scholarly journals Significant improvement in the piezoelectric properties and electromechanical coupling factors of wurtzite AlN compound under high pressures

Author(s):  
Z. A. A. R. Almaghbash ◽  
O. Arbouche ◽  
A. Dahani ◽  
A. Cherifi ◽  
M. Belabbas ◽  
...  
MRS Bulletin ◽  
2009 ◽  
Vol 34 (4) ◽  
pp. 277-283 ◽  
Author(s):  
Zuo-Guang Ye

AbstractRelaxor-based single crystals of complex perovskite solid solutions, Pb(Mg1/3Nb2/3)O3–PbTiO3 [PMN–PT] and Pb(Zn1/3Nb2/3)O3–PbTiO3 [PZN–PT], exhibit extraordinary piezoelectric performance, with extremely high piezoelectric coefficients, very large electromechanical coupling factors, and exceptionally high strain levels. These materials outperform the currently used Pb(Zr1–xTix)O3 [PZT] ceramics, making them the materials of choice for the next generation of electromechanical transducers for a broad range of advanced applications. In this article, recent major advances in the development of piezocrystals are reviewed in terms of crystal growth, piezoelectric properties, crystal chemistry, domain structure, and device applications.


2007 ◽  
Vol 336-338 ◽  
pp. 58-61
Author(s):  
M.H. Lente ◽  
A.L. Zanin ◽  
D. Garcia ◽  
José Antônio Eiras ◽  
L. Leija ◽  
...  

Pb(Mg1/3Nb2/3)O3-PbTiO3 based ceramics were produced by conventional sintering method and their electric-field induced electromechanical properties were determined. Large fieldinduced electromechanical coupling factors, with high piezoelectric anisotropy, were obtained in this relaxor material at relatively low DC electric bias field. A circular ultrasonic transducer with non uniform radial induced polarization was constructed using this material for field diffraction control.


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.


2021 ◽  
Author(s):  
Z. A. A. R. Almaghbash ◽  
Arbouche Omar ◽  
A. Dahani ◽  
A. Cherifi ◽  
M. Belabbas ◽  
...  

Abstract This work describes a theoretical study of the pressure effect in structural, elastic, piezoelectric and dielectric properties as well as electromechanical coupling factors of wurtzite AlN, obtained by ab-initio calculations using pseudo-potential plane waves (PP-PW) that combine the density functional theory (DFT) and density functional perturbation theory (DFPT). The results of the calculation indicate that the parameters of AlN crystal cells and the volume of AlN crystallin crystal cells decrease notably with increasing pressures from 0 to 40 GPa. Due to an increase in the value of the direct piezoelectric constant ( Tand a decrease in the value of the elastic constant (h), there is a significant improvement in the value of the converse piezoelectric constant (i). The improvement in the piezoelectric value leads to a higher value in electromechanical coupling coefficient. Our results agree well with previous theoretical and experimental research. We hope that our results will provide guidelines for the realistic application as well as further research of high-performance compounds appropriate for applications in a multitude of fields of study, such as biomedical engineering.


2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
Peng Qi ◽  
Juan Du ◽  
Guozhong Zang

Lead-free alkaline niobate-based piezoceramics, (Na0.52K0.435Li0.045)Nb0.87Sb0.08Ta0.05O3 (abbreviated KNLNT-S8), were prepared by conventional solid-state sintering method. The effects of sintering temperature on microstructure and piezoelectric properties of the (Li, Sb, Ta)-modified (Na, K) NbO3 were investigated. Microstructure of the samples sintered at different temperatures was observed by scanning electron microscopy (SEM) and optical microscopy. The KNLNT-S8 sample sintered at 1100°C possessed highest piezoelectric constant and high-field piezoelectric strain coefficient of 332 pC/N and 530 pm/V, respectively, with electromechanical coupling factors of 0.52 and of 0.48.


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.


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.


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


2002 ◽  
Vol 17 (6) ◽  
pp. 1376-1384 ◽  
Author(s):  
Marlyse Demartin Maeder ◽  
Dragan Damjanovic ◽  
Cyril Voisard ◽  
Nava Setter

The dynamic piezoelectric response of SrBi4Ti4O15 ceramics with Aurivillius structure was investigated at high alternating stress, low frequencies (0.01 to 100 Hz), and temperatures from 20 to 200 °C. The piezoelectric nonlinearity, observed only at high pressures (>10 MPa) and elevated temperatures (>150 °C), is interpreted in terms of contributions from non-180° domain walls. At weak fields, the frequency dependence of the longitudinal piezoelectric coefficient was explained in terms of Maxwell–Wagner piezoelectric relaxation. The Maxwell–Wagner units are identified as colonies that consist of highly anisotropic grains which sinter together, and whose distribution in the ceramic is strongly dependent on sintering conditions.


2013 ◽  
Vol 479-480 ◽  
pp. 3-7
Author(s):  
Chun Huy Wang

In the present study, various quantities of Bi2O3were added into 0.98(Na0.5K0.5)NbO3-0.02Bi(Na0.93K0.07)TiO3(0.98NKN-0.02BNKT) ceramics. It was found that 0.98NKN-0.02BNKTwith the addition of 0~0.5 wt.% Bi2O3exhibit relatively good piezoelectric properties. For 0.98NKN-0.02BNKT ceramics, the electromechanical coupling coefficients of the planar modekpand the thickness modektreach 0.40 and 0.47,respectively. For 0.98NKN-0.02BNKT ceramics with the addition of 0.3 wt.% Bi2O3, the electromechanical coupling coefficients ofthe planar modekpand the thickness modektreach 0.50 and 0.53, respectively. It is obvious that 0.98NKN-0.02BNKT solid solution ceramics by adding low quantities of Bi2O3is one of the promising lead-free ceramics for electromechanical transducer applications.


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