTiO<sub>3</sub>concentration of 0.3 mol and the sintering temperature of 950<sup>o</sup>C, electrical properties of ceramics are best with the density (<em>r</em>) of 7.6 g/cm<sup>3</sup>, the electromechanical coupling factor (<em>k<sub>p</sub></em>) of 0.28, the dielectric constant (<em>ε<sub>r</sub></em>) of 1028, and the difference in polarizations at zero field is about 10.5 mC/cm<sup>2</sup>.


2006 ◽  
Vol 320 ◽  
pp. 23-26 ◽  
Author(s):  
Yuji Hiruma ◽  
Kazushige Yoshii ◽  
Rintaro Aoyagi ◽  
Hajime Nagata ◽  
Tadashi Takenaka

The piezoelectric properties of a solid solution based on the three components of bismuth sodium titanate, (Bi1/2Na1/2)TiO3 (BNT), bismuth potassium titanate, (Bi1/2K1/2)TiO3 (BKT), and barium titanate, BaTiO3 (BT), that is, x(Bi1/2Na1/2)TiO3-y(Bi1/2K1/2)TiO3-zBaTiO3 [BNBKy:z(x); x+y+z=1] are investigated. Fine piezoelectric properties in lead-free piezoelectric ceramics were obtained near the MPB composition, and the highest electromechanical coupling factors, k33 and kp, and piezoelectric constant, d33, were 0.58 and 0.36 for BNBK2:1(0.89) and 181 pC/N for BNBK2:1(0.88), respectively. In this study, we also measured the depolarization temperature, Td, from the temperature dependence of dielectric and piezoelectric properties.


2016 ◽  
Vol 872 ◽  
pp. 103-108
Author(s):  
Pichitchai Butnoi ◽  
Supalak Manotham ◽  
Pharatree Jaita ◽  
Ratabongkot Sanjoom ◽  
Denis Russell Sweatman ◽  
...  

In this research, the Bi0.5(Na0.80K0.20)0.5Ti0.99Ti0.10O3 were prepared via a conventional solid-state reaction method, and their properties were related with calcination temperature. The crystalline structure of BNKTZ ceramics was assessed by X-ray diffraction (XRD) method. Other physical properties, i.e. porosity, density, microstructure, and electrical properties were determined. XRD patterns for all samples showed a pure perovskite, where coexistence between rhombohedral and tetragonal phases was observed for some conditions. The optimum dielectric constant was obtained for the ceramic calcined at 800 °C. The ferroelectric and piezoelectric properties were improved and showed the highest values for the calcination temperature around 900-1000°C. The improvements of ferroelectric and piezoelectric properties were proposed to be due to the ceramics had compositions closed to MPB composition. Furthermore, density also had a contribution for the improvements.


Sign in / Sign up

Export Citation Format

Share Document