Influence of barium titanate content and particle size on electromechanical coupling coefficient of lead-free piezoelectric ceramic-Portland cement composites

We establish and analyze an analytical framework by accounting for both the piezoelectric and flexoelectric effects in bimorph cantilevers. The focus is placed on the development of governing electroelastodynamic piezoelectric–flexoelectric equations for the problems of resonant energy harvesting, sensing, and actuation. The coupled governing equations are analyzed to obtain closed-form frequency response expressions via modal analysis. The combined piezoelectric–flexoelectric coupling coefficient expression is identified and its size dependence is explored. Specifically, a typical atomistic value of the flexoelectric constant for barium titanate is employed in the model simulations along with its piezoelectric constant from the existing literature. It is shown that the effective electromechanical coupling of a piezoelectric material, such as barium titanate, is significantly enhanced for thickness levels below 100 nm. The electromechanical coupling coefficient of a barium titanate bimorph cantilever increases from the bulk piezoelectric value of 0.065 to the combined piezoelectric–flexoelectric value exceeding 0.3 toward nanometer thickness level. Electromechanical frequency response functions for resonant power generation and dynamic actuation also capture the size-dependent enhancement of the electromechanical coupling. The analytical framework given here can be used for parameter identification and design of nanoscale cantilevers that can be used as energy harvesters, sensors, and actuators.

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Analysis on the Radial Vibration of Longitudinally Polarized Radial Composite Tubular Transducer

Sensors ◽

10.3390/s20174785 ◽

2020 ◽

Vol 20 (17) ◽

pp. 4785

Author(s):

Xiaoyu Wang ◽

Shuyu Lin

Keyword(s):

High Power ◽

Coupling Coefficient ◽

Piezoelectric Ceramic ◽

Electromechanical Coupling ◽

Electromechanical Coupling Coefficient ◽

Radial Vibration ◽

Resonance Frequencies ◽

Second Mode ◽

Radial Resonance ◽

Effective Electromechanical Coupling Coefficient

The radial vibration of a radial composite tubular transducer with a large radiation range and power capacity is studied. The transducer is composed of a longitudinally polarized piezoelectric ceramic tube and a coaxial outer metal tube. Assuming that the longitudinal length is much larger than the radius, the electromechanical equivalent circuits of the radial vibration of a piezoelectric ceramic long tube and a metal long tube are derived and obtained for the first time following the plane strain theory. As per the condition of the continuous forces and displacements of two contact surfaces, the electromechanical equivalent circuit of the tubular transducer is obtained. The radial resonance/anti-resonance frequency equation and the expression of the effective electromechanical coupling coefficient are obtained. Then, the effects of the radial geometry dimension of the transducer on the vibration characteristics are analyzed. The theoretical resonance frequencies, anti-resonance frequencies, and the effective electromechanical coupling coefficients at the fundamental mode and the second mode are in good agreement with the finite element analysis (FEA) results. The study shows that when the overall size of the transducer is unchanged, as the proportion of piezoelectric ceramic increases, the radial resonance/anti-resonance frequency and the effective electromechanical coupling coefficient of the transducer at the fundamental mode and the second mode have certain characteristics. The radial composite tubular transducer is expected to be used in high-power ultrasonic wastewater treatment, ultrasonic degradation, and underwater acoustics, as well as other high-power ultrasonic fields.

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Piezoelectric and Strain Properties of Strontium-Doped BZT-BCT Lead-Free Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.512-515.1385 ◽

2012 ◽

Vol 512-515 ◽

pp. 1385-1389 ◽

Cited By ~ 6

Author(s):

Wang Feng Bai ◽

Wei Li ◽

Bo Shen ◽

Ji Wei Zhai

Keyword(s):

Coupling Coefficient ◽

Electromechanical Coupling ◽

Piezoelectric Coefficient ◽

Perovskite Phase ◽

Ferroelectric Properties ◽

Lead Free ◽

Electromechanical Coupling Coefficient ◽

Lead Free Ceramics ◽

Pure Perovskite Phase ◽

Free Material

Lead-free piezoelectric ceramics, (Ba0.85-xSrxCa0.15)(Zr0.1Ti0.9)O3 (BSCZT, x=0.01-0.07), were prepared via a solid-state reaction route. The dielectric properties, ferroelectric properties, piezoelectric and strain properties of BSCZT ceramics were studied. The phase structure and microstructure were investigated by X-ray diffraction and scanning electron microscope, respectively. Results showed that dense ceramics with pure perovskite phase were obtained. At room temperature, the samples with x=0.03 exhibited excellent properties with large piezoelectric coefficient d33=534pC/N, planar mode electromechanical coupling coefficient kp=47.7%, thickness mode electromechanical coupling coefficient kt= 42% and high strain levels of 0.34%. In addition, the study of electrical properties suggested that the Curie temperature decreased linearly from 92oc to 73oc with the increasing doping content of strontium in BCZT ceramics. The remnant polarizations, piezoelectric coefficient and strain levels were all increased as the Sr content increased and then decreased with further increased Sr doping level, giving the maximum values at the Sr content of 3mol%. These results indicated that the BSCZT system is a promising lead-free material for applications in the future.

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Research on Electromechanical Properties of Cymbal Piezocomposite Transducer

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.1087 ◽

2005 ◽

Vol 475-479 ◽

pp. 1087-1090

Author(s):

Deng Hua Li ◽

Ke Li ◽

Yang Cheng

Keyword(s):

Electric Field ◽

Transmission Coefficient ◽

Coupling Coefficient ◽

Applied Electric Field ◽

Piezoelectric Ceramic ◽

Electromechanical Coupling ◽

Applied Force ◽

Electromechanical Coupling Coefficient ◽

Electromechanical Properties ◽

Piezoelectric Phase

The electromechanical properties of cymbal piezocomposite transducer were investigated in this paper. Piezoelectric ceramic PZT—5A was used as piezoelectric phase of transducer, and brass foil was used as end cap electrode of cymbal piezocomposite transducer. Several types of this transducer were fabricated. The displacements of this transducer as functions of the applied force and the applied electric field were investigated. It was calculated and analyzed for the energy transmission coefficient and electromechanical coupling coefficient of this transducer which optimum values were obtained.

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Mechanical, dielectric, ferroelectric and piezoelectric properties of 0–3 connectivity lead-free piezoelectric ceramic 0.94Bi0.5Na0.5TiO3–0.06BaTiO3/Portland cement composites

Journal of Materials Science Materials in Electronics ◽

10.1007/s10854-020-05207-4 ◽

2021 ◽

Author(s):

R. Rianyoi ◽

R. Potong ◽

A. Ngamjarurojana ◽

A. Chaipanich

Keyword(s):

Portland Cement ◽

Piezoelectric Ceramic ◽

Piezoelectric Properties ◽

Lead Free ◽

Cement Composites ◽

Ferroelectric And Piezoelectric Properties

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Influence of Base Thickness on Properties of 1-3-2 Connectivity Cement Based Piezoelectric Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.306-307.835 ◽

2011 ◽

Vol 306-307 ◽

pp. 835-838 ◽

Cited By ~ 1

Author(s):

Xin Cheng ◽

Dong Yu Xu ◽

Shuang Shuang Liao ◽

Shi Feng Huang

Keyword(s):

Coupling Coefficient ◽

Electromechanical Coupling ◽

Piezoelectric Composite ◽

Electromechanical Coupling Coefficient ◽

Cement Composites ◽

Base Thickness ◽

Minimum Value ◽

Increasing Trend ◽

Filling Method ◽

Titanate Ceramic

Sulphoaluminate cement and Lead Niobium-Magnesium Zirconate Titanate ceramic (PMN) were used as matrix and functional component to fabricate 1-3-2 piezoelectric ceramic-cement composites by dicing and filling method. The influences of base thickness on piezoelectric, dielectric and electromechanical coupling properties of the composites were analyzed and discussed. The results show that with increasing the base thickness, the piezoelectric stain factor d33 increases gradually, while the piezoelectric voltage factor g33 decreases. The relative dielectric factor εr decreases initially and then increases, while the dielectric loss tan δ increases initially and then decreases. When base thickness is 0.50 mm, εr has the minimum value of 1406. When base thickness is 3.00 mm, tan δ reaches the minimum value of 0.251. With increasing the base thickness, the planar electromechanical coupling coefficient Kp exhibits the decreasing trend, and the thickness electromechanical coupling coefficient Kt and acoustic impedance Z show the increasing trend.

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