Accurate determination of material constants of piezoelectric crystal from SAW velocity measurements

Kovacs, G.; Trattnig, G.; Langer, E.

doi:10.1109/ultsym.1988.49381

Cited by 17 publications

(7 citation statements)

References 11 publications

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“…; Π 77 =e −jkβ (7) ·b · C 13 · a (7) (6) ·b · a (6) 3 + β (6) · a (6) 1 ; Π 87 =e −jkβ (7) ·b · a (7) 3 + β (7) · a (7) 1 ; Π 88 =e −jkβ (8) ·b · a The four eigenvalues in the coating layer (n = 1, 2, 3, and 4) are given by:…”

Section: Appendix Matrix Elements Of the Dispersion Relation Of The Smentioning

confidence: 99%

“…In principle, multiparameters can be obtained by such a procedure. For example, Kovacs et al [7] showed that if reasonable initial values of the mass density and the unclamped permittivities are known, then all 13 independent elastic, piezoelectric, and dielectric constants could be obtained with high precision. In most circumstances, however, such a procedure is impractical.…”

Section: Introductionmentioning

confidence: 99%

“…Π 31 =a (1) 1 ; Π 32 = a (2) 1 ; Π 33 = a(3)1 ; Π 34 = a(4) 1 ; −Π 35 =a(5) 1 ; −Π 36 = a(6) 1 ; −Π 37 = a(7) 1 ; −Π 38 = a(8) …”

mentioning

confidence: 99%

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Characterizing unpoled piezoelectric ceramic film by Lamb-waves

Wang

Cheeke

1999

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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Determination of the physical properties of unpoled ceramic films on metallic substrates is considered; the problem is important because these properties may be quite different than those in the bulk, which are caused by the effects of porosity. It is shown that the density and elastic constant C(33) can be determined by a modification of the previously used modal frequency spacing (MFS) method, involving cut-off frequencies for longitudinal and shear sagittal plane modes. This method has the advantage of great simplicity compared with the standard inversion approach. Numerical calculations show that good accuracy of the order of 2% can be obtained for density and for C(33 ) for simulations of PZT films on stainless steel, platinum, and aluminum plates.

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Section: Appendix Matrix Elements Of the Dispersion Relation Of The Smentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Characterizing unpoled piezoelectric ceramic film by Lamb-waves

Wang

Cheeke

1999

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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“…For all five complex piezoelectric constants, a numerical least square method was used to fit the material constants to the complex wave number of a Rayleigh wave measured with a low frequency (200-600 kHz) SAW device [22], [23]. In comparison with electric impedance methods [10], [14], [18], [24], this technique has the advantage that several of the five piezoelectric constants are obtained simultaneously with good accuracy from one measurement [25], [26], and the measurement can be done at multiple frequencies of interest with one PVDF film by simply changing the inter-digital transducer (IDT) period in the SAW device. To check the validity of the bulk wave through-transmission method, the impedance analyzer, and the least square fitting technique, the same techniques were applied to lead zirconate titanate (PZT)-5H, and the results were compared with known values [27].…”

Section: Introductionmentioning

confidence: 99%

Characterization of all the elastic, dielectric, and piezoelectric constants of uniaxially oriented poled PVDF films

Roh

Varadan

2002

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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Polyvinylidene fluoride (PVDF), a piezoelectric material, has many useful applications, for example, as sensors, transducers, and surface acoustic wave (SAW) devices. Models of performance of these devices would be useful engineering tools. However, the benefit of the model is only as accurate as the material properties used in the model. The purpose of this investigation is to measure the elastic, dielectric and piezoelectric properties over a frequency range, including the imaginary part (loss) of these properties. Measurements are difficult because poled material is available as thin films, and not all quantities can be measured in that form. All components of the elastic stiffness, dielectric tensor, and electromechanical coupling tensor are needed in the models. The material studied here is uniaxially oriented poled PVDF that has orthorhombic mm2 symmetry. Presented are the frequency dependence of all nine complex elastic constants, three complex dielectric constants, and five complex piezoelectric constants. The PVDF was produced at Raytheon Research Division, Lexington, MA. Measurements were made on thin films and on stacked, cubical samples. The elastic constants c D 44 and c D 55 , the dielectric constants " T 11 and " T 22 , as well as the piezoelectric constants g15 and g24 reported here have not been published before. The values were determined by ultrasonic measurements using an impedance analyzer and a least square data-fitting technique.

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“…which is approximately half the value of the coiipliiig factor, defines the coupling of an electric excitation i1it.o an elastic deformation [7]. Since the substrate properties are known [8], the unknown properties of the two films can be found [9][10]. A least square fit or experimentally measured group velocity values of t h e t,wo different films to theoretically predicted values yields the unknown elastic constants and the tleiisities of the aluminum and the oxide layer.…”

Section: Results and Measurementsmentioning

confidence: 99%

Determination of elastic constants of thin films for improved CAD modeling of SAW filters and resonators

Ruile

Meier²

IEEE 1992 Ultrasonics Symposium Proceedings

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We have investigated surface acoustic waves propagating in anisotropic and piezoelectric substrates. The m a s and stress-loading effect, caused by two different isotropic and metallic films with finite thickness, is exactly taken into account by analyzing the multilayered structure. The mass density and the elastic stiffness constants of the metallic layers are determined by fitting calculated to measured velocity dispersion curves. High precision group delay time measurements have been made . The thicknesses of the metallic films were measured with a transmission electron microscope (TEM). Finally, a least square fit yields the unknown elastic constants and the densities of the aluminum and the aluminum oxide layer. These improved values of material constants are further used in efficient CAD tools for high performance SAW filter modeling and synthesis.

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Accurate determination of material constants of piezoelectric crystal from SAW velocity measurements

Cited by 17 publications

References 11 publications

Characterizing unpoled piezoelectric ceramic film by Lamb-waves

Characterizing unpoled piezoelectric ceramic film by Lamb-waves

Characterization of all the elastic, dielectric, and piezoelectric constants of uniaxially oriented poled PVDF films

Determination of elastic constants of thin films for improved CAD modeling of SAW filters and resonators

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