PMN PT Research Articles

Characterization of temperature-dependent full-matrix constants of [001]c-poled Mn-doped 28PIN-43PMN-29PT single crystals using one sample

[001]c-poled Mn-doped xPb(In1/2Nb1/2)O3–(1–x–y)Pb(Mg1/3Nb2/3)O3–yPbTiO3 (PIN–PMN–PT:Mn) single crystals (SCs) in the rhombohedral phase possess not only excellent piezoelectric properties but also a high mechanical quality factor, which make them suitable for fabricating high-performance piezoelectric devices. Characterizing the temperature dependence (TD) of full-matrix constants is indispensable for their use in device design. However, there is a significant lack of relevant data. In this study, the TD of the clamped dielectric properties of [001]c-poled 28PIN-43PMN-29PT:Mn SCs was characterized using a dielectric temperature spectroscopy measurement system from 0 to 60 °C. Their elastic and piezoelectric constants were measured using resonant ultrasound spectroscopy in the same temperature range. With an increase in the temperature, all the elastic stiffness constants decreased, whereas all the clamped dielectric constants and the absolute values of all the piezoelectric stress constants increased. The characterization process required only a single sample, which ensured the consistency of the results. Furthermore, the electrical impedance spectra of the sample at 30 and 50 °C were measured and compared with those simulated using the finite-element method with the characterization results. The close agreement between them confirmed the reliability of the characterization results.

Achieving high piezoelectric performance in Pb(Mg1/3Nb2/3)O3–PbTiO3 ferroelectric single crystals through pulse poling technique

To maximize the piezoelectric performance of Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) single crystals, a pulse poling (PP) method is proposed in this study. This study investigates the effects of pulse poling on the piezoelectric and dielectric properties of these PMN–PT single crystals and explores the polarization rotation mechanisms. Our findings indicate a significant improvement in the piezoelectric properties postpulse poling. The optimal PP conditions are identified as 30 pulse numbers at a pulsed electric field of 5 kV/cm. The dielectric constant ɛT33/ɛ0 and piezoelectric coefficient d33 of PMN–0.28PT post PP are 7000–7700 and 2200–2530 pC/N, respectively, representing increases of 49% and 66% compared with those of postdirect current poling (DCP). Additionally, the domain structures of the PMN–0.28PT single crystals after various DCP and PP treatments are examined and compared using piezoelectric force microscopy. The enhanced piezoelectric properties are attributed to the finer domain structures, as well as increased domain wall density achieved through PP. This research introduces a novel domain engineering approach to improve the electromechanical properties of relaxor ferroelectric single crystals.

Ferroelastic strain control of multiple nonvolatile resistance tuning in Cr:In2O3/PMN-PT(111) multiferroic heterostructures

Strain can significantly affect the electronic structure and functional properties of dilute magnetic semiconductors. As a wide bandgap transparent semiconductor, doped In2O3 has also received extensive attention for the modulation of physical properties by lattice strain due to its excellent functional properties. Here, we epitaxially grew the Cr:In2O3 thin film on the (111)-oriented 0.7Pb(Mg1/3Nb2/3)O3–0.3PbTiO3 (PMN–PT) ferroelectric single-crystal substrate. By applying an electric field to PMN–PT, multiple reversible and nonvolatile resistance states can be achieved at room temperature. Utilizing in situ XRD, different strain states corresponding to different resistance states induced by the ferroelastic domain switching of the PMN–PT were characterized. Based on first-principles calculations, the influence of lattice strain on the resistivity of the Cr:In2O3 was discussed. These results offer a route for the design of multiple-valued nonvolatile memory devices and multiple functional magneto-electric devices based on dilute magnetic semiconductors.

Significantly enhanced transmittance and EO property in PMN-PT via optimized two-step pressure-free sintering

It is a great challenge to prepare Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN-PT) ceramics of very high transparency with only oxygen atmosphere pressureless sintering process. To address this issue, this work proposed an optimal low-cost two-step oxygen atmosphere sintering process with a first step at high temperature (T1) for minutes, followed by a second step at lower temperature (T2) for hours without applied pressure. High transmittance of 70 % in the near-infrared wavelength was achieved by our novel two-step process, which far exceeds the performance of PMN–PT ceramics prepared by only oxygen atmosphere sintering process reported in the past and demonstrates comparable performance compared to the costly hot-pressing sintering process. Meanwhile, it shows a high quadratic electro-optic (EO) coefficient of 42.1 × 10−16 m2 V−2, which is meaningful for applications in EO devices. Furthermore, the effect of the temperature difference between the first and second sintering step on the microstructure, transmittance, domain structure, ferroelectric and dielectric property, and polarization switching were discussed. The enhanced transparency is mainly attributed to the higher relative density, and weaker photoluminescence effect with lesser light absorption loss at optimal T1-T2. The improved EO property is due to greater polarization response originating from the interaction of defect dipoles and nanodomains. Such a process should facilitate the cost-effective preparation of other transparent electro-optic materials for practical applications.

Parallel differential evolution paradigm for multilayer electromechanical device optimization

Design optimization of multilayer piezoelectric transducers is intended for efficient and practical usage of wideband transducers for fault diagnosis, biomedical, and underwater applications through adjusting layer thicknesses and volume fraction of piezoelectric material in each layer. In this context, we propose a parallel differential evolution (PDE) algorithm to mitigate the complexities of multivariate optimization as well as the computation time to achieve an optimized wideband transducer for the particular application. For lead magnesium niobate-lead titanate (PMN PT)- and PZT5h-based piezoelectric materials, the fitness function is formulated based on uniformity of mechanical pressure at the first three harmonics to achieve wide bandwidth in the required functional frequency range. It is carried out using a one-dimensional model (ODM), while input layer thicknesses and volume fractions of active material are evaluated using PDE. The simulation is performed on a parallel computing platform utilizing three different host machines to reduce computational time. Results of the proposed methodology for PDE are statistically represented in the form of minimum, maximum, mean, and standard deviation of fitness value, while graphically represented in terms of speedup and time. It can be observed that the execution time for parallel DE decreases with the increasing number of cores.

Sm and Mn doped enhancing the electrical properties of .68PMN–.32PT relaxor ferroelectric thin films

Abstract(1−x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN–PT) has attracted attention due to its excellent electrical properties as a typical relaxor ferroelectric material. High‐quality Mn–Sm co‐doped 0.68PMN–0.32PT thin films were synthesized on the Pt/Ti/SiO2/Si substrates by sol–gel based on spin coating method. The results show that 1 mol% Mn–2 mol% Sm co‐doped PMN–PT thin films have high dielectric constant (εr ∼ 1895) and relatively low dielectric loss (tanδ ∼ .039) at 1 kHz. They also show superior ferroelectric polarization (Pmax ∼ 53.71 μC/cm2, Pr ∼ 30.85 μC/cm2) and high dielectric breakdown strength (∼1656.6 kV/cm), which are primarily due to the low leakage current density (∼10−7 A/cm2). This work suggests a practical approach to enhance the dielectricity, piezoelectricity, and ferroelectricity of PMN–PT thin films.

Phase Transitions under the Electric Field in Ternary Ferroelectric Solid Solutions of Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 near the Morphotropic Phase Boundary: Electric Approach

Temperature–field phase diagrams in the [001]c and [011]c directions in the cubic coordinate in 24%Pb(In1/2Nb1/2)O3–46%Pb(Mg1/3Nb2/3)O3–30%PbTiO3 (24PIN–46PMN–30PT) and 31PIN–43PMN–26PT near the morphotropic phase boundary have been clarified by measuring the temperature dependences of permittivity under an electric field. Field-induced intermediate orthorhombic and tetragonal phases have been newly found in 24PIN–46PMN–30PT and 31PIN–43PMN–26PT, respectively. The temperature dependences of the remanent polarization have also been determined by polarization–electric field (P–E) hysteresis loop evaluation. On the basis of our experimental results, the phase transition and dielectric anisotropy in PIN–PMN–PT have been discussed.

In vivo flexible energy harvesting on porcine heart via highly-piezoelectric PIN–PMN–PT single crystal

One of the main challenges with implantable biomedical devices is the replacement surgeries of depleted batteries for elderly patients. This not only poses medical risks but also results in financial burdens. Consequently, there is a growing need for self-powered in vivo electronics that can convert the biomechanical movements of organs into usable electric energy. Notably, a previously reported in vivo flexible energy harvester generated relatively low current output from a living porcine heart, restricting its ability to operate self-powered electronic devices. In this study, a high current output implantable flexible energy harvester was demonstrated by adopting a highly-piezoelectric single crystal Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) film. The in vivo flexible energy harvester generated a short-circuit output current of 20 µA (corresponding to a current density of 3.08 µA/mm3) from the contraction and relaxation of a porcine heart. This recorded in vivo output current density was attributed to its outstanding piezoelectric charge coefficient of the single crystal PIN-PMN-PT, optimized Ni stressor assisted exfoliation as well as the implementation of a metal-insulator-metal (MIM) structure. Moreover, the flexible energy harvester was also demonstrated as a self-powered cardiac sensor to monitor irregular heartbeats by observing heart rate variations due to drug administration in a porcine heart. Additionally, output performance evaluation was conducted with the chest closed to further assess the feasibility of practical in vivo harvesting. Finally, the single crystal harvester exhibited biocompatibility, showing no signs of cytotoxicity based on cell viability assessments and histological characterizations. These results underscore the potential of the flexible PIN-PMN-PT energy harvesting device as a sustainable power source for self-powered in vivo biomedical electronics.

Domain patterning in nonpolar cut PMN–PT by focused ion beam

The formation of the ferroelectric domain structure as a result of irradiation by focused ion beam of [100]-cut 0.61Pb(Mg[Formula: see text]Nb[Formula: see text]O3–0.39PbTiO3 (PMN–PT) single crystals covered by surface artificial dielectric layer and with free surface was investigated. The dot irradiation resulted in formation of the wedge-like domains grown along [00[Formula: see text]] direction. For irradiation of the free surface, the domains are mainly located under the surface, while at the irradiated surface with an artificial dielectric layer the domains are located at the surface. It was shown that the subsurface wedge-shaped part of the domain is unstable and completely disappears after a month due to spontaneous backswitching under the action of the residual depolarization field. The revealed nonlinear dose dependence of the domain sizes was attributed to the distribution of the electric field using the point charge model. The domain interaction for the distance between irradiated dots below 30[Formula: see text][Formula: see text]m has been revealed in all samples. It was shown that the decrease of the distance between irradiated dots in the created domain row leads to an increase in the length of the central domains, which is explained by the contribution of all injected charges to the switching field.

Investigations on electric properties and domain structures of Nd-doped 0.70Pb(Mg1/3Nb2/3)O3–0.30PbTiO3 relaxor ferroelectric ceramics with high piezoelectric properties

Although rare earth neodymium (Nd) doping is common in Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) single crystals, it is rarely reported in PMN–PT ceramics. To explore the effect of Nd doping on PMN–PT ceramics, PMN–30PT:xNd3+ (x = 0%, 1%, 2%, and 3%) relaxor ferroelectric ceramics were fabricated using a solid-state method via two-step sintering. An enhanced piezoelectric charge coefficient (d33) of ~870 pC/N and a high piezoelectric strain coefficient (d33⁎) of ~1025 pm/V were achieved for x = 2%. Through Rayleigh analysis of polarization–electric field (P–E) hysteresis loops under small electric fields, it was found that the dielectric property was mainly influenced by the intrinsic contribution (local lattice distortion). Furthermore, by investigating domain configurations, high piezoelectric properties were found to be associated with the domain size reduction and local structural heterogeneity. The results indicate that the PMN–30PT:xNd3+ ceramics is a promising material for electronic devices, and that rare earth Nd doping is an efficient strategy for improving the electronic performance of Pb-based relaxor ferroelectrics.

Mechanically induced reversible/irreversible phase transition in PMN–0.3PT single crystal: A phase-field simulation

Relaxor ferroelectric single crystals of Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) have outstanding electromechanical properties in the linear regime. When operated across a phase transition, these properties are significantly enhanced. Understanding the phase transition mechanism under electromechanical external fields is crucial for the new application of PMN–PT that takes advantage of this phase transition. In the present study, the phase transition of PMN–0.3PT single crystals subjected to a mechanical loading/unloading process and the effects of electric field on the phase transition and electromechanical responses of PMN–0.3PT single crystal under coupled mechanical-electrical loading were systematically investigated using a thermodynamics-based phase-field model. The roles the different energy terms play in the evolution of domain and phase structures were assessed. These findings have important implications for both understanding of the phase transition of relaxor ferroelectric single crystal PMN–0.3PT and applications that take advantage of phase transitions in these materials. The model results for the reversible/irreversible phase transition of PMN–0.3PT during the mechanical loading/unloading process are qualitatively consistent with experimental results.

Enhanced piezoelectric and optical properties of tetragonal Sm‐doped Pb(In1/2Nb1/2)–Pb(Mg1/3Nb2/3)–PbTiO3 crystals

AbstractRelaxor ferroelectric single crystal Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) has received extensive research and attention due to its excellent piezoelectric, electromechanical, and other properties. In particular, tetragonal relaxor ferroelectric single crystals have shown greater application potential in high‐temperature devices due to their higher Curie temperature and better stability. However, the low piezoelectric performance of tetragonal crystals also greatly limits its application, and research on its optical properties is not sufficient. In this paper, the tetragonal phase Sm–PIN–PMN–PT single crystal was obtained by the Bridgman method, and its piezoelectric and electro‐optical properties are studied. At the same time, we gave a complete set of piezoelectric, dielectric, and elastic coefficient matrices. The results show that the crystal has excellent piezoelectric and electromechanical properties. The piezoelectric coefficient can reach 905pC/N, the electromechanical coupling coefficient k33 is 85%, and the kt is 72%. The transmittance of the sample polarized along [001] direction can reach 66%. The effective electro‐optical coefficient γc is 60 pm/V at room temperature and can reach 86 pm/V at 70°C. It has a wide operating temperature range and stable performance with frequency variation, which has certain reference significance for application in new electro‐optical devices.

Multicaloric Effect in 0–3-Type MnAs/PMN–PT Composites

The new xMnAs/(1 − x)PMN–PT (x = 0.2, 0.3) multicaloric composites, consisting of the modified PMN–PT-based relaxor-type ferroelectric ceramics and ferromagnetic compound of MnAs were fabricated, and their structure, magnetic, dielectric properties, and caloric effects were studied. Both components of the multicaloric composite have phase transition temperatures around 315 K, and large electrocaloric (~0.27 K at 20 kV/cm) and magnetocaloric (~13 K at 5 T) effects around this temperature were observed. As expected, composite samples exhibit a decrease in magnetocaloric effect (<1.4 K at 4 T) in comparison with an initial MnAs magnetic component (6.7 K at 4 T), but some interesting phenomena associated with magnetoelectric interaction between ferromagnetic and ferroelectric components were observed. Thus, a composite with x = 0.2 exhibits a double maximum in isothermal magnetic entropy changes, while a composite with x = 0.3 demonstrates behavior more similar to MnAs. Based on the results of experiments, the model of the multicaloric effect in an MnAs/PMN–PT composite was developed and different scenario observations of multicaloric response were modeled. In the framework of the proposed model, it was shown that boosting of caloric effect could be achieved by (1) compilation of ferromagnetic and ferroelectric components with large caloric effects in selected mass ratio and phase transition temperature; and (2) choosing of magnetic and electric field coapplying protocol. The 0.3MnAs/0.7PMN–PT composite was concluded to be the optimal multicaloric composite and a phase shift ∆φ = −π/4 between applied manetic fields can provide a synergetic caloric effect at a working point of 316 K.

Achieving combinatory “soft” and “hard” piezoelectric properties in textured ceramics via exploring single‐crystal‐like electrostriction

AbstractDesign of a projecting‐receiving dual‐purpose transducer is challenging due to the difficulty of synthesizing piezoelectric materials with combinatory “soft” properties (high piezoelectric coefficient d) and “hard” properties (low dielectric loss and high mechanical quality factor Qm). In this study, we provide a different perspective to address this challenge via exploiting single‐crystal‐like electrostriction coefficient Q33 through the fabrication of grain oriented or textured “hard” piezoelectric ceramics. Mn‐doped 0.27Pb(In1/2Nb1/2)O3–0.41Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 (Mn:PIN–PMN–PT) piezoelectric ceramics with a high [0 0 1]c texture fraction of 99% were synthesized, which exhibit three times greater piezoelectric properties (d33 ∼ 828 pC/N) than random counterparts (d33 ∼ 251 pC/N), while maintaining low loss (tan δ ∼ 0.5%, Qm = 443). According to the formula , the large improvement of d33 in textured ceramics is mainly due to a doubling increase in dielectric constant ε33 and Q33 (∼0.057 m4/C2). Notably, the Q33 exhibits remarkable similarity to that of PMN–PT single crystals, further contributing to the enhanced piezoelectric performance of textured ceramics. Phase field model of ferroelectrics was performed to understand the texturing on Q33 and elucidate the underlying mechanism at the domain level. The textured ceramics exhibit excellent combinatory “soft” and “hard” properties, which are the promising materials for developing projecting‐receiving dual‐purpose transducers with high efficiency and high sensitivity.

Investigation of the Features of a Superconducting Spin Valve Fe1/Cu/Fe2/Cu/Pb on a Piezoelectric PMN–PT Substrate

The properties of a superconducting spin valve Fe1/Cu/Fe2/Cu/Pb on a piezoelectric PMN–PT substrate ([Pb(Mg1/3Nb2/3)O3]0.7–[PbTiO3]0.3) in electric and magnetic fields have been studied. The magnitude of the shift of the superconducting transition temperature in the magnetic field H = 1 kOe equal to 150 mK was detected, while the full superconducting spin valve effect was demonstrated. Abnormal behavior of the superconducting transition temperature was observed, which manifests itself in the maximum values of the superconducting transition temperature with the orthogonal orientation of the magnetization vectors of ferromagnetic layers. This may indirectly indicate the formation of the easy axis of the magnetization vector of the Fe1-layer adjacent to the piezoelectric substrate PMN–PT. It was found that with an increase in the magnitude of the applied electric field to the PMN–PT substrate, the shift in the superconducting transition temperature of the Fe1/Cu/Fe2/Cu/Pb heterostructure increases. The maximum shift was 10 mK in an electric field of 1 kV/cm. Thus, it has been shown for the first time that a piezoelectric superconducting spin valve can function.

La-doped PMN–PT transparent ceramics with ultra-high electro-optic effect and its application in optical devices

Transparent electro-optic (EO) ceramics of La-doped 0.75Pb(Mg_1/3Nb_2/3)O₃–0.25PbTiO₃ (0.75PMN–0.25PT) were prepared successfully. High transparency of 69% in the near-infrared (IR) wavelength (1550 nm) was achieved at 2 mol% La doping, meanwhile it shows an extremely high quadratic EO coefficient of 45.4×10⁻¹⁶ m²·V⁻², which is indispensable for applications in EO devices. The distribution of a polar nanodomain structure of the samples experiences disorder–order–disorder evolution in a La doping range. It is found that a parallelly-stacked polar nanodomain structure with an easier and faster polarization switching in the 2 mol% La-doped sample suggests that an ordering distribution of polar nanoregions would be critical to inducing large EO effect, transparency, and piezoelectric response. A triple-cavity tunable optical filter (TOF) with a single transmission peak and a tuning voltage below 30 V in a tuning range of 190–197 THz was designed based on our ceramics. The work is believed to bridge the relationship among doping-engineering, EO properties, and polarization behavior, which would guide the further optimization of transparent EO ceramics.

Self-aligned single-electrode actuation of tangential and wineglass modes using PMN-PT

Considering the evolution of rotation sensing and timing applications realized in micro-electro-mechanical systems (MEMS), flexural mode resonant shapes are outperformed by bulk acoustic wave (BAW) counterparts by achieving higher frequencies with both electrostatic and piezoelectric transduction. Within the 1–30 MHz range, which hosts BAW gyroscopes and timing references, piezoelectric and electrostatic MEMS have similar transduction efficiency. Although, when designed intelligently, electrostatic transduction allows self-alignment between electrodes and the resonator for various BAW modes, misalignment is inevitable regarding piezoelectric transduction of BAW modes that require electrode patterning. In this paper transverse piezoelectric actuation of [011] oriented single crystal lead magnesium niobate–lead titanate (PMN–PT) thin film disks are shown to excite the tangential mode and family of elliptical compound resonant modes, utilizing a self-aligned and unpatterned electrode that spans the entire disk surface. The resonant mode coupling is achieved by employing a unique property of [011] PMN–PT, where the in-plane piezoelectric coefficients have opposite signs. Fabricating 1-port disk transducers, RF reflection measurements are performed that demonstrate the compound mode family shapes in the 1–30 MHz range. Independent verification of mode transduction is achieved using in-plane displacement measurements with Polytec’s laser Doppler vibrometer (LDV). While the tangential mode achieves a 40o/s dithering rate at 335 kHz resonant frequency, the n = 2 wine-glass mode achieves 11.46 nm tip displacement at 8.42 MHz resonant frequency on a radius of 60 μm disk resonator in air. A single electrode resonator that can excite both tangential and wine-glass modes with such metrics lays the foundation for a BAW MEMS gyroscope with a built-in primary calibration stage.

Optical Properties of PT‐Based Relaxor Ferroelectric Crystals

AbstractDuring the last two decades, PT‐based relaxor ferroelectric crystals such as (1−x)Pb(Zn1/3Nb2/3)O3–xPbTiO3 (PZN–PT), (1−x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN–PT), and (1−x−y)Pb(In1/2Nb1/2)O3–yPb(Mg1/3Nb2/3)O3–xPbTiO3 (PIN–PMN–PT or PIMNT) crystals, are widely studied due to their huge piezoelectric properties and super‐high electro‐mechanical coupling factors. They have excellent properties with compositions around the morphotropic phase boundary (MPB). It is gratifying that the PT‐based relaxor crystals are replacing traditional PZT piezo‐ceramics in many application fields. Most ferroelectrics with oxygen‐octahedral structure, which show outstanding electro‐mechanical properties, also have excellent optical performances. Ferroelectric single crystals with large electro‐optic (EO) modulation are widely applied in laser communication devices. For the practical applications, the knowledge of detailed optical parameters is desirable. This paper tries to show a global review on the optical properties of PT‐based relaxor ferroelectric crystals. In the present review, optical properties of the crystals are systematically summarized, including refractive index dispersion, transmittance, band gap, EO, acousto‐optic, and photorefractive properties. These properties change with the crystal composition, orientation, and poling condition. The purpose of the review is to provide a resource for the researchers who are concerned with basic physical investigation or optical device applications of the PT‐based relaxor ferroelectric crystals.

Investigation on ferroelectric, dielectric and pressure sensing properties of samarium substituted lead magnesium niobate-lead titanate oxide

In the last several decades, researchers have been developing hydraulic pressure sensors suitable in harsh oil mediums with high figures of merit. A well-known columbite method is used to prepare a series of phase pure electroceramics Pb(1-1.5y)Smy[(Mg1/3Nb2/3)1-xTix]O3 (Sm(y)-PMN(x)PT) with x = 0.20, 0.30; and y = 0.010, 0.025 for possible applications as hydraulic pressure sensors. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were carried out to study the crystal structure, microstructure, and morphology of the sintered ceramics. The frequency and temperature-dependent dielectric and ac conductivity analyses were performed over a temperature range of 300–480 K to understand the phase stability and phase transition temperatures. Room temperature (297 K) polarization-electric field and PUND analysis confirmed the large polarization (∼30–40 μC/cm2) in the investigated compositions. The hydrostatic pressure-dependent relative capacitance change was examined using a lab-made setup for different compositions for the pressure varying from 0 to 50 MPa. The percentage sensitivity varies with samarium and titanium compositions that range from 0.078 MPa−1 to 0.197 MPa−1. The highest relative change in capacitance was obtained for Pb0.963Sm0.025[(Mg1/3Nb2/3)0.80Ti0.20]O3 (Sm0.025-PMN0.20PT) ceramic with percentage sensitivity 0.197 MPa−1, nearly double to our earlier report on Pb[(Mg1/3Nb2/3)0.7Ti0.3]O3 composition. The improvement in sensitivity may be due to inherent properties, such as slim hysteresis, low tangent loss (∼0.002–0.1), large change in phase transition temperature (∼25 K) due to dielectric dispersion and relaxor-like nature compared to other investigated systems.

A vortex-induction underwater energy harvester based on Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystal macro-fiber composites

Various wireless sensors in the Internet of Things (IoT) systems have been adopted in ocean exploration, with increasing energy supply concern. Regarding the marine environment, self-powered sensors utilizing ambient flow and wave energy can increase maintainability with a long lifespan. However, the current underwater piezoelectric energy harvesters made of piezoelectric ceramics suffer from low power density (<0.5 mW cm−3 m−1 s). In this paper, we proposed a vortex-induction underwater piezoelectric energy harvester based on a Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) single crystal macro-fiber composite (MFC). The single crystal MFC shows mechanical flexibility in which the volume fraction of the piezoelectric phase is 70%. Regarding the structure design, a bicylinder configuration with a ladder-shaped cantilever is employed for decreasing the resonant frequency of the underwater piezoelectric energy harvester and enhancing vortex force during fluid–structure interaction process. The designed underwater energy harvester exhibits a high output voltage of 54 Vpp at 0.9 m/s flow in the designed underwater energy harvesting test platform. Due to the high figure-of-merit d 32 × g 32 (7.65 × 10−11 m2/N) of the single crystal, the maximum output power reaches 62 μW under the flow speed of 0.9 m/s. The normalized power density is 1.1 mW cm−3 m−1 s, being 2.3 times larger than that of the state-of-the-art PZT ceramics-based underwater energy harvester. This work will help to mitigate the energy crisis of the IoT system, promoting the development of underwater equipment.