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We have extended the calculation procedure to cylindrical samples of anisotropic crystals for RUSpec measurements. The deformation is expressed with Chebyshev polynomials and the Rayleigh-Ritz method is used. We concentrated on anisotropic materials which can be more complicated for the formulation of vibration frequencies. The formulation is angular dependent with cylindrical coordinates. The calculation...
Slow thickness shear vibrations in AT-cut quartz plates driven by a lateral electric field produced by surface electrodes are analyzed theoretically. Mindlin's first-order theory of piezoelectric plates is used. Through an electrically forced vibration analysis, the motional capacitance and mode shapes near resonances are obtained. The effects of the electrode gap, the electrode/plate mass ratio R...
In the design and optimization of quartz crystal resonators, the finite element method has been adopted for the analysis of quartz crystal plates with complications for the vibration frequency and mode shapes. Further extension of such analysis can be made by using complex solutions to extract the electrical parameters of quartz crystal resonators because it is a typical electronic component in circuit...
We analyze the propagation behavior of SH-SAWs in one-dimensional layered periodic magnetoelectric structures which consisting of a thin periodic piezomagnetic/ piezoelectric layer bonded perfectly to the isotropic substrate. The explicit formulations of SH-SAWs dispersion relations in such layered structure with consideration of magnetoelectrically open and shorted cases are derived based on the...
The thickness-shear vibrations of a quartz crystal plate serve as the functioning mode of a resonator with strong couplings to many other modes of vibrations, which can affect the frequency and mode shape, consequently the resonator properties. For applications, it is always desired to have pure thickness-shear vibrations that only exist in an infinite plate. With the three-dimensional equations of...
The aging of quartz crystal resonators has been a key requirement of the product development and broad applications in signal generation and processing of many mission and life critical functions. Among many aging models for the analysis of long-term behavior of quartz crystal resonators, the Arrhenius model is widely accepted for most materials in engineering applications and physical process including...
Quartz crystal resonators of circular type are widely used for frequency control and detection functions with the quartz crystal plate vibrating at the thickness-shear mode. Naturally, vibrations of circular quartz crystal plates are of great interests in the design and optimization of resonators. We have derived the Mindlin plate equations for the thickness-shear vibrations of circular plates in...
It has been discovered that laminate composites of longitudinally magnetized magnetostrictive and transversely poled piezoelectric layers have a giant magneto-electric effect under a low bias magnetic field. The maximum induced magnetoelectric coupling coefficient at resonance is 3.66 V/(cm×Oe), which is over 11 times higher than magnetoelectric coupling coefficient at sub-resonance frequency. The...
The thickness-shear vibration of c-axis tilted 430 ZnO thin film, one side of it is contacted with a layer of viscous conductive liquids is analyzed. The frequency equation has been derived from the three-dimensional linear piezoelectricity theory. The effects of conductivity on the shift in the resonant frequency has been analyzed and discussed in detail. By setting the density, the viscous coefficient...
Cylinders of elastic solids are widely used in various mechanical and electrical structures for many purposes including structural and functional elements. Vibrations of cylinders are of interests for the optimal design and enhanced performance through the consideration of structural and material parameters. By extending earlier work on free vibrations of an elastic cylinder based on the expansion...
For practical applications of quartz crystal resonators, accurate estimation of the aging pattern and adoption of appropriate correction procedure will be important in ensuring the precise operating condition and maintaining their optimal performance. There are two generally accepted aging models for the prediction of long-term behavior of quartz crystal resonators. The Arrhenius model is universally...
In this paper, the electromagnetic energy harvesting scheme by using a Terfenol-D/PZT/Terfenol-D composite magnetoelectric (ME) transducer and a circuit is presented. In the experiments, the electrodes on the piezoelectric layer are connected by a circuit whose impedance is denoted by Z, which is the load impedance. we have analyzed and observed the load dependence of the ME coefficient and the basic...
According to the linear piezoelectric theory, the frequency equation of thickness shear vibration is obtained for investigating the ZnO thin film with a layer of viscoelastic media. Fortunately, some useful results are harvested. From these results, we find that the relative resonant frequency significantly increases when the viscous coefficient is in the range of 0–2Ns/m2. The relation between the...
In this paper, we investigate the characteristics of the Rayleigh surface acoustic waves in one-dimensional layered structures which consisting of a thin isotropic layer bonded perfectly to piezomagnetic/ piezoelectric periodic substrate. The explicit formulations of Rayleigh wave dispersion relations in such layered structure with consideration of magnetoelectrically open and shorted cases are derived...
We study non-axially symmetric vibrations of isotropic, circular plates with free edges. Mindlin's first-order equations governing the coupled thickness-shear, flexural, and thickness-twist modes are obtained for circular plates in cylindrical coordinates by following the derivation of Mindlin plate equations in Cartesian coordinates. The equations are successfully solved by Bessel functions. Numerical...
In this paper, the coupled extension and thickness-twist vibrations are studied for AT-cut quartz plates under Lateral Field Excitation (LFE) with variations along the x1-direction. Mindlin’s two-dimensional equations are used for anisotropic crystal plates. Both free and electrically forced vibrations are considered. Important vibration characteristics are obtained, including dispersion relations,...
We perform a theoretical analysis on electrically forced, coupled thickness-shear, flexural and face-shear vibrations of a rectangular, AT-cut quartz resonator which is electroded in its central part only. Mindlin's first-order theory with the consideration of equivalent viscous dissipation for piezoelectric plates is used, simplified by the assumption of straight-crested waves depending on one spatial...
Among langasite type crystals, La3Ga5.5Ta0.5O14 (LGT) and Ca3TaGa3Si2O14 (CTGS) possess relatively high resistivity (>106Ωcm@600°C) and high effective piezoelectric coefficient (6–8 pC/N) at elevated temperatures, exhibited the potential use for high temperature sensing. In this work, the maximum piezoelectric coefficients and piezoelectric cross-talk behaviors for LGT and CTGS crystals are investigated,...
Mindlin plate theory has been playing a vital role in the analysis of high frequency vibration of quartz crystal resonators, since the coupled equations with infinite number of vibration modes have been truncated to retain essential ones with strong couplings for simplified analysis, and correction factors have been introduced to ensure exact solutions at cut-off frequencies as part of the validation...
High temperature piezoelectric crystals, YCa4O(BO3)3 (YCOB) possess relatively high piezoelectric activities (deff = ∼7.8pC/N, keff= ∼19%) and no phase transition prior to the melting point (∼1500°C), indicating the potential use for high temperature sensing. In this work, growth of YCOB single crystals by using Czochralski (Cz) method was introduced and the temperature dependence of electro-elastic...
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