Electromechanical Coupling Factor Research Articles

Effect of epoxy resin and barium zirconate titanate contents on the piezoelectric properties of a 0–3 barium zirconate titanate-Portland cement composite with epoxy resin addition

A 0–3 piezoelectric ceramic-Portland cement (PC) composite with different compositions was fabricated and investigated with the following components: BZT (40, 50, and 60 vol% represented as BZT40, BZT60, and BZT60, respectively) and epoxy resin (0, 3, 5, and 7 vol% represented as ER0, ER3, ER5, and ER7, respectively). Experimental results show that increasing ER content (0–7 vol%) led to an increase in density (ρc), for 50% BZT increased from 3.42 to 3.55 g/cm3 and a decrease in porosity, from 12.71 to 11.67% (for 50%BZT) and acoustic impedance (Zc) value increased from 9.67 to 8.84 × 106 kg/m·s2. Both εr and tanδ decreased with increasing ER content. ER as the third phase resulted in a lower leakage current and the BZT60ER7 composite is found to have the lowest leakage current (20 μA). Increasing ER content led to a decrease in the piezoelectric charge coefficient (d33). However, a notable increase in piezoelectric voltage coefficient (g33) with increasing ER content up to 3 vol% was found. The optimization of both Zc and g33 in this study can be observed in BZT50ER3 composite (Zc = 9.16 × 106 kg/m2·s and g33 = 13.9 × 10−3 V m/N). In addition, the highest planar electromechanical coupling factor (kp = 17.97%) and thickness electromechanical coupling factor (kt = 17.75%) can be observed in BZT60ER7 composite.

Structural, dielectric and piezoelectric characterization of BFN-modified PZT-based (MPB) ceramics

ABSTRACT The solid solution of xBi(Fe1/3Nb2/3)O3–(1-x)Pb(Zr0.50Ti0.50)O3 ceramics near morphotropic phase boundary (MPB) (BFN–PZT, x = 0, 0.0025, 0.005, 0.0075, 0.01) were prepared by conventional solid-state reaction method. The samples added with different Bi2O3, Fe2O3, Nb2O5 contents were compared in terms of the phase structure, microstructure, dielectric properties, and piezoelectric properties. In particular, rhombohedral-tetragonal morphotropic phase boundary was observed in BFN–PZT crystal structure near the composition of x = 0.005. The BFN–PZT ceramics exhibited the following optimal properties at x = 0.005: dielectric constant ϵr of 847, dielectric loss tanδ of 0.034, Curie temperature TC of 390°C, electrical conductivity σ of 0.441 (Mohm.m)−1, piezoelectric charge constant d33 of 416 pC/N, electromechanical coupling factor KP of 0.654, and mechanical quality factor Qm of 426, making it a promising material for use in high-intensity ultrasound applications.

Magneto-Mechano-Electric generator of lead-free piezoelectric Ba0.95Ca0.05Ti0.95Zr0.025Sn0.025O3 / Co0.8Ni0.2Fe2O4 magnetostrictive multiferroic laminate structure

We report the magneto-mechano-electric (MME) response of (2–2) layered magnetostrictive-piezoelectric composite structures of Co0.8Ni0.2Fe2O4 / Ba0.95Ca0.05Ti0.95Zr0.025Sn0.025O3 / Co0.8Ni0.2Fe2O4 (CNFO/BCTZS/CNFO) ceramics. The basic magnetic and electric properties to support the multiferroism nature were studied and discussed. The BCTZS piezoceramics showed a piezoelectric charge coefficient of (d33) ∼ 149 pC/N, piezoelectric voltage coefficient of (g33) ∼ 7.64 × 10-3 (Vm/N) and planar electromechanical coupling factor of (kp) ∼ 26 % with additional benefits of phase coexistence of orthorhombic-tetragonal lattice symmetries near room temperature. The CNFO magnetostrictive phase reveals a piezomagnetic coefficient (q11 = dλ11/dH) of − 0.0625 ppm/Oe at a lower magnetic field bias of 600 Oe. The MME response of CNFO/BCTZS/CNFO multiferroics is validated by measuring the magnetoelectric (ME) coefficient αME in longitudinal–transverse (L-T) mode. The CNFO/BCTZS/CNFO structure revealed the αME of 50.8 mV/cm·Oe at a field of 644 Oe at off-resonance frequency i.e. 1 kHz. The frequency-dependent αME measurements at two different constants (Hdc), i.e. 100 Oe and 600 Oe showed the resonant enhancement in ME coupling at 8.5 kHz by attaining the peak value of magnetoelectric coefficient αME ∼ 0.27 V/cm·Oe and 0.107 V/cm·Oe respectively. Consequently, it is confirmed that due to the electromechanical resonance effect, the magnitude of αME is increased by six times as that measured at off-resonance i.e. 1 kHz. Therefore, the present multiferroic 2–2 structures are suitable for magneto-mechano-electric (MME) energy harvesters as well as magnetic field sensor applications.

Design and Fabrication of a Flexible Gravimetric Sensor Based on a Thin-Film Bulk Acoustic Wave Resonator.

Sensing systems are becoming less and less invasive. In this context, flexible materials offer new opportunities that are impossible to achieve with bulky and rigid chips. Standard silicon sensors cannot be adapted to curved shapes and are susceptible to big deformations, thus discouraging their use in wearable applications. Another step forward toward minimising the impacts of the sensors can be to avoid the use of cables and connectors by exploiting wireless transmissions at ultra-high frequencies (UHFs). Thin-film bulk acoustic wave resonators (FBARs) represent the most promising choice among all of the piezoelectric microelectromechanical system (MEMS) resonators for the climbing of radio frequencies. Accordingly, the fabrication of FBARs on flexible and wearable substrates represents a strategic step toward obtaining a new generation of highly sensitive wireless sensors. In this work, we propose the design and fabrication of a flexible gravimetric sensor based on an FBAR on a polymeric substrate. The resonator presents one of the highest electromechanical coupling factors in the category of flexible AlN-based FBARs, equal to 6%. Moreover, thanks to the polymeric support layer, the presence of membranes can be avoided, which leads to a faster and cheaper fabrication process and higher robustness of the structure. The mass sensitivity of the device was evaluated, obtaining a promising value of 23.31 ppm/pg. We strongly believe that these results can pave the way to a new class of wearable MEMS sensors that exploit ultra-high-frequency (UHF) transmissions.

Improved chemical defects, domain structure and electrical properties of BiFeO3–BaTiO3 lead-free ceramics by simultaneous Na/Bi codoping and quenching process

Lead-free piezoelectric 0.7BiFeO3-0.3Ba1-x(Bi0.5Na0.5)xTiO3 (BF–B(BN)xT, 0.00 ≤ x ≤ 0.02) ceramics were synthesized with a solid-state reaction method utilizing modified air quenching. The impacts of Na/Bi codoping and air quenching on the structure, defects, and electrical properties of BF–B(BN)xT were investigated. Each sample exhibited a pure perovskite structure with rhombohedral (R) and pseudocubic (pC) phase coexistence. The insulation and piezoelectric properties were improved by appropriate Na/Bi codoping. Due to the enhanced lattice distortion and long parallel strip domains induced by the quenching treatment, excellent piezoelectric performance d33 = 196 pC/N and a high Curie temperature Tc = 498 °C were obtained for the quenched BF–B(BN)0.015T ceramic. In addition, in situ measurements of the electromechanical coupling factor (kp) and thermal depolarization studies demonstrated that quenching treatment improved the stability of high-temperature piezoelectric properties, and the d33 of the quenched BF–B(BN)0.015T ceramic remained at 183 pC/N at 400 °C, indicating good potential in high-temperature applications.

Structural and electrical properties of potassium and neodymium substituted SrBi4Ti4O15 ceramics

Sr1-2xKxNdxBi4Ti4O15 (x = 0.0 and 0.1) ceramics are synthesized by solid-state sintering method. The phase formation confirmation and structural parameters are obtained from X-ray diffraction analysis. The effect of potassium and Neodymium substitution on microstructure, dielectric and piezoelectric properties of ceramics are investigated. The Curie temperature is found to be decreased and the piezoelectric coefficient (d33), electromechanical coupling factor (kp) are found to be increased.

Fabrication of a New Air-Gap FBAR on an Organic Sacrificial Layer through an Innovative Design Algorithm

Realizing thin-film acoustic wave resonators presents many design and fabrication challenges. Actual material specifications always differ from nominal material properties employed in simulations, as they depend on the deposition technique and parameters used and on equipment type and status. Moreover, each deposition process introduces a degree of uncertainty regarding the thicknesses of the layers. All these factors have a substantial impact on the resonance frequency, which often differs from the designed value. This work details the design and fabrication of an aluminum nitride (AlN)-based thin-Film Bulk Acoustic wave Resonator (FBAR) showing one of the highest products of Q-factor and electromechanical coupling of 6895. The design process is based on an innovative, fast, and scalable design and fabrication approach that considers fabrication tolerances. The algorithm returns very fast results on the order of seconds, and successfully estimates the resonance of a designed stack at 2.55 GHz with a very low error of 0.005 GHz (about 0.2%). The FBAR layer stack is suspended on a polymeric membrane and an innovative rapid dissolving sacrificial layer made of Lift-Off Resist (LOR). This new fabrication protocol obtains resonators with an electromechanical coupling factor of 4.7% and a maximum quality factor of 1467, respectively.

Multi-Parametric Exploration of a Selection of Piezoceramic Materials for Bone Graft Substitute Applications.

This work was devoted to the first multi-parametric unitary comparative analysis of a selection of sintered piezoceramic materials synthesised by solid-state reactions, aiming to delineate the most promising biocompatible piezoelectric material, to be further implemented into macro-porous ceramic scaffolds fabricated by 3D printing technologies. The piezoceramics under scrutiny were: KNbO3, LiNbO3, LiTaO3, BaTiO3, Zr-doped BaTiO3, and the (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 solid solution (BCTZ). The XRD analysis revealed the high crystallinity of all sintered ceramics, while the best densification was achieved for the BaTiO3-based materials via conventional sintering. Conjunctively, BCTZ yielded the best combination of functional properties-piezoelectric response (in terms of longitudinal piezoelectric constant and planar electromechanical coupling factor) and mechanical and in vitro osteoblast cell compatibility. The selected piezoceramic was further used as a base material for the robocasting fabrication of 3D macro-porous scaffolds (porosity of ~50%), which yielded a promising compressive strength of ~20 MPa (higher than that of trabecular bone), excellent cell colonization capability, and noteworthy cytocompatibility in osteoblast cell cultures, analogous to the biological control. Thereby, good prospects for the possible development of a new generation of synthetic bone graft substitutes endowed with the piezoelectric effect as a stimulus for the enhancement of osteogenic capacity were settled.

Gradation and porosity’s effect on Love waves in a composite structure of piezoelectric layers and functionally graded porous piezoelectric material

Love waves propagation in a composite structure lying over an elastic half-space are studied. The composite structure contains n piezoelectric layers and a functionally graded porous piezoelectric material(FGPPM) layer. The linear and exponential gradation of mechanical and electrical properties of the FGPPM layer are considered. The WKB technique is applied for obtaining the solution of the equations in the FGPPM layer. The transfer matrix is obtained for multilayers of piezoelectric materials. The frequency equations for both electrically open and short boundaries have been obtained. Numerical computations have been done to solve the frequency equations and to obtain electromechanical coupling, stress and displacements. The effect of porosity, wavenumber and gradation on the phase velocity and group velocity of Love waves have been studied and observed that group velocity is more affected by porosity than the phase velocity. Better resolution without compromising the magnitude of surface wave velocity seems to be achievable for piezoceramic having 20% to 30% porosity. Apart from these, the variations of attenuation and electromechanical coupling factor with grading parameters and porosity have also been examined and noticed that the grading type has a considerable effect on the coupling factor and attenuation quality factor. A relative study is conducted to demonstrate the impact of the number of piezoelectric layers above the FGPPM layer on dispersion curves and it is found that more energy is trapped with layering in a stack and an initial increase in the number of layers in the stack of composites is more effective. The effects of porosity and wavenumber on mechanical displacement, electrical displacement and stress have been studied numerically. Also, lateral and vertical variations of the mechanical displacement, electrical displacement and stress have been studied. The findings of the study are expected of use in improving the efficiency of SAW devices.

Lead-free bimetallic oxide loaded on reduced graphene oxide‒poly(dopamine) hybrid nanocomposite with enhanced crystallinity and piezoelectric performance

The increased demand for electricity with low environmental impact has prompted researchers to find solutions to obtain the maximum output. This effort has imparted a significant focus on piezoelectric materials owing to their high piezoelectric coefficient and electromechanical coupling factor. In this study, reduced graphene oxide encapsulated with polydopamine and incorporated with zinc manganate hybrid nanocomposite (rGO‒pDA‒ZnMnO 3 HNC) was prepared. The as-prepared HNC, of different weight percentages, was blended with 15 wt% poly(vinylidene fluoride) (PVDF) to form different PVDF@rGO‒pDA‒ZnMnO 3(R) thin films. Subsequently, the flexible piezoelectric sensors (FPSs) were fabricated by a solution-casting method. The as-prepared HNC and thin films were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The PXRD data revealed the increased degree of crystallinity of the thin films from 54% to 68% with the increase in filler loading. The β-phase of PVDF also increased, as obtained from the FT-IR analysis. Electrical characterization of the prepared FPSs was carried out by estimating the sensitivity of the devices on different loads. The acquired response at a force of 1 N for PVDF@rGO‒pDA‒ZnMnO 3(0.2 wt%) improved by 44% than that of PVDF@rGO‒pDA‒ZnMnO 3(0 wt%) . The force applied by the finger on the device also generated voltages, which were used to charge the capacitor, thereby used to glow the light-emitting diodes with amplifications. These promising results demonstrate the potential for developing lead-free efficient piezoelectric nanogenerators for energy-harvesting applications and self-powered devices.

An easy approach to obtain high piezoelectric properties in hard PZT sintered at 950 °C

A hard Pb(Zr,Ti)O 3 (PZT), which has a high electromechanical coupling factor, is used in various piezoelectric devices. However, the sintering temperature of this material is high, approximately 1100–1200 °C, restricting the usage of cheap base metal electrodes in fabrication of multi-layer components. This study shows an easy approach for a hard PZT not only to be sintered at ≤950 °C but also to have excellent piezoelectric properties. For the readers interested in the low-temperature sintering study of a PZT ceramic, it is described how the PZT compositions and additives are selected and how the experiments can be simplified in this manuscript. Consequently, 0.8 Pb(Zr 0.475 Ti 0.525 )O 3 –0.2 Pb[(Mg 0.5 Ni 0.5 ) 1/3 Nb 2/3 ]O 3 + 0.5 wt% MnO 2 + 0.1 wt% Li 2 CO 3 + 0.2 wt% Fe 2 O 3 (sintered at 950 °C) shows a high k p of 0.62, an excellent mechanical quality factor ( Q m ) of 1,976, and a piezoelectric constant ( d 33 ) of 350 pC/N.

The Effect of Nb2O5 Precursor on KNN-Based Ceramics’ Piezoelectricity and Strain Temperature Stability

The performance of potassium sodium niobate ((K, Na) NbO3, KNN)-based lead-free piezoelectric ceramics has significantly improved over the past decade. However, the performance bottlenecks of KNN-based ceramics cannot be ignored. Here, the Nb2O5 precursor is obtained after thermal pretreatment, which can evidently improve the piezoelectric properties and strain temperature stability of KNN-based ceramics. With the help of the Nb2O5 precursor treated at 800 °C, the optimal piezoelectric constant d33 of 303 pC/N, inverse piezoelectric constant d*33 of 378 pm/V, Curie temperature TC of 310 °C and electromechanical coupling factor kp of 42% are obtained, and the value of d33 improves by about 30% compared with that of the ceramic prepared with untreated Nb2O5 as raw material. Additionally, in comparison with the strain temperature stability of the ceramics prepared with untreated Nb2O5 as raw material, the temperature stability is enhanced. Therefore, this study provides a useful approach to break the existing performance bottleneck and further improve the properties of KNN-based ceramics.

Ultra-wide band and improved quality factor SH-type SAW devices by employing Mn-doped Pb(In1/2Nb1/2)O3– Pb(Mg1/3Nb2/3)O3–PbTiO3 thin film/diamond layered structure

This paper presents a piezoelectric layered structure composed of Mn-doped PIN-PMN-PT thin film combined with diamond for high electromechanical coupling factor (K2) and improved quality factor (Q) SAW devices. Comprehensive theoretical analysis of SAW resonator on the proposed structure is performed to calculate its SAW characteristics including K2, V (phase velocity) and Q. The influence of the Euler angle, Mn-doped PIN-PMN-PT layer's thickness and the electrode's thickness as well as electrode's materials on the SAW properties are investigated. It is shown that the maximum electromechanical coupling factor of the proposed structure has been theoretically shown up to be 79.5 % for the main mode called shear-horizontal (SH)-type SAW. The FOM(K2·Q) is enhanced to 868.5, which is more than two times larger than that of the previously reported work using pure PIN-PMN-PT. Such enhancement of FOM makes such structure has great potential application in ultra-wide band and high Q SAW filters operating at 1GHz–3GHz.

Tiny Piezoelectric Multi-Layered Actuators with Application in a Compact Camera Module-Design, Fabrication, Assembling and Testing Issues.

Piezoelectric actuators with multi-layer structures have largely gained attention from academic and industry experts. This is due to its distinctive advantages of fast response time, huge generative force and the inherent good planar electromechanical coupling factor, as well as other mechanical qualities. Typically, lead zirconate titanate (PZT) is one of the most represented piezoelectric ceramic materials that have been used for multi-layer piezoelectric actuators. Piezoelectric multi-layered actuators (PMLAs) were developed vigorously in the past decades due to the emergence of portable devices, such as smartphones with a highly compact camera module (CCM) and an image stabilizer (IS). This study reviewed the progress made in the field of PMLA applications, with a particular focus on the miniaturized dimensions and associated generated output force, speed and maximum output power requirement for various loads. Several commercial attempts, such as Helimorph, Lobster and the two-degrees-of-freedom ultrasonic motor (USM), were investigated. The proposed simple bimorph and multi-layer bimorph USMs experimentally showed thrust as high as 3.08 N and 2.57 N with good free speed and structural thicknesses of 0.7 and 0.6 mm, respectively. When compared with the other 14 reported linear USMs, they ranked as the top 1 and 2 in terms of the thrust-to-volume ratio. The proposed design shows great potential for cellphone camera module application, especially in moving sensor image stabilization. This study also provided outlooks for future developments for piezoelectric materials, configurations, fabrication and applications.

Modeling and characterization of thick piezoelectric disk including radial, longitudinal and shear modes

The article deals with the complete modeling and characterization of thick piezoelectric ceramics. Modeling is based on radial and longitudinal mode determination of a thick piezoelectric disk. Shear modes are inserted in the modeling using the properties of partial derivatives. Displacements calculation of the three vibration modes leads to the determination of the general impedance of a thick disk. Modeling leads to new electromechanical coupling factors (EMC factors) showing the influence of coupling between: longitudinal-radial, longitudinal-shear and also shear-longitudinal modes. Using one-dimension hypotheses, longitudinal and radial 3D-EMC factors reduce to the well-known EMC factors defined by Standards. EMC factors related to coupling between longitudinal and shear modes are new. Complete characterization of the piezoelectric ceramic disk has been carried out for calculating all the constant-E and constant-D elastic constant (2 × 6) and the three piezoelectric coefficients related to the disk. Calculated elastic constant matrix is consistent because it does not depend on compliances.

Inch-Size Molecular Ferroelectric Crystal with a Large Electromechanical Coupling Factor on Par with Barium Titanate.

Molecular ferroelectrics with large piezoelectric responses have long been sought for their advantages of light weight, mechanical flexibility, and easy preparation, in contrast to the widely used inorganic counterparts. Representatively, a molecular ferroelectric crystal [Me3NCH2Cl]CdCl3 (TMCM-CdCl3) has been found to show a large piezoelectric coefficient d33 of 220 pC/N exceeding that of BaTiO3 (You et al. Science2017, 357, 306-309). However, although the d33 of molecular ferroelectrics has achieved great progress, their electromechanical coupling factor k33, which is essential for various piezoelectric applications, including ultrasonic transducers and actuators, was rarely explored and is far below the level of inorganic ferroelectrics. The major reason for this situation is the great challenge of growing large-size crystals which is a key limiting factor for measuring k33. Here, we grew inch-size crystals of organic-inorganic perovskite ferroelectric TMCM-CdCl3 with a high d33 (383 pC/N) for investigating its piezoelectric responses including the k33 (0.483) by the resonance method. Such high k33 (0.483) is much larger than those of other molecular ferroelectrics and competitive with that of BaTiO3 (0.5). In addition, TMCM-CdCl3 has a low elastic modulus of 13.03 GPa, an order of magnitude lower than that of BaTiO3. This finding sheds light on the exploration of large electromechanical coupling factors in molecular ferroelectrics for potential applications in flexible and portable piezoelectric devices.

Water Quenched and Acceptor-Doped Textured Piezoelectric Ceramics for Off-Resonance and On-Resonance Devices.

Piezoelectric materials should simultaneously possess the soft properties (high piezoelectric coefficient, d33 ; high voltage coefficient, g33 ; high electromechanical coupling factor, k) and hard properties (high mechanical quality factor, Qm ; low dielectric loss, tan δ) along with wide operation temperature (e.g., high rhombohedral-tetragonal phase transition temperature Tr-t ) for covering off-resonance (figure of merit (FOM), d33 × g33 ) and on-resonance (FOM, Qm × k2 ) applications. However, achieving hard and soft piezoelectric properties simultaneously along with high transition temperature is quite challenging since these properties are inversely related to each other. Here, through a synergistic design strategy of combining composition/phase selection, crystallographic texturing, defect engineering, and water quenching technique, <001> textured 2mol% MnO2 doped 0.19PIN-0.445PSN-0.365PT ceramics exhibiting giant FOM values of Qm × (227-261) along with high d33 × g33 (28-35 × 10-12 m2 N-1 ), low tan δ (0.3-0.39%) and high Tr-t of 140-190°C, which is far beyond the performance of the state-of-the-art piezoelectric materials, are fabricated. Further, a novel water quenching (WQ) room temperature poling technique, which results in enhanced piezoelectricity of textured MnO2 doped PIN-PSN-PT ceramics, is reported. Based upon the experiments and phase-field modeling, the enhanced piezoelectricity is explained in terms of the quenching-induced rhombohedral phase formation. These findings will have tremendous impact on development of high performance off-resonance and on-resonance piezoelectric devices with high stability.

Response of piezoelectric lead zirconate titanate to 20 MeV electron beam irradiation

The response of the lead zirconate titanate (PZT) element to an irradiated 20 MeV electron beam was studied. Both the resonant and antiresonant frequencies of the PZT element were measured under irradiation, and then the variation of the electromechanical coupling factor was investigated. It was found that the coupling factor linearly decreased with increasing beam energy absorbed in the PZT element, whereas the surface temperature remained constant. We propose a dosimeter based on piezoelectric PZT.

Utilization of Nonstoichiometric Nb5+ to Optimize Comprehensive Electrical Properties of KNN-Based Ceramics.

An easy approach is suggested to obtain excellent piezoelectric performances in potassium sodium niobate (KNN)-based ceramics simultaneously with low dielectric loss (tanδ), high Curie temperature (TC), and electromechanical coupling factor (kp). Herein, a KNN-based ceramics system with nonstoichiometric Nb5+ is designed. Excessive Nb5+ occupying the B-site significantly influences the microstructural features and electrical properties of KNN-based ceramics. Furthermore, the excessive Nb5+ improves the temperature stability of ceramics by providing the domain wall pegging effect and defect dipole. A high TC = 300 °C, large kp = 0.516, and d33 = 450 pC/N can be simultaneously obtained in the KNN-based ceramics with nonstoichiometric Nb5+. These results confirm that the comprehensive electrical properties of KNN-based ceramics can be tuned by optimizing the content of nonstoichiometric Nb5+.

Rayleigh waves in nonpolar Al0.7Sc0.3N(112¯0) films with enhanced electromechanical coupling and quality factor

This work reports on the growth of 1 µm nonpolar a-plane Al0.7Sc0.3N(112¯0) thin films on an r-plane sapphire Al2O3(11¯02) via magnetron sputter epitaxy. The electro-acoustic properties of the film structures were characterized using surface acoustic wave (SAW) resonators. Measured electrical responses were found to be strongly anisotropic in terms of the wave propagation direction. We identified a sagittal polarized Rayleigh wave mode with large coupling (keff2= 3.7%), increased phase velocity (v= 4825 m/s), as well as high quality factor (Q &amp;gt; 1000) for SAW propagation along the c-axis [0001] and normalized thicknesses h/λ=0.2. Finite element method simulations using electro-acoustic properties of Al0.7Sc0.3N obtained from the density functional theory reproduce our experimental results.