scholarly journals Sintering and Characterization of (Li, Sb, Ta)-Modified (Na, K)NbO3 Lead-Free Ceramics

2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
Peng Qi ◽  
Juan Du ◽  
Guozhong Zang
Keyword(s):  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Lead Free Ceramics ◽  
Different Temperatures ◽  
Piezoelectric Strain ◽  
Strain Coefficient ◽  
Coupling Factors ◽  
Sintering Method

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.

Effect of Bi2O3 Addition on the Microstructure and Electrical Properties of Lead-Free (Na0.5K0.5)NbO3-Bi0.5(Na0.93K0.07)0.5TiO3 Ceramics

2013 ◽  
Vol 479-480 ◽  
pp. 3-7
Author(s):  
Chun Huy Wang
Keyword(s):  
Solid Solution ◽  
Electrical Properties ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Coupling Coefficients ◽  
Electromechanical Transducer ◽  
Lead Free Ceramics ◽  
Thickness Mode ◽  
Planar Mode

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.

High Piezoelectric Properties and High TC in KNN-Based Lead-Free Ceramics Sintered in Reducing Atmosphere

2018 ◽  
Vol 281 ◽  
pp. 628-633
Author(s):  
Yi Chao Zhen ◽  
Zhen Yong Cen ◽  
Wei Feng ◽  
Xiao Hui Wang ◽  
Long Tu Li
Keyword(s):  
Piezoelectric Properties ◽  
Rhombohedral Phase ◽  
Lead Free ◽  
Reducing Atmosphere ◽  
Lead Free Ceramics ◽  
Commercial Applications ◽  
T Phase ◽  
Sintering Method ◽  
Mn Doped ◽  
Piezoelectric Constants

Lead-free MnO doped 0.955K0.5Na0.5NbO3-0.045Bi0.5Na0.5ZrO3(abbreviate as KNN-0.045BNZ) ceramics have been prepared by a conventional solid-state sintering method in a reducing atmosphere. The addition of MnO suppresses grain growth and eliminates the liquid phase. MnO dopant changes the crystalline structures of KNN-0.045BNZ ceramics from the classical Morphotropic Phase Boundary (MPB) with rhombohedral phase (R) and tetragonal phase (T) to the suppressed MPB with R/T phase. The 0.4% MnO doped KNN-0.045BNZ ceramics show an excellent electrical properties with quasi static piezoelectric constantd33=300 pC/N, Curie temperatureTC= 350 °C, insulation resistivity ρ=4.83 × 1011(Ω・cm), and high field piezoelectric constants =438 pm/V (atEmax= 25 kV/cm). The results indicate that the 0.4%Mn doped KNN-0.045BNZ ceramic is a promising lead-free piezoelectric candidate material for commercial applications.

Investigation on Electrical Properties of CaCu3Ti4O12-Modified (Na,Bi)TiO3-BaTiO3 Lead Free Piezoceramics

2014 ◽  
Vol 887-888 ◽  
pp. 289-293
Author(s):  
Jing Chang Zhao ◽  
Zhen Lai Zhou
Keyword(s):  
Electrical Properties ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Mechanical Quality Factor ◽  
Lead Free ◽  
Lead Free Ceramics ◽  
Structure Morphology

(Na,Bi)TiO3-BaTiO3lead free piezoelectric ceramics were fabricated with modification of CaCu3Ti4O12additives. The phase structure, morphology, dielectric and piezoelectric properties of prepared samples were investigated, respectively. It was found that CaCu3Ti4O12additives evidently improve the polarization properties of (Na,Bi)TiO3-BaTiO3lead free ceramics and the obtained samples exhibit an excellent piezoelectric properties (electromechanical coupling factorKp=31%, mechanical quality factorQm=151 and piezoelectric constantd33=160pC/N). According to results, the effect of CaCu3Ti4O12additives on electrical properties of (Na,Bi)TiO3-BaTiO3lead free piezoelectric ceramics is discussed.

Structure and Piezoelectric Properties of (1-X)K0.49Na0.51NbO3-XLiTaO3 Lead-Free Piezoceramics

2010 ◽  
Vol 663-665 ◽  
pp. 1310-1313 ◽  
Author(s):  
Yue Ming Li ◽  
Liang Jiang ◽  
Zhong Yang Shen ◽  
Run Hua Liao ◽  
Zhu Mei Wang
Keyword(s):  
Phase Transition ◽  
Room Temperature ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Electromechanical Coupling Coefficient ◽  
Orthorhombic Symmetry ◽  
Coexistence Region ◽  
Solid State Sintering ◽  
Sintering Method

Lead-free (1-x)K0.49Na0.51NbO3-xLiTaO3 (x=0.00-0.07) piezoceramics were fabricated by the conventional solid-state sintering method, the effects of LiTaO3 content on the phase structure and piezoelectric properties of the ceramics were investigated. All the ceramics show single perovskite structure with a phase transition from an orthorhombic symmetry to a tetragonal one across an orthorhombic-tetragonal coexistence region with 0.04<x<0.06. For the ceramic sample with x=0.05, due to the coexistence of orthorhombic and tetragonal phases near room temperature, enhanced piezoelectric constant d33=236 pC/N and planar electromechanical coupling coefficient kp=40.9% are observed. In addition to other good electrical properties such as εr=969, tgδ=0.015 and Qm=41, this ceramic is a promising lead-free piezoelectric material.

Effect of Bi2O3 Addition on the Physical and Electrical Properties of Lead-Free (Na0.5Bi0.5)TiO3-Ba(Sn0.08Ti0.92)O3 Ceramics

2011 ◽  
Vol 415-417 ◽  
pp. 1051-1054
Author(s):  
Chun Huy Wang
Keyword(s):  
Solid Solution ◽  
Coupling Coefficient ◽  
High Frequency ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Coupling Coefficients ◽  
Lead Free Ceramics ◽  
Thickness Mode ◽  
Planar Mode

In the present study, various quantities of Bi2O3were added into 0.98(Na0.5Bi0.5)TiO3-0.02Ba(Sn0.08Ti0.92)O3(0.98NBT-0.02BST) ceramics. High-density samples were obtained through the addition of Bi2O3into 0.98NBT-0.02BST ceramic. It was found that 0.98NBT-0.02BST with the addition of 0~3.0 wt.% Bi2O3exhibit relatively good piezoelectric properties. For 0.98NBT-0.02BST ceramic with the addition of 2 wt.% Bi2O3, the electromechanical coupling coefficients of the planar mode kp and the thickness mode kt reach 0.12 and 0.61, respectively, at the sintering of 1100oC for 3 h. The ratio of thickness coupling coefficient to planar coupling coefficient is 5.1. It is obvious that 0.98NBT-0.02BST solid solution ceramic by adding low quantities of Bi2O3is one of the promising lead-free ceramics for high frequency electromechanical transducer applications.

scholarly journals STRUCTURE, MICROSTRUCTURE, AND PIEZOELECTRIC PROPERTIES OF KNLNS-BNKZ LEAD-FREE CERAMICS UNDER THE EFFECT OF DIFFERENT SINTERING TEMPERATURES

2021 ◽  
Vol 11 (4) ◽  
pp. 25
Author(s):  
Phan Dinh Gio ◽  
Huynh Thi Chi ◽  
Le Tran Uyen Tu ◽  
Nguyen Truong Tho
Keyword(s):  
Electromechanical Coupling ◽  
Piezoelectric Coefficient ◽  
Piezoelectric Properties ◽  
Rhombohedral Phase ◽  
Mixed Phase ◽  
Coupling Coefficients ◽  
Dense Microstructure ◽  
Lead Free Ceramics ◽  
Different Temperatures ◽  
Ceramic Density

Samples of 0.96(K0.48Na0.48Li0.04)(Nb0.95Sb0.05)O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 piezoelectric ceramic were fabricated with conventional ceramic techniques and sintered at different temperatures. The effect of sintering temperature (TS) on the structure, microstructure, and piezoelectric properties of the ceramics was studied in detail. The experimental results showed that with an increase of the TS temperature, the structure of the ceramics transformed from an orthorhombic-tetragonal mixed phase (O-T) at TS £ 1100 °C into a rhombohedral-tetragonal (R-T) mixed phase with a dense microstructure of uniform grain size at TS = 1110 °C. When TS was further increased (TS ³ 1120 °C), the ceramics showed only a rhombohedral phase (R). The ceramics showed the best electrical properties for TS = 1110 °C at which the rhombohedral and tetragonal (R-T) phases coexist. Specifically, the ceramic density reached its highest value (4.22 g/cm3), the electromechanical coupling coefficients kp and kt were 0.46 and 0.50, respectively, and the piezoelectric coefficient d33 was 245 pC/N.

Effect of Bi2O3 Addition on the Microstructure and Electrical Properties of Lead-Free (Na0.5K0.5)NbO3-Ba(Sn0.02Ti0.98)O3 Ceramics

2013 ◽  
Vol 284-287 ◽  
pp. 3-7
Author(s):  
Chun Huy Wang
Keyword(s):  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Piezoelectric Materials ◽  
Dominant Role ◽  
Lead Free ◽  
Coupling Coefficients ◽  
Sintering Process ◽  
Environment Problem ◽  
Lead Free Ceramics

PbZrO3-PbTiO3 (PZT)-based ceramics are playing a dominant role in piezoelectric materials, their evaporation of harmful lead oxide during the sintering process causes a crucial environment problem. It is necessary to search for lead-free piezoelectric materials that have such excellent properties as those found in the PZT-based ceramics. Therefore (Na0.5K0.5)NbO3-based solid solutions were studied to improve piezoelectric properties. In the present study, various quantities of Bi2O3 were added into 0.98(Na0.5K0.5)NbO3-0.02Ba(Sn0.02Ti0.98)O3 (0.98NKN-0.02BST) ceramics. It was found that 0.98NKN-0.02BST with the addition of 0~4.0 wt.% Bi2O3 exhibit relatively good piezoelectric properties. For 0.98NKN-0.02BST ceramic with the addition of 1.0 wt.% Bi2O3, the electromechanical coupling coefficients of the planar mode kp and the thickness mode kt reach 0.21 and 0.46, respectively, at the sintering of 1100oC for 3 h. The ratio of thickness coupling coefficient to planar coupling coefficient is 2.2. It is obvious that 0.98NKN-0.02BST solid solution ceramic by adding low quantities of Bi2O3 is one of the promising lead-free ceramics for high frequency electromechanical transducer applications.

Investigation of Field-Induced Piezoelectric Properties in Pb(Mg1/3Nb2/3)O3-PbTiO3 Ceramics for Transducer Applications

2007 ◽  
Vol 336-338 ◽  
pp. 58-61
Author(s):  
M.H. Lente ◽  
A.L. Zanin ◽  
D. Garcia ◽  
José Antônio Eiras ◽  
L. Leija ◽  
...  
Keyword(s):  
Electric Field ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Ultrasonic Transducer ◽  
Bias Field ◽  
Induced Polarization ◽  
Electromechanical Properties ◽  
Conventional Sintering ◽  
Coupling Factors ◽  
Sintering Method

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.

STRUCTURE AND PIEZOELECTRIC PROPERTIES OF (Bi0.5Na0.5)1-x-y-zBax(Bi0.5Li0.5)ySrzTiO3 LEAD-FREE CERAMICS

2010 ◽  
Vol 03 (01) ◽  
pp. 49-53 ◽  
Author(s):  
DUNMIN LIN ◽  
K. W. KWOK
Keyword(s):  
Crystal Structure ◽  
Remanent Polarization ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
X Ray Diffraction ◽  
Pure Perovskite Structure ◽  
X Ray ◽  
Lead Free Ceramics ◽  
Diffraction Patterns ◽  
Sintering Method

Lead-free ( Bi 0.5 Na 0.5)1-x-y-z Ba x( Bi 0.5 Li 0.5)y Sr z TiO 3 ceramics were prepared by an ordinary sintering method and their structure and piezoelectric properties have been studied. X-ray diffraction patterns show that Ba 2+, Li + and Sr 2+ diffuse into the Bi 0.5 Na 0.5 TiO 3 lattices to form a solid solution with a pure perovskite structure and a morphotropic phase boundary (MPB) between rhombohedral and tetragonal phases is formed at 0.04 ≤ x ≤ 0.08 and z < 0.06. The content of Li + has no obvious influence on the crystal structure of the ceramics. The ceramics situated within the MPB exhibit a lower coercive field E c and a larger remanent polarization P r . Because of the formation of the MPB, lower E c and larger P r , the ceramics with x = 0.06, y = 0.075 - 0.125 and z = 0-0.02 possess improved piezoelectric properties. The optimum d33 (235 pC/N ) and k p (36.3%) are reached at x/y/z = 0.06/0.125/0.02 and 0.06/0.075/0.02, respectively. The deformed P–E loop is also observed near or above T d .

Piezoelectric Properties and Depolarization Temperatures of (Bi1/2Na1/2)TiO3-(Bi1/2K1/2)TiO3-BaTiO3 Lead-Free Piezoelectric Ceramics

2006 ◽  
Vol 320 ◽  
pp. 23-26 ◽  
Author(s):  
Yuji Hiruma ◽  
Kazushige Yoshii ◽  
Rintaro Aoyagi ◽  
Hajime Nagata ◽  
Tadashi Takenaka
Keyword(s):  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Sodium Titanate ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Bismuth Sodium Titanate ◽  
Depolarization Temperature ◽  
Potassium Titanate ◽  
Coupling Factors ◽  
Dielectric And Piezoelectric Properties

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.

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