(1-x)(K0.44Na0.52Li0.04)(Nb0.84Ta0.10Sb0.06)O3-xSrTiO3 Lead Free Piezoelectric Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 1896-1898
Author(s):  
Ming He Cao ◽  
Wan Qiang Wang ◽  
Zhi Yong Yu ◽  
Hua Hao ◽  
Han Xing Liu

(1-x)(K0.44Na0.52Li0.04)(Nb0.84Ta0.10Sb0.06)O3-xSrTiO3 (KNNT-ST) lead free piezoelectric ceramics have been synthesized by a solid state reaction method. The effect of SrTiO3 content on the piezoelectric properties, sintering behavior and microstructure of (1-x) KNNT-x ST ceramics was investigated. The experimental results showed that the addition of SrTiO3 can restrain the volatilization of Na ions and K ions and improve relative density of the samples. A morphotropic phase boundary between orthorhombic and tetragonal phases is found in the composition range of 0.03<x<0.05. The piezoelectric properties can be enhanced for (1-x) KNNT-x ST ceramics near the morphotropic phase boundary.

2014 ◽  
Vol 787 ◽  
pp. 242-246
Author(s):  
Rui Lin Wu ◽  
Tomoaki Karaki ◽  
Jiang Tao Zeng ◽  
Liao Ying Zheng ◽  
Wei Ruan ◽  
...  

Lead-based piezoelectric ceramics have excellent piezoelectric properties with the compositions near the rhombohedral-tetragonal morphotropic phase boundary (MPB)[1,2]. In these materials, the dielectric and piezoelectric properties show the maximal values at MPB. For lead-free piezoelectric ceramics, finding the MPB area is a promising way to improve their properties. In this paper, the (1-x-y)BaZrO3-x(K0.45Na0.5Li0.05)NbO3-yBi (Mg0.5Ti0.5)O3 lead-free piezoelectric ceramics were prepared by solid-state reaction method, and their piezoelectric properties and dielectric properties were investigated. With the increase of KNLN content, the crystal structure changed from rombohedral phase to tetragonal phase, thus existed a MPB[3,4] between rombohedral and tetragonal phase. At room temperature, the specimen with the composition at MPB (x=0.93, y=0.01) shows the optimal piezoelectric properties (d33=225pC/N and kp=45%), which indicates that this material is a potential lead-free piezoceramic.


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. %.


2008 ◽  
Vol 368-372 ◽  
pp. 1908-1910 ◽  
Author(s):  
Wei Zhao ◽  
He Ping Zhou ◽  
Yong Ke Yan ◽  
Dan Liu

A lead-free piezoelectric ceramic binary system based on bismuth sodium titanate (Bi0.5Na0.5)TiO3 (BNT)-bismuth potassium titanate (Bi0.5K0.5)TiO3 (BKT) was synthesized by conventional mixed-oxide technique. The XRD analysis showed that the rhombohedral-tetragonal morphotropic phase boundary (MPB) of the Bi0.5 (Na1-xKx)0.5 TiO3 system was in the composition range of x = 0.16 ~ 0.20. In addition, the piezoelectric properties of this system were also investigated. It was indicated that the piezoelectric properties are better with the compositions near the rhombohedral phase within the MPB than the compositions near the tetragonal phase.


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.


2018 ◽  
Vol 6 (41) ◽  
pp. 19967-19973 ◽  
Author(s):  
Zhenyong Cen ◽  
Yu Huan ◽  
Wei Feng ◽  
Yan Yu ◽  
Peiyao Zhao ◽  
...  

Lead-free (1 − x)(0.96K0.46Na0.54Nb0.98Ta0.02O3–0.04Bi0.5(Na0.82K0.18)0.5ZrO3)–xCaZrO3 ((1 − x)(0.96KNNT–0.04BNKZ)–xCZ) piezoelectric ceramics were prepared by the conventional solid-state reaction method.


2012 ◽  
Vol 531-532 ◽  
pp. 632-635
Author(s):  
Min Hong Jiang ◽  
Xin Yu Liu ◽  
Guo Hua Chen ◽  
Jia Feng Ma ◽  
Gui Sheng Zhu ◽  
...  

(0.996-x) K0.5Na0.5NbO3- 0.004 BiFeO3- x LiSbO3 (x =0.00, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07) lead-free piezoelectric ceramics were prepared by the conventional mixed oxide method. The compositional dependence of the phase structure and the electrical properties of the ceramics were studied. A morphotropic phase boundary between the orthorhombic and tetragonal phases was identified in the composition range of 0.03 < x < 0.06. With the content of LS increases, the size of the pores significantly decreases. However, adding larger amount of LS makes the pore size increase slightly. The (0.996-x)KNN-0.004 BF-xLS(x=0.05) ceramics possess good electrical properties: d33 = 280 pC/N, kp = 53.3%, Tc = 345 °C, εr = 1613, Tan δ =2.07%. These results show that the ceramic is a promising lead-free piezoelectric material.


2012 ◽  
Vol 724 ◽  
pp. 123-126
Author(s):  
Soon Young Kweon ◽  
Youn Ki Lee ◽  
Sung Lim Ryu

The (Na0.52K0.44)(Nb0.9Sb0.06)O3-0.04LiTaO3 (NKNS-LT) ceramics doped with various Cu2O contents were prepared by the conventional solid state reaction method. The Cu2O content was varied in the range of 0.1~0.4 wt%. The effects of Cu on microstructure, crystallographic phase transition, and piezoelectric properties were investigated. The material with perovskite structure had a tetragonal phase (T1) when Cu2O concentration was less than 0.3 wt% and it was transformed to another tetragonal phase (T2) when the Cu2O amount was greater than 0.3 wt%. The phase boundary between T1 and T2 phases was appeared at around 0.3 wt% of Cu2O concentration. The piezoelectric properties were shown the maximum values at the composition of the phase boundary. The electro-mechanical coupling factor (kp) was 0.42 and the piezoelectric charge constant (d33) was 245 pC/N at the 0.3 wt% of Cu2O concentration.


2011 ◽  
Vol 01 (04) ◽  
pp. 471-478 ◽  
Author(s):  
HONGLIANG DU ◽  
SHAOBO QU ◽  
ZHUO XU ◽  
XIAOYONG WEI ◽  
WANCHENG ZHOU ◽  
...  

In order to clarify the Na/K ratios dependence of piezoelectric properties, ( K 1-x Na x) NbO 3 ceramics were prepared by conventional solid-state sintering at x = 0.4–0.6 with a smaller compositional interval (0.02 mol). The results demonstrate that the Na/K ratios have obvious effect on piezoelectric and ferroelectric properties of ( K 1-x Na x) NbO 3 ceramics. Piezoelectric and ferroelectric properties show the maximum (d33 = 147 pC/N, kp = 0.40, and Pr = 24 μC/cm2) at x = 0.54, which is not consistent with conventional viewpoint. The reasons should be attributed to the existence of a phase boundary at x = 0.54 mol, which is similar to the morphotropic phase boundary in Pb(Zr,Ti)O3 ceramics.


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