Electromechanical Properties and Microstructure of Undoped K0.5Na0.5NbO3 Ceramics and KNbO3-NaNbO3 Crystals

2014 ◽  
Vol 90 ◽  
pp. 25-32
Author(s):  
Micka Bah ◽  
Fabien Giovannelli ◽  
Frédéric Schoenstein ◽  
Guy Feuillard ◽  
Emmanuel Le Clezio ◽  
...  
Keyword(s):  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Electromechanical Properties ◽  
Zone Method ◽  
Nitrogen Gas ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Crystal Boule ◽  
Sintering Method

K0.5Na0.5NbO3(KNN) was manufactured by spark plasma sintering (SPS), which is a fast sintering method allowing to control the grain growth. Different samples of KNN are sintered with SPS at 920°C under 50 MPa for 5 minutes. High densities over than 97% are achieved. In order to make domain engineering, KNN crystals are grown by floating zone method. Stable molten zone is reached when oxygen or nitrogen gas flux is used, leading up to 50 mm length of crystals. High electromechanical coupling factor kt about 46 %, kp around 45 % and ε33S/ε0 of 253 are achieved for KNN ceramics poled at optimum electric field about 3 kV / mm. KNN crystal boule exhibits kt about 40 % against 34 % for KNN ceramic, both poled at 1 kV / mm. These results are promising to replace PZT for transducers applications.

Electromechanical Properties of NKN-5LT Multilayer Actuator

2007 ◽  
Vol 26-28 ◽  
pp. 263-266 ◽  
Author(s):  
Min Soo Kim ◽  
Soon Jong Jeong ◽  
Jae Sung Song
Keyword(s):  
Electromechanical Coupling ◽  
Tape Casting ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Electromechanical Properties ◽  
Wide Range ◽  
Conventional Sintering ◽  
Mechanical Transducer ◽  
Multilayer Actuator ◽  
Sintering Method

Li2O excess 0.95(Na0.5K0.5)NbO3-0.05LiTaO3 (NKN-5LT) ceramics were developed by conventional sintering method. Abnormal grain growth in NKN-5LT ceramics was observed with varying Li2O content during sintering. In the 1 mol% Li2O excess NKN-5LT samples sintered at 1000 oC for 4h in air, electromechanical coupling factor and piezoelectric constant of NKN-5LT ceramics were found to reach the highest values of 0.37 and 250 pC/N, respectively. Lead-free piezoelectric of the composition 1 mol% Li2O excess NKN-5LT were fabricated. 10×10×3 mm3 size multilayer ceramic actuators (MLCA) were fabricated by conventional tape casting method. The displacement of the MLCA was ~ 1 μm at 150 V. These results show that the NKN-5LT ceramics with reasonable good piezoelectric properties have the potential to become the next generation material for a wide range of electro-mechanical transducer applications.

Improvement of Electromechanical Coupling Factor and Mechanical Quality Factor in PZT-PMN Ceramics by MnO2 Addition

2009 ◽  
Vol 421-422 ◽  
pp. 381-384
Author(s):  
Rungnapa Tipakontitikul ◽  
Amporn Kamonlert ◽  
Sukum Eitssayeam ◽  
Anuson Niyompan
Keyword(s):  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Mechanical Quality Factor ◽  
Tetragonal Symmetry ◽  
X Ray Diffraction ◽  
Ceramic Structure ◽  
Mechanical Quality ◽  
Conventional Sintering ◽  
Sintering Method

PZT-PMN ceramic system with presence of MnO2 contents were proposed and prepared using conventional sintering method as for piezoelectric transformer application. Phase formation and several dielectric and piezoelectric parameters were studied as a function of MnO2 concentration. The x-ray diffraction study revealed the tetragonal symmetry for all samples with MnO2 doping. To determine polarization, the P-E hysteresis loop were produced and the results indicated that entering of Mn4+ ions in the ceramic structure created large amount of oxygen vacancies and the consequent was observed as displacement of the loops to E axis. The obtained optimum parameter are d33 = 119 pC/N, kp = 0.207, Qm = 1669, tan = 0.0101, Pr = 20 μm/cm2 and Ec = 10 kV/cm.

Structure and Electromechanical Properties of Quenched PMN-PT Single Crystal Thin Films

2006 ◽  
Vol 45 ◽  
pp. 1212-1217 ◽  
Author(s):  
Kiyotaka Wasa ◽  
Isaku Kanno ◽  
Takaaki Suzuki
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Bulk Single Crystal ◽  
Heteroepitaxial Growth ◽  
Electromechanical Properties ◽  
Sputtering Deposition ◽  
Sputtered Films

Thin films of single c-domain/single crystal (1-x)Pb(Mg1/3Nb2/3)O3－xPbTiO3 (PMN-PT), x≅0.33 near a morphotropic boundary (MPB) composition, were heteroepitaxially grown on (110)SRO/(001)Pt/(001)MgO substrates by magnetron sputtering. The heteroepitaxial growth was achieved by rf-magneron sputtering at the substrate temperature of 600oC. After sputtering deposition, the sputtered films were quenched from 600oC to room temperature in atmospheric air. The quenching enhanced the heteroepitaxial growth of the stress reduced single c-domain/single crystal PMN-PT thin films. Their electromechanical coupling factor kt measured by a resonance spectrum method was 45% at resonant frequency of 1.3GHz with phase velocity of 5500 to 6000m/s for the film thickness of 2.3μm. The d33 and d31 were 194pC/N and –104pC/N, respectively. The observed kt , d33 ,and d31were almost the same to the bulk single crystal values.

Lead-Free BSZT/Epoxy 1-3 Composites for Ultrasonic Transducer Applications

2011 ◽  
Vol 254 ◽  
pp. 90-93 ◽  
Author(s):  
Siu To Felix Lee ◽  
Kwok Ho Lam ◽  
Xu Ming Zhang ◽  
Helen L. W. Chan
Keyword(s):  
Biomedical Applications ◽  
Electromechanical Coupling ◽  
Piezoelectric Coefficient ◽  
Ultrasonic Transducer ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Lead Free ◽  
Electromechanical Properties ◽  
Large Bandwidth ◽  
Barium Strontium

With high piezoelectric coefficient (d33> 300 pC/N) and electromechanical coupling factor (kt = 0.45), lead-free barium strontium zirconium titanate ((Ba0.95Sr0.05) (Zr0.05Ti0.95) O3, abbreviated as BSZT)was used to fabricate BSZT/epoxy 1-3 composites with different volume fractions of BSZT ranging from 0.55 - 0.85. The electromechanical properties of the 1-3 composites were determined by the resonance technique. It was found that the theoretical modeling of the 1-3 composites matches quite well with the measured material properties.The 1-3 composite with f = 0.65 was chosen to be fabricated as a transducer due to its comparatively high value of kt. The BSZT/epoxy 1-3 composite transducer demonstrates large bandwidth with good sensitivity, suggesting high potential in biomedical applications.

scholarly journals Microstructure and Piezoelectricity of (Na,K,Li)(Nb,Sb)O3–(Bi,Na)(Sr)ZrO3–BaZrO3 Ceramics

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 868
Author(s):  
Juhyun Yoo ◽  
Jonghyun Lee
Keyword(s):  
Physical Properties ◽  
Piezoelectric Actuator ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Mechanical Quality Factor ◽  
Low Loss ◽  
Mechanical Quality ◽  
Li Substitution ◽  
Sintering Method

In this paper, (Na,K)1−xLi.x(Nb,Sb)O3–(Bi,Na)(Sr)ZrO3–BaZrO3 ceramics were fabricated with x(= Li) substitution by two-step sintering method, and their physical characteristics were investigated. When Li substitution was added to the ceramics, piezoelectric constant (d33) and electromechanical coupling factor (kp) were rapidly reduced. However, mechanical quality factor (Qm) was enhanced. For the KNN-BNZ((K,Na)(Nb)O3–(Bi,Na)(Sr)ZrO3) ceramics with Li(x) = 0 substitution, the best physical properties of d33 = 300 [pC/N], kp = 0.40, Qm = 33 and dialectic constant (εr) = 2430 were shown, respectively. Additionally, the KNN-BNZ ceramics with Li(x) = 0.02, the d33 of 246[pC/N], the kp of 0.37, the Qm of 42 and the εr of 2090 appeared, which were suitable for the low-loss piezoelectric actuator.

scholarly journals Comparison of the effect of argon, hydrogen, and nitrogen gases on the reduced graphene oxide-hydroxyapatite nanocomposites characteristics

BMC Chemistry ◽  
2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Hassan Nosrati ◽  
Rasoul Sarraf-Mamoory ◽  
Arman Karimi Behnagh ◽  
Reza Zolfaghari Emameh ◽  
Amir Aidun ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Initial Pressure ◽  
Constant Concentration ◽  
Nitrogen Gas ◽  
Plasma Sintering ◽  
Reduced Graphene ◽  
Spark Plasma ◽  
Indentation Analysis ◽  
Sintering Method

Abstract In this study, the effect of the argon, nitrogen, and hydrogen gases on the final properties of the reduced graphene oxide- hydroxyapatite nanocomposites synthesized by gas injected hydrothermal method was investigated. Four samples were synthesized, which in the first sample the pressure was controlled by volume change at a constant concentration. In subsequent samples, the pressure inside the autoclave was adjusted by the injecting gases. The initial pressure of the injected gases was 10 bar and the final pressure considered was 25 bar. The synthesized powders were consolidated at 950 °C and 2 MPa by spark plasma sintering method. The final samples were subjected to Vickers indentation analysis. The findings of this study indicate that the injection of argon, hydrogen, and nitrogen gases improved the mechanical properties of the nanocomposites. Injection of gases increased the crystallinity and particle size of hydroxyapatite, and this increase was greater for nitrogen gas than for others. Injection of these gases increased the rate of graphene oxide reduction and in this case the effect of nitrogen gas was greater than the others.

scholarly journals Design and Analysis of a Novel Piezoceramic Stack-based Smart Aggregate

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6438
Author(s):  
Guangtao Lu ◽  
Xin Zhu ◽  
Tao Wang ◽  
Zhiqiang Hao ◽  
Bohai Tan
Keyword(s):  
Resonance Frequency ◽  
Electromechanical Coupling ◽  
Structural Parameters ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Stress Waves ◽  
Parallel Connection ◽  
Smart Aggregate ◽  
In Series ◽  
Piezoelectric Wafers

A novel piezoceramic stack-based smart aggregate (PiSSA) with piezoceramic wafers in series or parallel connection is developed to increase the efficiency and output performance over the conventional smart aggregate with only one piezoelectric patch. Due to the improvement, PiSSA is suitable for situations where the stress waves easily attenuate. In PiSSA, the piezoelectric wafers are electrically connected in series or parallel, and three types of piezoelectric wafers with different electrode patterns are designed for easy connection. Based on the theory of piezo-elasticity, a simplified one-dimensional model is derived to study the electromechanical, transmitting and sensing performance of PiSSAs with the wafers in series and parallel connection, and the model was verified by experiments. The theoretical results reveal that the first resonance frequency of PiSSAs in series and parallel decreases as the number or thickness of the PZT wafers increases, and the first electromechanical coupling factor increases firstly and then decrease gradually as the number or thickness increases. The results also show that both the first resonance frequency and the first electromechanical coupling factor of PiSSA in series and parallel change no more than 0.87% as the Young’s modulus of the epoxy increases from 0.5 to 1.5 times 3.2 GPa, which is helpful for the fabrication of PiSSAs. In addition, the displacement output of PiSSAs in parallel is about 2.18–22.49 times that in series at 1–50 kHz, while the voltage output of PiSSAs in parallel is much less than that in parallel, which indicates that PiSSA in parallel is much more suitable for working as an actuator to excite stress waves and PiSSA in series is suitable for working as a sensor to detect the waves. All the results demonstrate that the connecting type, number and thickness of the PZT wafers should be carefully selected to increase the efficiency and output of PiSSA actuators and sensors. This study contributes to providing a method to investigate the characteristics and optimize the structural parameters of the proposed PiSSAs.

Piezoelectric Shear Mode Inkjet Actuator

2001 ◽  
Vol 687 ◽  
Author(s):  
Jürgen Brünahl ◽  
Alex M. Grishin ◽  
Sergey I. Khartsev ◽  
Carl Österberg
Keyword(s):  
Electromechanical Coupling ◽  
Microelectromechanical Systems ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Shear Mode ◽  
Drop On Demand ◽  
Ink Jet ◽  
Ferroelectric Hysteresis ◽  
Comprehensive Characterization

AbstractWe report on comprehensive characterization of piezoelectric shear mode inkjet actuators micromachined into bulk Pb(Zr0.53Ti0.47)O3 (PZT) ceramics. The paper starts with an overview of different inkjet technologies such as continuous jet and drop-on-demand systems, whereat main attention is turned on piezoelectric systems particularly Xaar-type shear mode inkjet color printheads. They are an example of complex microelectromechanical systems (MEMS) and comprise a ferroelectric array of 128 active ink channels (75νm wide and 360νm deep). Detailed information about manufacturing and principles of operation are given. Several techniques to control manufacturing processes and to characterize properties of the piezoelectric material are described: dielectric spectroscopy to measure dielectric permittivity ε and loss tanσ; ferroelectric hysteresis P-E loop tracing to get remnant polarization Pr and coercive field Ec, and a novel pulsed technique to quantify functional properties of the PZT actuator such as acoustic resonant frequencies and electromechanical coupling factor. Stroboscope technique has been employed to find correlation between the degradation of ink-jet performance and heat/high voltage treatment resulting in ferroelectric fatigue.

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