Pb VOLATILIZATION EFFECT ON DIELECTRIC AND PIEZOELECTRIC PROPERTIES IN A Ta-DOPED PMN-PT CERAMIC THICK DISK

2005 ◽  
Vol 19 (01n03) ◽  
pp. 549-552 ◽  
Author(s):  
C. ZHANG ◽  
J. T. WANG ◽  
S. X. SHEN ◽  
Y. FENG ◽  
I. AKUJOBI ◽  
...  

A thick ceramic disk of 0.7 Pb ( Mg 1/3( Nb 0.9 Ta 0.1)2/3) O 3-0.3 PbTiO 3 ( PMNT - PT ) was prepared by columbite precursor method with PbO powder buffer surrounding the disk during the sintering process. The dielectric and piezoelectric properties and the microstructure of PMNT - PT samples cut from the different depths of the disk are studied. The phase purity is homogenous in the whole disk within our x-ray diffraction resolution. The dielectric constants, and the piezoelectric effect, d 33, vary with different samples. The samples cut from the middle parts of the disk have the higher d 33. It is believed that the sample processes, especially the Pb volatilization is responsible for these results.

2007 ◽  
Vol 336-338 ◽  
pp. 18-20
Author(s):  
Guo Yuan Zhou ◽  
Jin Song Pan ◽  
Xiao Wen Zhang

Ferroelectric ceramics of (1x)(0.8PMN0.2PNN)xPT (x = 0.280.43) were synthesized by the columbite precursor method. Their phase structures as well as the dielectric, ferroelectric and piezoelectric properties were investigated. X-ray diffraction (XRD) results demonstrate that the morphotropic phase boundary (MPB) of this system lies in the composition range of x = 0.31–0.37. Examination of the dielectric behavior indicates that the ceramics exhibit high dielectric constants near the MPB compositions. In addition, the piezoelectric properties of the ceramics were found quite well around the MPB. The interrelated mechanism was also discussed.


2013 ◽  
Vol 368-370 ◽  
pp. 760-763
Author(s):  
Chun Huy Wang ◽  
Ming Qiu Wei

(Na0.5K0.5)NbO3 with Bi0.5(Na0.97K0.03)0.5TiO3 with x≤0.05 has been prepared by the conventional mixed oxide process. X-ray diffraction analysis revealed that, during sintering, all the Bi(Na0.97K0.03)TiO3 diffuses into the lattice of (Na0.5K0.5)NbO3 to form a solid solution with a perovskite structure. A morphotropic phase boundary (MPB) between orthorhombic (O) and rhombohedral (R) was found at the composition 0.98(Na0.5K0.5)NbO3-0.02Bi0.5(Na0.97K0.03)0.5TiO3 [abbreviated as 0.98NKN-0.02BNKT] with correspondingly enhanced dielectric and piezoelectric properties. For 0.98NKN-0.02BNKT ceramics, the electromechanical coupling coefficients of the planar mode kp and the thickness mode kt reach 0.33 and 0.49, respectively, after sintering at 1100 oC for 3 h. The ratio of the thickness coupling coefficient to the planar coupling coefficient is 1.48. With suitable Bi0.5(Na0.97K0.03)0.5TiO3 concentration, a dense microstructure and good electrical properties are obtained.


2007 ◽  
Vol 280-283 ◽  
pp. 227-230 ◽  
Author(s):  
X. Zeng ◽  
Ai Li Ding ◽  
X.S. Zheng ◽  
Yong Zhang ◽  
Ping Sun Qiu

La-modified PZN-PZT compositions with representative formula Pb1-0.7xLa0.7x(Zn1/3Nb2/3)0.3- (Zr0.55Ti0.45)0.7(1-x/4)O3 were prepared by the columbite precursor method. La content, x, was varied from 0 to 8mol%. Effects of La doping on microstructure, dielectric and piezoelectric properties were investigated. The results showed that in present system La doping promotes the formation of pyrochlore phase and the phase shifted from rhombohedral to tetragonal structure with increasing La content. It was also found that La doping makes dielectric permittivity maximum decrease and the degree of diffuse phase transition enhance. Appropriate amount of La doping could improve the piezoelectric properties.


1999 ◽  
Vol 14 (11) ◽  
pp. 4307-4318 ◽  
Author(s):  
S. Hiboux ◽  
P. Muralt ◽  
T. Maeder

In situ reactively sputter deposited, 300-nm-thick Pb(Zrx, Ti1−x)O3 thin films were investigated as a function of composition, texture, and different electrodes (Pt,RuO2).X-ray diffraction analysis, ferroelectric, dielectric, and piezoelectric measurements were carried out. While for dielectric properties bulklike contributions from lattice as well as from domains are observed, domain wall contributions to piezoelectric properties are very much reduced in the morphotropic phase boundary (MPB) region. Permittivity and d33 do not peak at the same composition; the MPB region is broadened up and generally shifted to the tetragonal side.


2015 ◽  
Vol 05 (02) ◽  
pp. 1550014 ◽  
Author(s):  
Dabin Lin ◽  
Haohua Chen ◽  
Zhenrong Li ◽  
Zhuo Xu

x Pb ( In 1/2 Nb 1/2) O 3- Pb ( Mg 1/3 Nb 2/3) O 3- PbTiO 3(x PIN –y PMN –z PT ) ternary ceramics with morphotropic phase boundary (MPB) composition were synthesized by columbite precursor method. x PIN –y PMN –z PT phase diagram was investigated by x-ray diffraction and dielectric measurements. According to the results of dielectric measurements, the Curie temperatures (Tc) and rhombohedral to tetragonal phase transition temperature (Tr−t) were found to be in the range of 173–212°C and 114–155°C, respectively, indicating that the Tr-t was increased with adding PIN component. In the MPB region, the highest Tr-t = 155° C was found in 0.32PIN–0.38PMN–0.30PT ceramic, that greatly expanded temperature usage range.


1999 ◽  
Vol 14 (12) ◽  
pp. 4581-4586 ◽  
Author(s):  
Xiaowen Zhang ◽  
Fei Fang

(1–x)PMN–xPT[PMN, Pb(Mg1/3Nb2/3)O3; PT, PbTiO3] system ferroelectric ceramics with x = 0.30, 0.33, 0.35, and 0.38 were synthesized by the columbite precursor method. Their structure and dielectric behavior were investigated. X-ray diffraction results demonstrate that no two-phase region is presented, but a quasi-cubic to tetragonal phase boundary lies between x = 0.30 and 0.33. Examination of the dielectric behavior reveals that the transformation from relaxor to normal ferroelectric behavior across the morphotropic phase boundary (MPB) is successive and continuous. It is suggested that x 4 0.30 to 0.33 is the composition of MPB for the PMN–PT system. The MPB is also a boundary for the PMN–PT system to transform from relaxor to normal ferroelectrics.


2013 ◽  
Vol 1507 ◽  
Author(s):  
Dalei Wang ◽  
Shundong Bu ◽  
Guoxi Jin ◽  
RuiDai ◽  
Dengren Jin ◽  
...  

ABSTRACT(1-x)(Bi0.8Gd0.2)FeO3-xPbTiO3 (BGF-PT) solid solutions ceramics of x=0.55,0.50,0.4975, 0.49 and 0.45 were prepared by the mixed oxide method. Gd3+ of 20 at% was introduced into the Bi3+ site to improve the dielectric and piezoelectric properties of BFPT without causing the significant reduction of Curie temperature (Tc). X-ray diffraction analysis shows a transformation from the tetragonal (T) to rhombohedral (R) phase with the increase of BGF content. The morphotropic phase boundary was determined by measuring the dielectric and piezoelectric properties of BGF-PT within a wide composition range. BGF-PT for x=0.4975 shows the coexistence of T and R phases with the dielectric constant and loss of about 895 and 0.031 respectively at the frequency of 102 Hz.


2014 ◽  
Vol 700 ◽  
pp. 148-151
Author(s):  
Gui Gui Peng ◽  
Shun Min Hu ◽  
De Yi Zheng

It is well known that piezoelectric ceramics are wildly used in many fields such as electrical sensors, actuators, alarm equipments etc. In this paper,the microstructure and the piezoelectric properties of Pb(Zr1/2Ti1/2)1-x(Nb2/3Mg1/3)xO3 (PMNZT) were studied. A novel B-site precursor method was adopted for preparing of Pb(Zr1/2Ti1/2)1-x(Nb2/3Mg1/3)xO3 samples. For investigating the crystallographic phase and microstructure of the samples, X-ray diffraction(XRD) and scanning electron microscopy(SEM) methods have been adopted respectively. The results show that a pure perovskite structure can be obtained after sintering at 1220°C for 2h. Through this experiment, it has been found that when sintering at 1220°C for 2h and the amounts of the Pbx(Nb2/3Mg1/3)xO3 (PMN) is 0.14, the Pb(Zr1/2Ti1/2)1-x(Nb2/3Mg1/3)xO3 samples are with the best electrical properties as follows: dielectric constant (ε) is 1858, dielectric loss(tanδ) is 0.017, electromechanical coupling coefficient (Kp) is 0.515, piezoelectric constant(d33) is 362PC/N


2011 ◽  
Vol 284-286 ◽  
pp. 1408-1411
Author(s):  
Yan Li ◽  
Yan Jie Zhang ◽  
Rui Qing Chu ◽  
Zhi Jun Xu ◽  
Qian Chen ◽  
...  

La2O3-doped lead-free 0.82Bi0.5Na0.5TiO3-0.18Bi0.5K0.5TiO3(abbreviated to 0.82BNT-0.18BKT) piezoelectric ceramics were synthesized by the conventional mixed-oxide method, and the effect of La2O3addition on the dielectric and piezoelectric properties was investigated. X-ray diffraction (XRD) patterns show that La2O3diffuses into the lattice of the 0.82BNT-0.18BKT ceramics to form a solid solution with a pure perovskite structure. SEM images indicate that the grain size of the 0.82BNT-0.18BKT ceramics increased with the addition of La2O3doping. The electrical properties of 0.82BNT-0.18BKT ceramics have been greatly improved by certain amount of La2O3substitutions. At room temperature, the 0.82BNT-0.18BKT ceramics doped with 0.25 wt. % La2O3exhibited the optimum properties with high piezoelectric constant (d33= 142 pC/N) and high planar coupling factor (kp= 0.23).


2007 ◽  
Vol 280-283 ◽  
pp. 251-254 ◽  
Author(s):  
Su Chuan Zhao ◽  
Lina Zhang ◽  
Guo Rong Li ◽  
Liao Ying Zheng ◽  
Ai Li Ding

Na0.42K0.08Bi0.5TiO3 and Na0.45K0.05Bi0.5TiO3 ceramics were fabricated by the solid-state reaction. The structures were determined by X-ray diffraction. Dielectric, ferroelectric and piezoelectric properties of the ceramics were measured and discussed. The ceramics have a single perovskite phase with rhombohedral symmetry at room temperature. The thermal variations of the permittivity follow the law 1/ e − 1/ em = C(T − Tm)2 which is the character of typical relax ferroelectrics, when temperature is higher than the temperature of the maximum of dielectric constant (Tm). The depolarization temperature (Td) of spontaneous polarization is 215oC for Na0.45K0.05Bi0.5TiO3 and 152oC for Na0.42K0.08Bi0.5TiO3 respectively. There exist two different dielectric behaviors of the Na0.42K0.08Bi0.5TiO3 ceramic, without and after poling. Na0.45K0.05Bi0.5TiO3 possesses relatively high kt and Td. The use for device application has been indicated.


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