High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,inclu...High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments.展开更多
Pb(Mn_(1/3)Sb_(2/3))x(Zn_(1/3)Nb_(2/3))y(Zr_(0.535)Ti_(0.465)),_(1-x-y)O_(3)(PMZN)piezoelectric ceramics were fabricated,The effects of sintering temperature and heat-treatment time on properties wen discussed,the opt...Pb(Mn_(1/3)Sb_(2/3))x(Zn_(1/3)Nb_(2/3))y(Zr_(0.535)Ti_(0.465)),_(1-x-y)O_(3)(PMZN)piezoelectric ceramics were fabricated,The effects of sintering temperature and heat-treatment time on properties wen discussed,the optimum preparation technology parameters were obtained.In this case,the ceramics have the highest electromechanical coupling coefficients and mechanical quality factor and the least dielectric loss.It is revealed that the PMZN piezo-ceramics material can be utilized for high-power ultrasound transducers.展开更多
This paper studies the relaxation processes and electromechanical hysteresis in relaxor piezoceramics based on the PzT system.Measurements and analysis of the electric displacement and mechanical strain hysteresis loo...This paper studies the relaxation processes and electromechanical hysteresis in relaxor piezoceramics based on the PzT system.Measurements and analysis of the electric displacement and mechanical strain hysteresis loops recorded in bipolar AC electric fields in the frequency range 0.001-5 Hz were performed by means of the electromechanical response characterization system(STEPHV)and program(STEP).It was found that the coercive field,remnant and saturation electric displacement,area of hysteresis loops and relative mechanical strain values are strongly dependent on frequency.As a result of this study,complete sets of parameters characterizing the switching and ferroelectric hysteresis processes in relaxor piezoceramics were obtained.展开更多
This study investigates the relationship between the electro-mechanical properties of Cu-doped potassium sodium niobate(KNN)piezoceramics driven at high vibration velocities and their structural origins.Intrinsic and ...This study investigates the relationship between the electro-mechanical properties of Cu-doped potassium sodium niobate(KNN)piezoceramics driven at high vibration velocities and their structural origins.Intrinsic and extrinsic contributions to the dynamic strain were quantified at high-power resonance conditions by in-situ high-energy X-ray diffraction.These contributions were correlated to the observed sub-coercive dielectric and piezoelectric responses.Cu doping impairs extrinsic contributions of KNN due to the movement of none180°domains,akin to acceptor-doped hard PZT,reducing the fraction of transverse strain originating from none180°domain wall motion over the total strain of 5%at 0.8 m/s.Therefore,the performance of Cu-doped KNN and PZT were found to be comparable.Both systems exhibit a high mechanical quality factor at low vibration velocity,which decreases at high displacement rates.Additionally,the temperature dependence of electromechanical properties for different Cu doping amounts was investigated.In particular,the mechanical quality factor at the vibration velocity of 1 m/s in a temperature range of-40℃to 140℃was studied.According to thefindings,the composition doped with 0.5%Cu exhibited a stable vibration at 1 m/s,with only 10%variation in the mechanical quality factor between 20C and 140℃.展开更多
In this paper,we present the experimental results of the comprehensive study of the microstructural features and complex dielectric,elastic and electromechanical properties of the ferroelectrically“hard”piezoceramic...In this paper,we present the experimental results of the comprehensive study of the microstructural features and complex dielectric,elastic and electromechanical properties of the ferroelectrically“hard”piezoceramics based on the lead zirconate titanate(PZT)composition.For the measurements and analysis of the real and imaginary parts of the complex parameters of the studied piezoceramics as well as their frequency dependences,we used precision impedance analyzer Agilent 4294A and Piezoelectric Resonance Analysis Program(PRAP)software.We have found that the studied piezoceramics demonstrate a unique combination of dielectric,elastic and electromechanical parameters along with very low elastic and electromechanical losses and dispersion over a wide frequency range and can be used in various high-power ultrasonic applications.展开更多
0.96(K_(0.5)Na_(0.5-z)Li_(z))(Nb_(0.92)Sb_(0.08))O_(3)-0.04(Ca_(0.5)Sr_(0.5))ZrO_(3)[(KN_(0.5-z)L_(z))NS-CSZ]piezoceramics(0≤z≤0.04)were aligned in the[001]orientation using 3%(in mole)NaNbO_(3)templates with a larg...0.96(K_(0.5)Na_(0.5-z)Li_(z))(Nb_(0.92)Sb_(0.08))O_(3)-0.04(Ca_(0.5)Sr_(0.5))ZrO_(3)[(KN_(0.5-z)L_(z))NS-CSZ]piezoceramics(0≤z≤0.04)were aligned in the[001]orientation using 3%(in mole)NaNbO_(3)templates with a large Lotgering factor(>97%).Their crystal structures transformed from the orthorhombic-pseudocubic(O-P)structure to the orthorhombic-tetragonal-pseudocubic(O-T-P)structure with an increasing z.The P structure was interpreted as a rhombohedral R3m structure.The piezoelectricity of the compositions increased after[001]-texturing,and the enhancement was proportional to the O phase quantity.The composition(z=0.03)exhibited the highest piezoelectric constant(d_(33);670 pC/N)and electromechanical coupling factor(k_(p);0.56).Piezoelectric energy harvesters were produced using the untextured and textured samples(z=0.03).The textured harvester delivered a large power density of 26.6 mW/mm^(3),which was larger than that of the untextured harvester owing to the enhanced kp and d_(33)×g_(33) of the textured piezoceramic.A multilayer actuator was produced using the textured sample(z=0.03),and it exhibited a large acceleration(44.2 G)and displacement(±3,730 mm)at±25 V.Therefore,the[001]-textured(KN_(0.47)L_(0.03))NS-CSZ piezoceramic is suitable for piezoelectric energy harvesters and actuators.展开更多
The recent review for the Restriction of Hazardous Substances Directive(RoHS)by the expert committee,appointed by the European Union,stated that the replacement of PZT“…may be scientifically and technologically prac...The recent review for the Restriction of Hazardous Substances Directive(RoHS)by the expert committee,appointed by the European Union,stated that the replacement of PZT“…may be scientifically and technologically practical to a certain degree…”,although replacement“…is scientifically and technically still impractical in the majority of applications.”Thus,two decades of sustained research and development may be approaching fruition,at first limited to a minority of applications.Therefore,it is of paramount importance to assess the viability of lead-free piezoceramics over a broad range of application-relevant properties.These are identified and discussed in turn:1.Cost,2.Reproducibility,3.Mechanical and Thermal Properties,4.Electrical Conductivity,and 5.Lifetime.It is suggested that the worldwide efforts into the development of lead-free piezoceramics now require a broader perspective to bring the work to the next stage of development by supporting implementation into real devices.Guidelines about pertinent research requirements into a wide range of secondary properties,measurement techniques,and salient literature are provided.展开更多
In this review,the evolution of high strain Na_(0.5)Bi_(0.5)TiO_(3)-based lead-free piezoceramics and their multilayer actuators has been explored.First,in terms of Na_(0.5)Bi_(0.5)TiO_(3)-based ceramic materials,the ...In this review,the evolution of high strain Na_(0.5)Bi_(0.5)TiO_(3)-based lead-free piezoceramics and their multilayer actuators has been explored.First,in terms of Na_(0.5)Bi_(0.5)TiO_(3)-based ceramic materials,the origin of high strain,the typical chemical modification methods of obtaining large strain and extrinsic factors affecting the large strain are discussed.Then it briefly summarizes the problems existing in Na_(0.5)Bi_(0.5)TiO_(3)-based ceramics for multilayer actuator applications.Strategies to optimize strain performance by means of microstructure control and phase structure design are also discussed.Thereafter,in terms of multilayer actuator,we describe its characteristics,applications and preparation process systematically,as well as the recent development of Na_(0.5)Bi_(0.5)TiO_(3)-based multilayer actuator.At last,perspectives on directions of following work and promising fields for the applications of the materials and their devices are presented.展开更多
Low-temperature sintered(Na_(1/2)Bi_(1/2))_(0.935)Ba_(0.065)Ti_(0.975)(Fe_(1/2)Nb_(1/2))_(0.025)O_(3)(NBT-BT-0.025FN)lead-free incipient piezoceramics were investigated using high-purity Li_(2)CO_(3) as sintering aids...Low-temperature sintered(Na_(1/2)Bi_(1/2))_(0.935)Ba_(0.065)Ti_(0.975)(Fe_(1/2)Nb_(1/2))_(0.025)O_(3)(NBT-BT-0.025FN)lead-free incipient piezoceramics were investigated using high-purity Li_(2)CO_(3) as sintering aids.With the ≤0.5 wt%Li_(2)CO_(3) addition,the introduced Li^(+) cations precede to enter the A-sites of the perovskite lattice to compensate for the A-site deficiencies.Once the addition exceeds 0.5 wt%,the excess Lit cations will occupy B-sites and give rise to the generation of oxygen vacancies,which accelerate the mass transport and thus lower the sintering temperature effectively from 1100℃ down to 925℃.It was also found that a small amount of Lit addition has little effect on the phase structure and electromechanical properties of the system,but overweight seriously disturbs these characteristics because of the large lattice distortion.The sintered NBT-BT-0.025FN incipient piezoceramics with 1.25 wt%Li_(2)CO_(3) addition at 925℃ provides a large strain of 0.33% and a corresponding large signal piezoelectric coefficient d_(33)^(*) of 550 pm/V at 60 kV/cm,indicating this system is a very promising candidate for lead-free co-fired multilayer actuator application.展开更多
Ga2O3 was doped into 0.95（K0.48Na0.52）NbO3-0.05LiTaO3 （KNN-LT） cera- mics and its influences on the sintering behavior, phase structure and electrical properties of ceramics were studied. Firstly, SEM observation ...Ga2O3 was doped into 0.95（K0.48Na0.52）NbO3-0.05LiTaO3 （KNN-LT） cera- mics and its influences on the sintering behavior, phase structure and electrical properties of ceramics were studied. Firstly, SEM observation exhibits that more and more glass phase appears in ceramics with the gradual addition of Ga2O3, which determines the continuous decrease in sintering temperatures. And the addition of Ga2O3 is also found to increase the orthorhombic-tetragonal transition temperature （To-T） of system to a higher level. Secondly, both the density and the coercive field （Ec） of ceramics increase firstly and then decrease with increasing the Ga2O3 content, and the KNN-LT-xGa sample at x = 0.004 shows a pinched P-E hysteresis loop. Finally, the impedance characteristics of KNN-LT-xGa ceramics were investigated at different temperatures, revealing a typical vacancy related conduction mechanism. This work demonstrates that Ga2O3 is a good sintering aid for KNN-based ceramics, and the vacancy plays an important role in the sintering and electrical behaviors of ceramics.展开更多
In this paper,the results of experimental study of dispersion characteristics of complex electromechanical parameters of ferroelectrically“hard”porous piezoceramics based on PZT composition were presented.Experiment...In this paper,the results of experimental study of dispersion characteristics of complex electromechanical parameters of ferroelectrically“hard”porous piezoceramics based on PZT composition were presented.Experimental samples of porous piezoceramics were fabricated using a modified method of burning-out a pore former.The complex constants of porous piezoceramics with relative porosity 16%and their frequency dependences were measured using the piezoelectric resonance analysis method.As a result of experimental studies,regions of elastic,piezoelectric and electromechanical dispersion,characterized by anomalies in the frequency dependences of the imaginary and real parts of the complex constants of porous piezoelectric ceramics were found.It was revealed also that the microstructural features of porous piezoceramics determine the character of frequency dependences of complex electromechanical parameters of porous piezoelectric ceramics.In conclu-sion,the microstructural and physical mechanisms of electromechanical losses and dispersion in porous piezoceramics were discussed.展开更多
In this paper,a comprehensive study of microstructure/properties interrelations for porous piezoceramics based on PZT composition was performed.Experimental samples of porous piezoceramics were fabricated using a modi...In this paper,a comprehensive study of microstructure/properties interrelations for porous piezoceramics based on PZT composition was performed.Experimental samples of porous piezoceramics were fabricated using a modified method of burningout a pore former.Porosity dependencies of elastic,dielectric,piezoelectric and electromechanical coefficients of the porous ceramics in the relative porosity range 0-50%were obtained and analyzed.As a result of microstructure analysis,it was found that at any connectivity type(3-0,3-3)and porosity up to 50%the real structures of porous piezoceramics were close to the matrix medium structure with continuous piezoceramic skeleton.It was also revealed that the microstructural features of porous piezoceramics define the character of the dependences of the dielectric,piezoelectric and electromechanical properties of porous piezoelectric ceramics on porosity.In conclusion,microstructure/properties interrelations,as well as new applications of porous piezoceramics were discussed.展开更多
The effect of a constant electric field(E)on the absorption of microwave electromagnetic energy(L)by BaTiO_(3) crystals and the highly sensitive PCR-1 piezoceramic was studied.The field dependence of the absorption va...The effect of a constant electric field(E)on the absorption of microwave electromagnetic energy(L)by BaTiO_(3) crystals and the highly sensitive PCR-1 piezoceramic was studied.The field dependence of the absorption value LeET at the maximum of the spectrum Lef T has the form of a“butterfly”,and the dependence of the frequency shift of the maximum on the field strength f eET has a hysteretic character.The PCR-1 Lef T absorption spectrum at high E is modulated by pulses in a wide frequency range.It is assumed that the cause of the amplitude-frequency modulation of the spectrum may be the electromagnetic radiation of incomplete local discharges at the surface of piezoceramics.The change in the magnitude and position of the resonance maximum in the absorption spectra and the appearance of amplitude-frequency modulation Lef T when exposed to a constant field is interpreted from the point of view of changes in the parameters and concentration of the domains walls,as well as the a-and c-domain wedges of mechanical twins resonating in the electromagnetic field.展开更多
The study of BiFeO_(3)-0.3BaTiO_(3) ceramics has gained significant attention due to their high Curie temperature(TC≥450℃)and excellent piezoelectric properties(d33≥200 pC·N^(−1)).These are particularly pronou...The study of BiFeO_(3)-0.3BaTiO_(3) ceramics has gained significant attention due to their high Curie temperature(TC≥450℃)and excellent piezoelectric properties(d33≥200 pC·N^(−1)).These are particularly pronounced near the morphotropic phase boundary(MPB)region where coexisting rhombohedral and pseudocubic(R-PC)phases are observed.In addition,as the BaTiO_(3) content increases,BiFeO_(3)-BaTiO_(3) ceramics gradually become dominated by a single pseudocubic(PC-)phase.This shift results in a decrease in piezoelectric properties but an enhancement in strain performance.However,the underlying mechanism remains unclear.The high strain properties observed in non-MPB compositions provide a motivation for further investigation into these mechanisms.This paper presents a detailed analysis of the electric-field and temperature-induced domain structure evolution in BiFeO_(3)-0.4BaTiO_(3),which is predominately characterized by the PC phase.Piezoresponse force microscope(PFM)observations reveal the presence of nanodomains and stripy domains associated with polar nanoregions(PNRs),as well as relaxor ferroelectrics(RFEs)and/or ferroelectrics(FEs).The RFEs exhibit a significantly better strain response than the FEs,providing direct evidence for the enhanced strain properties of RFEs.Elevated-temperature Raman spectroscopy confirms a decrease in B-O bonding and BO6 deformation,along with an increase in structural symmetry,indicating the formation of RFEs and/or PNRs.The phase diagram shows the Burns temperature(TB),dielectric maxima temperature(Tm)and freezing temperature(Tf)evaluated from the dielectric spectra;the temperature-induced evolution of domain structures;and the sequential quasi-dielectric states:PNRs,RFEs and FEs.The evolution of the domain structure,including the morphology and ratio of FEs,RFEs and PNRs,induced by either electric-fields or temperature strongly affects the strain properties of RFEs.A superior piezoelectric coefficient of d33*=533 pm·V^(−1) at 40 kV·cm^(−1) and a large electric strain of Suni=0.285%are obtained.These results further validate that domain modulation can effectively enhance the strain properties of BiFeO_(3)-BaTiO_(3) ceramics,which makes them promising candidates for actuator applications.展开更多
Porous piezoceramics are of interest for applications such as low frequency hydrophones. Porous(K,Na,Li)NbO_3-BaZrO_3-(Bi,Na)TiO_3 lead-free piezoceramics having vertical morphotropic phase boundary composition were f...Porous piezoceramics are of interest for applications such as low frequency hydrophones. Porous(K,Na,Li)NbO_3-BaZrO_3-(Bi,Na)TiO_3 lead-free piezoceramics having vertical morphotropic phase boundary composition were fabricated by adding 30 μm-diameter acrylic resins. The ceramic powders were synthesized by a conventional solid-state reaction method and then mixed with the resins. Volume ratios of ceramics to resin were 90:10, 80:20, 70:30, and 60:40. After burning out the resins and binder, the specimens were sintered at 1170–1190 ℃ for 5 h. The porous specimen with 30 vol% acrylic resin had longitudinal acoustic velocity of 4518 m/s, acoustic impedance of 16.44 Mkg/(m^2·s), and hydrostatic figure of merit of 405×10^(-15)m^2/N. The hydrostatic figure of merit was about 4 times of that of monolithic ceramics. Compared with monolithic ceramics, the porous specimen had a better transducer sensitivity for underwater applications.展开更多
Lead-free piezoceramics based on the(Ba,Ca)(Zr,Ti)O3(BCZT) system exhibit excellent electromechanical properties for low-temperature actuation applications, but suffer from relatively high processing temperatures. Her...Lead-free piezoceramics based on the(Ba,Ca)(Zr,Ti)O3(BCZT) system exhibit excellent electromechanical properties for low-temperature actuation applications, but suffer from relatively high processing temperatures. Here we demonstrate an approach for the reduction of the sintering temperature and simultaneous increase of the electromechanical strain response of(Ba,Ca)(Zr,Ti)O3 piezoceramics by aliovalent doping with Ce. The samples were prepared by solid state synthesis and their crystallographic structure, dielectric, ferroelectric, and electromechanical properties were investigated. The highest d33* value of 1189 pm/V was obtained for the sample with 0.05 mol% Ce, substituted on the A-site of the perovskite lattice. The results indicate a large potential of these materials for off-resonance piezoelectric actuators.展开更多
Smart material and structure (SMS) is a challenging novel technique for the 21 century especially in fields of aviation and aerospace. Vibration and noise suppression smart structure is an important branch of SMS. T...Smart material and structure (SMS) is a challenging novel technique for the 21 century especially in fields of aviation and aerospace. Vibration and noise suppression smart structure is an important branch of SMS. There are several typical structures such as the cabin of an airplane, space station, the solar board of satellite and the rotor blade of a helicopter, of which the vibrations and radiation noises have bad influences on precise equipments and aiming systems. In order to suppress vibrations and noises of these structures, several algorithms are applied to the models which simulate the structures. Experiments are performed to suppress vibrations and noises by bonding sensors and actuators to the structures at the optimized locations and using computer based measurement and control systems. For the blade vibration control of a helicopter, a non contact method of signal transmission by magneto electric coupling is discussed. The experimental results demonstrate that the methods used for active control are effective.展开更多
High-piezoelectric properties in lead-free materials have been the pursuit for both industry and scientific research.In this work,the synergistic approaches of phase/domain engineering and novel poling method are adop...High-piezoelectric properties in lead-free materials have been the pursuit for both industry and scientific research.In this work,the synergistic approaches of phase/domain engineering and novel poling method are adopted for the improvement of piezoelectric performance.The strategically designed lead-free donor-doped BiFeO_(3)-x BaTiO_(3) ceramics at the crystal structure morphotropic phase boundary(MPB)between the rhombohedral and tetragonal phases exhibited a high Curie temperature(T C≥450°C).Furthermore,si-multaneously enhanced static piezoelectric constant(d_(33))of 436±5 pC/N and thermally stable dynamic piezoelectric constant(d_(33)^(∗))of 550±10 pm/V were achieved.The high piezoelectric performance is col-lectively attributed to the crystal structure MPB,thermal quenching effect,local structure heterogeneity induced by donor doping,mesoscale nanodomains,and novel poling method inside a magnetic field.The temperature-insensitive and high piezoelectric performance of the current work is superior to the other lead-free piezoceramics.The synergistic approach for the improvement of piezoelectricity provides a path for the development of lead-free ceramics for high-temperature commercial applications.展开更多
In order to monitor the basic mechanical properties and interior damage of concrete structures,the piezoelectric actuator/sensor based wave propagation method was investigated experimentally in the laboratory using a ...In order to monitor the basic mechanical properties and interior damage of concrete structures,the piezoelectric actuator/sensor based wave propagation method was investigated experimentally in the laboratory using a specifically designed test setup.The energy attenuation of stress waves was measured by the relative index between the output voltage of sensors and the excitation voltage at the actuator.Based on the experimental results of concrete cube and cylinder specimens,the effect of excitation frequencies,excitation amplitude,wave propagation paths and the curing age on the output signals of sensors are evaluated.The results show that the relative voltage attenuation coefficient RVAC is an effective indicator for measuring the attenuation of stress waves through the interior of concrete.展开更多
This paper concerns the optimization problem for multilayered ultrasonic transducer with active porous piezoelectric layer. The dependences of the effective moduli for porous piezoelectric material on porosity have be...This paper concerns the optimization problem for multilayered ultrasonic transducer with active porous piezoelectric layer. The dependences of the effective moduli for porous piezoelectric material on porosity have been previously obtained and allowed to decrease the number of design variables. The multiobjective optimization problem based on the Pareto-frontier calculation has been solved using the live-link of finite-element (FE) package Comsol Multiphysics with MATLAB.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52272103 and 52072010)Beijing Natural Science Foundation(Grant Nos.2242029 and JL23004).
文摘High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments.
文摘Pb(Mn_(1/3)Sb_(2/3))x(Zn_(1/3)Nb_(2/3))y(Zr_(0.535)Ti_(0.465)),_(1-x-y)O_(3)(PMZN)piezoelectric ceramics were fabricated,The effects of sintering temperature and heat-treatment time on properties wen discussed,the optimum preparation technology parameters were obtained.In this case,the ceramics have the highest electromechanical coupling coefficients and mechanical quality factor and the least dielectric loss.It is revealed that the PMZN piezo-ceramics material can be utilized for high-power ultrasound transducers.
基金financially supported by the Russian Science Foundation Grant No.24-22-00063,https:/rscf.ru/project/24-22-00063/at the Southern Federal University.
文摘This paper studies the relaxation processes and electromechanical hysteresis in relaxor piezoceramics based on the PzT system.Measurements and analysis of the electric displacement and mechanical strain hysteresis loops recorded in bipolar AC electric fields in the frequency range 0.001-5 Hz were performed by means of the electromechanical response characterization system(STEPHV)and program(STEP).It was found that the coercive field,remnant and saturation electric displacement,area of hysteresis loops and relative mechanical strain values are strongly dependent on frequency.As a result of this study,complete sets of parameters characterizing the switching and ferroelectric hysteresis processes in relaxor piezoceramics were obtained.
基金the support of the National Nature Science Foundation of China(No.52325204)We acknowledge DESY(Hamburg,Germany),a member of the HelmholtzGemeinschaft deutscher Forschungszentren(HGF)for the provision of experimental facilities.Parts of this research were carried out at PETRA III(Proposal No.I-20220242)we would like to thank Alexander Schökel for assistance in using the beamline P02.1.
文摘This study investigates the relationship between the electro-mechanical properties of Cu-doped potassium sodium niobate(KNN)piezoceramics driven at high vibration velocities and their structural origins.Intrinsic and extrinsic contributions to the dynamic strain were quantified at high-power resonance conditions by in-situ high-energy X-ray diffraction.These contributions were correlated to the observed sub-coercive dielectric and piezoelectric responses.Cu doping impairs extrinsic contributions of KNN due to the movement of none180°domains,akin to acceptor-doped hard PZT,reducing the fraction of transverse strain originating from none180°domain wall motion over the total strain of 5%at 0.8 m/s.Therefore,the performance of Cu-doped KNN and PZT were found to be comparable.Both systems exhibit a high mechanical quality factor at low vibration velocity,which decreases at high displacement rates.Additionally,the temperature dependence of electromechanical properties for different Cu doping amounts was investigated.In particular,the mechanical quality factor at the vibration velocity of 1 m/s in a temperature range of-40℃to 140℃was studied.According to thefindings,the composition doped with 0.5%Cu exhibited a stable vibration at 1 m/s,with only 10%variation in the mechanical quality factor between 20C and 140℃.
基金financially supported by the Russian Science Foundation Grant No.24-22-00063,https:/rscf.ru/project/24-22-00063/at the Southern Federal University.
文摘In this paper,we present the experimental results of the comprehensive study of the microstructural features and complex dielectric,elastic and electromechanical properties of the ferroelectrically“hard”piezoceramics based on the lead zirconate titanate(PZT)composition.For the measurements and analysis of the real and imaginary parts of the complex parameters of the studied piezoceramics as well as their frequency dependences,we used precision impedance analyzer Agilent 4294A and Piezoelectric Resonance Analysis Program(PRAP)software.We have found that the studied piezoceramics demonstrate a unique combination of dielectric,elastic and electromechanical parameters along with very low elastic and electromechanical losses and dispersion over a wide frequency range and can be used in various high-power ultrasonic applications.
基金supported by a National Research Foundation(NRF)of Korea grant funded by the Korean government(MSIT)(No.RS-2023-00254689).
文摘0.96(K_(0.5)Na_(0.5-z)Li_(z))(Nb_(0.92)Sb_(0.08))O_(3)-0.04(Ca_(0.5)Sr_(0.5))ZrO_(3)[(KN_(0.5-z)L_(z))NS-CSZ]piezoceramics(0≤z≤0.04)were aligned in the[001]orientation using 3%(in mole)NaNbO_(3)templates with a large Lotgering factor(>97%).Their crystal structures transformed from the orthorhombic-pseudocubic(O-P)structure to the orthorhombic-tetragonal-pseudocubic(O-T-P)structure with an increasing z.The P structure was interpreted as a rhombohedral R3m structure.The piezoelectricity of the compositions increased after[001]-texturing,and the enhancement was proportional to the O phase quantity.The composition(z=0.03)exhibited the highest piezoelectric constant(d_(33);670 pC/N)and electromechanical coupling factor(k_(p);0.56).Piezoelectric energy harvesters were produced using the untextured and textured samples(z=0.03).The textured harvester delivered a large power density of 26.6 mW/mm^(3),which was larger than that of the untextured harvester owing to the enhanced kp and d_(33)×g_(33) of the textured piezoceramic.A multilayer actuator was produced using the textured sample(z=0.03),and it exhibited a large acceleration(44.2 G)and displacement(±3,730 mm)at±25 V.Therefore,the[001]-textured(KN_(0.47)L_(0.03))NS-CSZ piezoceramic is suitable for piezoelectric energy harvesters and actuators.
文摘The recent review for the Restriction of Hazardous Substances Directive(RoHS)by the expert committee,appointed by the European Union,stated that the replacement of PZT“…may be scientifically and technologically practical to a certain degree…”,although replacement“…is scientifically and technically still impractical in the majority of applications.”Thus,two decades of sustained research and development may be approaching fruition,at first limited to a minority of applications.Therefore,it is of paramount importance to assess the viability of lead-free piezoceramics over a broad range of application-relevant properties.These are identified and discussed in turn:1.Cost,2.Reproducibility,3.Mechanical and Thermal Properties,4.Electrical Conductivity,and 5.Lifetime.It is suggested that the worldwide efforts into the development of lead-free piezoceramics now require a broader perspective to bring the work to the next stage of development by supporting implementation into real devices.Guidelines about pertinent research requirements into a wide range of secondary properties,measurement techniques,and salient literature are provided.
基金the support by the National Natural Science Foundation of China(No.U1732117,51902111 and 51672092)the China Postdoctoral Science Foundation(No.2019M662602)+1 种基金the Open Fund of Guangxi Key Laboratory of Information Materials(No.191015-K)the Donguan Innovative Research Team Program.
文摘In this review,the evolution of high strain Na_(0.5)Bi_(0.5)TiO_(3)-based lead-free piezoceramics and their multilayer actuators has been explored.First,in terms of Na_(0.5)Bi_(0.5)TiO_(3)-based ceramic materials,the origin of high strain,the typical chemical modification methods of obtaining large strain and extrinsic factors affecting the large strain are discussed.Then it briefly summarizes the problems existing in Na_(0.5)Bi_(0.5)TiO_(3)-based ceramics for multilayer actuator applications.Strategies to optimize strain performance by means of microstructure control and phase structure design are also discussed.Thereafter,in terms of multilayer actuator,we describe its characteristics,applications and preparation process systematically,as well as the recent development of Na_(0.5)Bi_(0.5)TiO_(3)-based multilayer actuator.At last,perspectives on directions of following work and promising fields for the applications of the materials and their devices are presented.
基金the generous support by the National Natural Science Foundation of China under grant no.51672092 and U1732117by the Project of Henan Province Science and Technology(Grant No.172102210380)+1 种基金China Postdoctoral Science Foundation funded project no.2018M632847the generous support by Wuhan Morning Light Plan of Youth Science and Technology(No.2017050304010299).
文摘Low-temperature sintered(Na_(1/2)Bi_(1/2))_(0.935)Ba_(0.065)Ti_(0.975)(Fe_(1/2)Nb_(1/2))_(0.025)O_(3)(NBT-BT-0.025FN)lead-free incipient piezoceramics were investigated using high-purity Li_(2)CO_(3) as sintering aids.With the ≤0.5 wt%Li_(2)CO_(3) addition,the introduced Li^(+) cations precede to enter the A-sites of the perovskite lattice to compensate for the A-site deficiencies.Once the addition exceeds 0.5 wt%,the excess Lit cations will occupy B-sites and give rise to the generation of oxygen vacancies,which accelerate the mass transport and thus lower the sintering temperature effectively from 1100℃ down to 925℃.It was also found that a small amount of Lit addition has little effect on the phase structure and electromechanical properties of the system,but overweight seriously disturbs these characteristics because of the large lattice distortion.The sintered NBT-BT-0.025FN incipient piezoceramics with 1.25 wt%Li_(2)CO_(3) addition at 925℃ provides a large strain of 0.33% and a corresponding large signal piezoelectric coefficient d_(33)^(*) of 550 pm/V at 60 kV/cm,indicating this system is a very promising candidate for lead-free co-fired multilayer actuator application.
基金This work was supported by the National Natural Science Foundation of China （Grant No. 51332003）.
文摘Ga2O3 was doped into 0.95（K0.48Na0.52）NbO3-0.05LiTaO3 （KNN-LT） cera- mics and its influences on the sintering behavior, phase structure and electrical properties of ceramics were studied. Firstly, SEM observation exhibits that more and more glass phase appears in ceramics with the gradual addition of Ga2O3, which determines the continuous decrease in sintering temperatures. And the addition of Ga2O3 is also found to increase the orthorhombic-tetragonal transition temperature （To-T） of system to a higher level. Secondly, both the density and the coercive field （Ec） of ceramics increase firstly and then decrease with increasing the Ga2O3 content, and the KNN-LT-xGa sample at x = 0.004 shows a pinched P-E hysteresis loop. Finally, the impedance characteristics of KNN-LT-xGa ceramics were investigated at different temperatures, revealing a typical vacancy related conduction mechanism. This work demonstrates that Ga2O3 is a good sintering aid for KNN-based ceramics, and the vacancy plays an important role in the sintering and electrical behaviors of ceramics.
基金The study was financially supported by the Ministry of Science and Higher Education of the Russian Federation[State task in the field of scientific activity,Scientific Project No.0852-2020-0032(BAS0110/20-3-08IF)].
文摘In this paper,the results of experimental study of dispersion characteristics of complex electromechanical parameters of ferroelectrically“hard”porous piezoceramics based on PZT composition were presented.Experimental samples of porous piezoceramics were fabricated using a modified method of burning-out a pore former.The complex constants of porous piezoceramics with relative porosity 16%and their frequency dependences were measured using the piezoelectric resonance analysis method.As a result of experimental studies,regions of elastic,piezoelectric and electromechanical dispersion,characterized by anomalies in the frequency dependences of the imaginary and real parts of the complex constants of porous piezoelectric ceramics were found.It was revealed also that the microstructural features of porous piezoceramics determine the character of frequency dependences of complex electromechanical parameters of porous piezoelectric ceramics.In conclu-sion,the microstructural and physical mechanisms of electromechanical losses and dispersion in porous piezoceramics were discussed.
基金The study was financially supported by the Ministry of Science and Higher Education of the Russian Federation[State task in the field of scientific activity,Scientific Project No.0852-2020-0032(BAS0110/20-3-08IF)].
文摘In this paper,a comprehensive study of microstructure/properties interrelations for porous piezoceramics based on PZT composition was performed.Experimental samples of porous piezoceramics were fabricated using a modified method of burningout a pore former.Porosity dependencies of elastic,dielectric,piezoelectric and electromechanical coefficients of the porous ceramics in the relative porosity range 0-50%were obtained and analyzed.As a result of microstructure analysis,it was found that at any connectivity type(3-0,3-3)and porosity up to 50%the real structures of porous piezoceramics were close to the matrix medium structure with continuous piezoceramic skeleton.It was also revealed that the microstructural features of porous piezoceramics define the character of the dependences of the dielectric,piezoelectric and electromechanical properties of porous piezoelectric ceramics on porosity.In conclusion,microstructure/properties interrelations,as well as new applications of porous piezoceramics were discussed.
基金The authors are grateful to the chief researcher of the Research Institute of Physics of the Southern Federal University,Rybyanets A.N.for the samples of piezoceramics provided for research.
文摘The effect of a constant electric field(E)on the absorption of microwave electromagnetic energy(L)by BaTiO_(3) crystals and the highly sensitive PCR-1 piezoceramic was studied.The field dependence of the absorption value LeET at the maximum of the spectrum Lef T has the form of a“butterfly”,and the dependence of the frequency shift of the maximum on the field strength f eET has a hysteretic character.The PCR-1 Lef T absorption spectrum at high E is modulated by pulses in a wide frequency range.It is assumed that the cause of the amplitude-frequency modulation of the spectrum may be the electromagnetic radiation of incomplete local discharges at the surface of piezoceramics.The change in the magnitude and position of the resonance maximum in the absorption spectra and the appearance of amplitude-frequency modulation Lef T when exposed to a constant field is interpreted from the point of view of changes in the parameters and concentration of the domains walls,as well as the a-and c-domain wedges of mechanical twins resonating in the electromagnetic field.
基金supported by the National Key Research and Development Program(No.2022YFB3807400)the National Natural Science Foundation of China(Nos.52072028 and 52032007).
文摘The study of BiFeO_(3)-0.3BaTiO_(3) ceramics has gained significant attention due to their high Curie temperature(TC≥450℃)and excellent piezoelectric properties(d33≥200 pC·N^(−1)).These are particularly pronounced near the morphotropic phase boundary(MPB)region where coexisting rhombohedral and pseudocubic(R-PC)phases are observed.In addition,as the BaTiO_(3) content increases,BiFeO_(3)-BaTiO_(3) ceramics gradually become dominated by a single pseudocubic(PC-)phase.This shift results in a decrease in piezoelectric properties but an enhancement in strain performance.However,the underlying mechanism remains unclear.The high strain properties observed in non-MPB compositions provide a motivation for further investigation into these mechanisms.This paper presents a detailed analysis of the electric-field and temperature-induced domain structure evolution in BiFeO_(3)-0.4BaTiO_(3),which is predominately characterized by the PC phase.Piezoresponse force microscope(PFM)observations reveal the presence of nanodomains and stripy domains associated with polar nanoregions(PNRs),as well as relaxor ferroelectrics(RFEs)and/or ferroelectrics(FEs).The RFEs exhibit a significantly better strain response than the FEs,providing direct evidence for the enhanced strain properties of RFEs.Elevated-temperature Raman spectroscopy confirms a decrease in B-O bonding and BO6 deformation,along with an increase in structural symmetry,indicating the formation of RFEs and/or PNRs.The phase diagram shows the Burns temperature(TB),dielectric maxima temperature(Tm)and freezing temperature(Tf)evaluated from the dielectric spectra;the temperature-induced evolution of domain structures;and the sequential quasi-dielectric states:PNRs,RFEs and FEs.The evolution of the domain structure,including the morphology and ratio of FEs,RFEs and PNRs,induced by either electric-fields or temperature strongly affects the strain properties of RFEs.A superior piezoelectric coefficient of d33*=533 pm·V^(−1) at 40 kV·cm^(−1) and a large electric strain of Suni=0.285%are obtained.These results further validate that domain modulation can effectively enhance the strain properties of BiFeO_(3)-BaTiO_(3) ceramics,which makes them promising candidates for actuator applications.
基金partly supported by the CAS/SAFEA International Partnership Program for Creative Research Teams
文摘Porous piezoceramics are of interest for applications such as low frequency hydrophones. Porous(K,Na,Li)NbO_3-BaZrO_3-(Bi,Na)TiO_3 lead-free piezoceramics having vertical morphotropic phase boundary composition were fabricated by adding 30 μm-diameter acrylic resins. The ceramic powders were synthesized by a conventional solid-state reaction method and then mixed with the resins. Volume ratios of ceramics to resin were 90:10, 80:20, 70:30, and 60:40. After burning out the resins and binder, the specimens were sintered at 1170–1190 ℃ for 5 h. The porous specimen with 30 vol% acrylic resin had longitudinal acoustic velocity of 4518 m/s, acoustic impedance of 16.44 Mkg/(m^2·s), and hydrostatic figure of merit of 405×10^(-15)m^2/N. The hydrostatic figure of merit was about 4 times of that of monolithic ceramics. Compared with monolithic ceramics, the porous specimen had a better transducer sensitivity for underwater applications.
基金funded by Ministry of Science,Research and Technology of Iran as a Ph.D.project,with Grant No.481392053,at Materials&Energy Research Center(MERC)supported by Deutsche Forschungsgemeinschaft under the Sonderforschungsbereich 595(SFB 595)fellowship
文摘Lead-free piezoceramics based on the(Ba,Ca)(Zr,Ti)O3(BCZT) system exhibit excellent electromechanical properties for low-temperature actuation applications, but suffer from relatively high processing temperatures. Here we demonstrate an approach for the reduction of the sintering temperature and simultaneous increase of the electromechanical strain response of(Ba,Ca)(Zr,Ti)O3 piezoceramics by aliovalent doping with Ce. The samples were prepared by solid state synthesis and their crystallographic structure, dielectric, ferroelectric, and electromechanical properties were investigated. The highest d33* value of 1189 pm/V was obtained for the sample with 0.05 mol% Ce, substituted on the A-site of the perovskite lattice. The results indicate a large potential of these materials for off-resonance piezoelectric actuators.
文摘Smart material and structure (SMS) is a challenging novel technique for the 21 century especially in fields of aviation and aerospace. Vibration and noise suppression smart structure is an important branch of SMS. There are several typical structures such as the cabin of an airplane, space station, the solar board of satellite and the rotor blade of a helicopter, of which the vibrations and radiation noises have bad influences on precise equipments and aiming systems. In order to suppress vibrations and noises of these structures, several algorithms are applied to the models which simulate the structures. Experiments are performed to suppress vibrations and noises by bonding sensors and actuators to the structures at the optimized locations and using computer based measurement and control systems. For the blade vibration control of a helicopter, a non contact method of signal transmission by magneto electric coupling is discussed. The experimental results demonstrate that the methods used for active control are effective.
基金the National Key Research and Development Program of China(Grant No.2022YFB3807404)the Special Funding Support for the Construction of Innovative Provinces in Hunan Province of China(Grant No.2020GK2062)Xuefan Zhou(Postdoc)is particularly grateful for the support from the China National Postdoctoral Program for Innovative Talents (Grant No. BX2021377 ).
文摘High-piezoelectric properties in lead-free materials have been the pursuit for both industry and scientific research.In this work,the synergistic approaches of phase/domain engineering and novel poling method are adopted for the improvement of piezoelectric performance.The strategically designed lead-free donor-doped BiFeO_(3)-x BaTiO_(3) ceramics at the crystal structure morphotropic phase boundary(MPB)between the rhombohedral and tetragonal phases exhibited a high Curie temperature(T C≥450°C).Furthermore,si-multaneously enhanced static piezoelectric constant(d_(33))of 436±5 pC/N and thermally stable dynamic piezoelectric constant(d_(33)^(∗))of 550±10 pm/V were achieved.The high piezoelectric performance is col-lectively attributed to the crystal structure MPB,thermal quenching effect,local structure heterogeneity induced by donor doping,mesoscale nanodomains,and novel poling method inside a magnetic field.The temperature-insensitive and high piezoelectric performance of the current work is superior to the other lead-free piezoceramics.The synergistic approach for the improvement of piezoelectricity provides a path for the development of lead-free ceramics for high-temperature commercial applications.
基金Funded by the National Natural Science Foundation of China (No.50708065)the National High-tech R&D Program(863 Program )(No.2007-AA-11-Z-113)the Key Projects in the Science and Technology Pillar Program of Tianjin(No.11ZCKFSF00300)
文摘In order to monitor the basic mechanical properties and interior damage of concrete structures,the piezoelectric actuator/sensor based wave propagation method was investigated experimentally in the laboratory using a specifically designed test setup.The energy attenuation of stress waves was measured by the relative index between the output voltage of sensors and the excitation voltage at the actuator.Based on the experimental results of concrete cube and cylinder specimens,the effect of excitation frequencies,excitation amplitude,wave propagation paths and the curing age on the output signals of sensors are evaluated.The results show that the relative voltage attenuation coefficient RVAC is an effective indicator for measuring the attenuation of stress waves through the interior of concrete.
文摘This paper concerns the optimization problem for multilayered ultrasonic transducer with active porous piezoelectric layer. The dependences of the effective moduli for porous piezoelectric material on porosity have been previously obtained and allowed to decrease the number of design variables. The multiobjective optimization problem based on the Pareto-frontier calculation has been solved using the live-link of finite-element (FE) package Comsol Multiphysics with MATLAB.
