Journal articles: 'Lead based Piezoelectrics'

1

Handoko, Albertus D., and Gregory K. L. Goh. "Hydrothermal epitaxy of lead free (Na,K)NbO3-based piezoelectric films." MRS Proceedings 1547 (2013): 45–52. http://dx.doi.org/10.1557/opl.2013.634.

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ABSTRACTLead free niobate solid solutions can exhibit piezoelectric properties comparable to that of lead zirconate titanate piezoelectrics in the vicinity of its morphotropic phase boundary (MPB). Here we describe how (Na,K)NbO3 and (Na,K)NbO3-LiTaO3 solid solution thin films can be grown epitaxially by the hydrothermal method at temperatures of 200 °C or below in water and be made ferro- and piezoelectrically active by a simple 2 step post growth treatment.

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KOSEC, MARIJA, BARBARA MALIČ, ANDREJA BENČAN, TADEJ ROJAC, and JENNY TELLIER. "ALKALINE NIOBATE-BASED PIEZOCERAMICS: CRYSTAL STRUCTURE, SYNTHESIS, SINTERING AND MICROSTRUCTURE." Functional Materials Letters 03, no. 01 (March 2010): 15–18. http://dx.doi.org/10.1142/s1793604710000865.

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In this review, the crystal structure and the synthesis of the sodium potassium niobate ( K 0.5 Na 0.5 NbO 3) as a promising candidate for lead-free piezoelectrics are addressed. The sintering and the microstructure as prerequisites for obtaining ceramics with reliable and sufficiently high piezoelectric properties for selected applications are discussed.

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Shi, Hongwei, Kai Li, Feng Li, Jianxing Ma, Yubing Tu, Mingsheng Long, Yilin Lu, Weiping Gong, Chunchang Wang, and Lei Shan. "Enhanced Piezoelectricity and Thermal Stability of Electrostrain Performance in BiFeO3-Based Lead-Free Ceramics." Nanomaterials 13, no. 5 (March 5, 2023): 942. http://dx.doi.org/10.3390/nano13050942.

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BiFeO3–based ceramics possess an advantage over large spontaneous polarization and high Curie temperature, and are thus widely explored in the field of high–temperature lead–free piezoelectrics and actuators. However, poor piezoelectricity/resistivity and thermal stability of electrostrain make them less competitive. To address this problem, (1 − x) (0.65BiFeO3–0.35BaTiO3)–xLa0.5Na0.5TiO3 (BF–BT–xLNT) systems are designed in this work. It is found that piezoelectricity is significantly improved with LNT addition, which is contributed by the phase boundary effect of rhombohedral and pseudocubic phase coexistence. The small–signal and large–signal piezoelectric coefficient (d33 and d33*) peaks at x = 0.02 with 97 pC/N and 303 pm/V, respectively. The relaxor property and resistivity are enhanced as well. This is verified by Rietveld refinement, dielectric/impedance spectroscopy and piezoelectric force microscopy (PFM) technique. Interestingly, a good thermal stability of electrostrain is obtained at x = 0.04 composition with fluctuation η = 31% (Smax'−SRTSRT×100%), in a wide temperature range of 25–180 °C, which is considered as a compromise of negative temperature dependent electrostrain for relaxors and the positive one for ferroelectric matrix. This work provides an implication for designing high–temperature piezoelectrics and stable electrostrain materials.

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Kim, Sangwook, Hyunwook Nam, and Ilkan Calisir. "Lead-Free BiFeO3-Based Piezoelectrics: A Review of Controversial Issues and Current Research State." Materials 15, no. 13 (June 21, 2022): 4388. http://dx.doi.org/10.3390/ma15134388.

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Lead-free electroceramics represent an emerging area of research that has the potential to enable new green advances in electronics. Research has mainly focused on the development of new piezoelectric materials for replacing lead containing oxides exhibiting superior electromechanical behavior. Lead-free BiFeO3-based materials are not only the promising candidates to replace lead-based materials but also show intriguing properties which may inspire innovative material design for the next generation of lead-free piezoceramics. This review aims to highlight the current state of research and overlooked aspects in lead-free BiFeO3-based ceramics, which could be insightful in elucidating certain controversial issues. Current strategies to reduce high conductivity, influence of chemical heterogeneity on both functional properties and crystal structure, effective heat treatment procedures, and the role of pseudo-cubic structures on the enhancement of piezoelectric properties are subjects of highlighted within this review as they have a significant impact on the quality of BiFeO3-based lead-free piezoelectrics (but are often disregarded).

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Haugen, Astri Bjørnetun. "Hybrid Atmosphere Processing of Lead-Free Piezoelectric Sodium Potassium Niobate-Based Ceramics." Ceramics 2, no. 3 (July 17, 2019): 460–71. http://dx.doi.org/10.3390/ceramics2030035.

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K0.5Na0.5NbO3-based ceramics, a promising group of lead-free piezoelectrics, are challenging to sinter dense while avoiding alkali evaporation. This work explores hybrid atmosphere processing, a new approach where reducing atmospheres is used during heating to avoid coarsening from alkali carbonates and hydroxides, and oxidizing atmospheres is used during sintering to avoid alkali evaporation. Discs of Li0.06(K0.52Na0.48)0.94Nb0.71Ta0.29O3 with 0.25 mol% Mn (KNNLTM) were sintered in air, N2, 9% H2 in N2, or 9% H2 in N2 during heating and air during sintering (hybrid atmosphere processing). The highest density was obtained by sintering in 9% H2 in N2, but resulted in high alkali loss and decomposition of the surface, followed by low piezoelectric response. However, with the hybrid H2/air processing it was possible to both avoid surface decomposition and leakage currently associated with alkali evaporation during sintering in H2, and to obtain a denser, more phase-pure and small-grained KNNLTM ceramic with a higher piezoelectric response than obtained by sintering in air or N2.

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Huangfu, Geng, Kun Zeng, Binquan Wang, Jie Wang, Zhengqian Fu, Fangfang Xu, Shujun Zhang, Haosu Luo, Dwight Viehland, and Yiping Guo. "Giant electric field–induced strain in lead-free piezoceramics." Science 378, no. 6624 (December 9, 2022): 1125–30. http://dx.doi.org/10.1126/science.ade2964.

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Piezoelectric actuators are indispensable over a wide range of industries for their fast response and precise displacement. Most commercial piezoelectric actuators contain lead, posing environmental challenges. We show that a giant strain (1.05%) and a large-signal piezoelectric strain coefficient (2100 picometer/volt) are achieved in strontium (Sr)–doped (K,Na)NbO 3 lead-free piezoceramics, being synthesized by the conventional solid-state reaction method without any post treatment. The underlying mechanism responsible for the ultrahigh electrostrain is the interaction between defect dipoles and domain switching. The fatigue resistance, thermal stability, and strain value (0.25%) at 20 kilovolt/centimeter are comparable with or better than those of commercial Pb(Zr,Ti)O 3 -based ceramics, showing great potential for practical applications. This material may provide a lead-free alternative with a simple composition for piezoelectric actuators and a paradigm for the design of high-performance piezoelectrics.

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Maiwa, Hiroshi. "Electromechanical Properties of Ferroelectric Thin Films for Piezoelectric MEMS Applications." Advances in Science and Technology 45 (October 2006): 2422–31. http://dx.doi.org/10.4028/www.scientific.net/ast.45.2422.

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Piezoelectric microelectromechanical systems (MEMS) employing ferrroelectric thin films have been extensively studied. In this paper, materials issues of the piezoeletric films are presented. Temperature dependence of the electrical and electromechanical properties of Pb(ZrxTi1-x)O3 (PZT, x= 0.3, 0.52, and 0.7) thin films were measured using scanning probe microscopy in the temperature range from -100°C to 150°C. The field-induced displacement increased with increase of the temperature; however, their temperature dependence was relatively small, compared with that reported on bulk PZT ceramics. Thus far, the use of PZT film has been most widely studied for MEMS applications. However, the lead toxicity associated with PZT and other lead oxide-based ferroelectrics is problematic. Therefore, properties of the lead-free thin film piezoelectrics are also described in this paper. As candidate for the lead-free piezoelectrics, Bi4-xNdxTi3O12 (BNT) and Ba(Zr0.2Ti0.8)O3 (BZT) thin films are chosen. BNT and BZT films prepared by chemical solution deposition exhibit field-induced strain corresponding to 38 pm/V and 35 pm/V, respectively.

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Cao, Hong Xia, Chuang Zhang, Qing Quan Liu, and You Bao Wang. "Elastomechanical Study of Magnetoeletric Coupling in Bilayer of Lithium Zinc Ferrite and Lead Zirconate Titanate." Advanced Materials Research 602-604 (December 2012): 813–20. http://dx.doi.org/10.4028/www.scientific.net/amr.602-604.813.

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A theoretical model based on the constitutive equations of piezoelectrics and magnetostrictor is introduced to discuss the magnetoelectric (ME) coupling in freebody bilayer containing magnetostrictive and piezoelectric phases. The ME coupling at low frequency of Ni0.8Zn0.2Fe2O4–PZT bilayer have been studied by using the model and the corresponding material parameters of individual phases. The results show that the ME voltage coefficients can increase to a maximum at a given volume fraction of piezoelectric phase. An approximately linear increase of the maximum has been obtained with strengthening interface coupling. Analysis shows that large magnetostriction, appropriate volume fraction and ideal interface coupling are key ingredients for obtaining excellent ME performance.

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9

Uchino, Kenji. "Piezoelectric Devices in the Sustainable Society." Sustainability in Environment 4, no. 4 (September 11, 2019): p181. http://dx.doi.org/10.22158/se.v4n4p181.

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Our 21st century faces to a “sustainable society”, which enhances (a) usage of non-toxic materials, (b) disposal technology for existing hazardous materials, (c) reduction of contamination gas, (d) environmental monitoring system, (e) new energy source creation, and (f) energy-efficient device development in the piezoelectric area. With reducing their size, the electromagnetic components reduce their efficiency drastically. Thus, piezoelectric transducers with much less losses are highly sought recently. Piezoelectric devices seem to be all-around contributors and a key component to the above mentioned five R&D areas. Some of the efforts include: (a) Since the most popular piezoelectric lead zirconate titante ceramics will be regulated in European and Asian societies due to their toxicity (Pb2+ ion), lead-free piezoelectrics have been developed. (b) Since hazardous organic substances can easily be dissolved by the ultrasonic irradiation in water, a new safe disposal technology using piezoelectric transducers has been developed. (c) We demonstrated an energy recovery system on a hybrid car from its engine’s mechanical vibration to the rechargeable battery. (d) Micro ultrasonic motors based on piezoelectrics demonstrated 1/20 reduction in the volume and a 20-time increase in efficiency of the conventional electromagnetic motors. This paper introduces leading piezoelectric materials, devices, and drive/control methods, relating with the above “sustainability” technologies, aiming at further research expansion in this area.

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Li, Bin Zhi, Chris Fancher, John E. Blendell, R. Edwin Garcia, and Keith J. Bowman. "Ferroelastic Domains and Anisotropy in Lead Free Piezoelectrics." Materials Science Forum 702-703 (December 2011): 995–98. http://dx.doi.org/10.4028/www.scientific.net/msf.702-703.995.

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Our research investigates the correlations between domain texture and microstructural features, including crystallographic texture in bulk and thin film polycrystalline materials to understand the development of piezoelectric and other anisotropic properties in a number of rapidly evolving lead free piezoelectric materials. We investigate approaches to understanding polarization distributions by starting from polarization measurements. In addition, 2D and 3D microstructural simulations are carried out in all types of ferroelectrics to rationalize and then engineer their equilibrium and kinetic response. This paper discusses recent findings associated with bulk piezoelectricity, phase stability, and ferroelastic and ferroelectric domain motion for materials such as Ba(Ti0.8Zr0.2)O3-x(Ba0.7Ca0.3)TiO3 (BZT-BCT) and Bi0.5Na0.5TiO3 (BNT). Conventional and synchrotron-based x-ray diffraction, electron and optical microscopy and piezoelectric characterization techniques are employed to assess texture, both as a function of poling and temperature. The coupling between microstructure and the inherent directional biases fundamental to piezoelectric and ferroelectric performance enable consideration of orientation and anisotropy in systems with unique constraints.

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11

Esquivel-Gaon, Margarita, Sergio Anguissola, David Garry, Adriana del C. Gallegos-Melgar, Juan Muñoz Saldaña, Kenneth A. Dawson, Andrea De Vizcaya-Ruiz, and Luz M. Del Razo. "Bismuth-based nanoparticles as the environmentally friendly replacement for lead-based piezoelectrics." RSC Advances 5, no. 35 (2015): 27295–304. http://dx.doi.org/10.1039/c5ra02151k.

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12

Miriyala, Kumaraswamy, and Ranjith Ramadurai. "Microstructural influence on piezoresponse and leakage current behavior of Na0.5Bi0.5TiO3 Thin Films." MRS Advances 1, no. 37 (2016): 2597–602. http://dx.doi.org/10.1557/adv.2016.350.

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AbstractSodium bismuth titanate (Na0.5Bi0.5TiO3: NBT) a lead free piezoelectric; exhibits promising features such that it could be an alternate to lead based piezoelectrics. In this work, we report the microstructural influence on piezoelectric and leakage current behavior of NBT thin films grown by pulsed laser ablation (PLD). Various microstructural features like coarse faceted grains and fine spherical grains was achieved by effective optimization of substrate temperature and oxygen partial pressures. The studies reveals that, leakage current of NBT thin films were dominated by interface limited modified Schottky emission type of conduction. The piezoelectric domain studies reveal that for NBT thin films with fine spherical grain the domain pattern was highly dominated by the morphology and in the case of coarse faceted grains the domains were relatively large and the domains were extending beyond the grain boundaries.

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13

Patrick, Chris. "Just how giant is “giant” electrostriction?" Scilight 2022, no. 18 (May 6, 2022): 181110. http://dx.doi.org/10.1063/10.0010487.

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14

Zhang, Binyu, Jiagang Wu, Xiaojing Cheng, Xiaopeng Wang, Dingquan Xiao, Jianguo Zhu, Xiangjian Wang, and Xiaojie Lou. "Lead-free Piezoelectrics Based on Potassium–Sodium Niobate with Giant d33." ACS Applied Materials & Interfaces 5, no. 16 (August 12, 2013): 7718–25. http://dx.doi.org/10.1021/am402548x.

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15

Zhang, Su‐Wei, Zhen Zhou, Jin Luo, and Jing‐Feng Li. "Potassium‐Sodium‐Niobate‐Based Thin Films: Lead Free for Micro‐Piezoelectrics." Annalen der Physik 531, no. 7 (March 12, 2019): 1800525. http://dx.doi.org/10.1002/andp.201800525.

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Lim, Jong Bong, Danilo Suvorov, and Jae-Ho Jeon. "Ferroelectric Bi(Na,K)TiO3-based materials for lead-free piezoelectrics." Ceramics International 38 (January 2012): S355—S358. http://dx.doi.org/10.1016/j.ceramint.2011.05.011.

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17

Park, D. S., M. Hadad, L. M. Riemer, R. Ignatans, D. Spirito, V. Esposito, V. Tileli, et al. "Induced giant piezoelectricity in centrosymmetric oxides." Science 375, no. 6581 (February 11, 2022): 653–57. http://dx.doi.org/10.1126/science.abm7497.

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Piezoelectrics are materials that linearly deform in response to an applied electric field. As a fundamental prerequisite, piezoelectric materials must have a noncentrosymmetric crystal structure. For more than a century, this has remained a major obstacle for finding piezoelectric materials. We circumvented this limitation by breaking the crystallographic symmetry and inducing large and sustainable piezoelectric effects in centrosymmetric materials by the electric field–induced rearrangement of oxygen vacancies. Our results show the generation of extraordinarily large piezoelectric responses [with piezoelectric strain coefficients ( d 33 ) of ~200,000 picometers per volt at millihertz frequencies] in cubic fluorite gadolinium-doped CeO 2− x films, which are two orders of magnitude larger than the responses observed in the presently best-known lead-based piezoelectric relaxor–ferroelectric oxide at kilohertz frequencies. These findings provide opportunities to design piezoelectric materials from environmentally friendly centrosymmetric ones.

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Matzen, S., S. Gable, N. Lequet, S. Yousfi, K. Rani, T. Maroutian, G. Agnus, H. Bouyanfif, and P. Lecoeur. "High piezoelectricity in epitaxial BiFeO₃ microcantilevers." Applied Physics Letters 121, no. 14 (October 3, 2022): 142901. http://dx.doi.org/10.1063/5.0105404.

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The large switchable ferroelectric polarization and lead-free composition of BiFeO3 make it a promising candidate as an active material in numerous applications, in particular, in micro-electro-mechanical systems (MEMS) when BiFeO3 is integrated in a thin film form on a silicon substrate. Here, 200-nm-thick Mn-doped BiFeO3 thin films have been epitaxially grown on a SrRuO3/SrTiO3/Si substrate and patterned into microcantilevers as prototype device structures for piezoelectric actuation. The devices demonstrate excellent ferroelectric response with a remanent polarization of 55 μC/cm2. The epitaxial BiFeO3 MEMS exhibit very high piezoelectric response with transverse piezoelectric coefficient d31 reaching 83 pm/V. The BiFeO3 cantilevers show larger electromechanical performance (the ratio of curvature/electric field) than that of state-of-art piezoelectric cantilevers, including well-known PZT (Pb(Zr,Ti)O3) and the hyper-active PMN–PT (Pb(Mg1/3Nb2/3)O3-PbTiO3). In addition, the piezoelectricity in BiFeO3 MEMS is found to depend on the ferroelectric polarization direction, which could originate from the flexoelectric effect and be exploited to further enhance the electromechanical performance of the devices. These results could potentially lead to a replacement of lead-based piezoelectrics by BiFeO3 in many microdevices.

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Yang, Hao, Jinyan Zhao, Wei Ren, Zuo-Guang Ye, K. B. Vinayakumar, Rosana A. Dias, Rui M. R. Pinto, Jian Zhuang, and Nan Zhang. "Lead free 0.9Na_1/2Bi_1/2TiO₃–0.1BaZr_0.2Ti_0.8O₃ thin film with large piezoelectric electrostrain." Applied Physics Letters 121, no. 13 (September 26, 2022): 132903. http://dx.doi.org/10.1063/5.0106934.

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A sodium bismuth titanate-based thin film is widely investigated lead-free piezoelectrics with potential applications for modern micro-devices such as PiezoMEMS. In this work, a 0.9Na1/2Bi1/2TiO3–0.1BaZr0.2Ti0.8O3 thin film was deposited on a Pt/Ti/SiO2/Si (001) substrate by the sol–gel spin coating method. The deposited piezoelectric film shows low dielectric loss and high remnant polarization. The measured ferroelectricity loop showed a coercive field of 110 kV/cm and a saturation polarization of 46.83 μC/cm2. The piezoelectric response of this thin film does not decrease from room temperature to around 100 °C. The fabricated piezoelectric device with bottom and top electrodes showed a large macro-scale strain value of ∼4% under the DC (30 V) and AC voltages (f = 800 kHz, Vpp = 10 V).

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Zhang, Qiwei, Ke Chen, Leilei Wang, Haiqin Sun, Xusheng Wang, and Xihong Hao. "A highly efficient, orange light-emitting (K0.5Na0.5)NbO3:Sm3+/Zr4+ lead-free piezoelectric material with superior water resistance behavior." Journal of Materials Chemistry C 3, no. 20 (2015): 5275–84. http://dx.doi.org/10.1039/c4tc02995j.

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21

Zhang, Shujun, Ru Xia, and Thomas R. Shrout. "Modified (K0.5Na0.5)NbO3 based lead-free piezoelectrics with broad temperature usage range." Applied Physics Letters 91, no. 13 (September 24, 2007): 132913. http://dx.doi.org/10.1063/1.2794400.

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Rangel, Renato, José Sobrinho, Alan Silva, Cícero Souto, and Andreas Ries. "Double Beam Energy Harvester Based on PZT Piezoelectrics." European Journal of Engineering Research and Science 5, no. 12 (December 1, 2020): 1–10. http://dx.doi.org/10.24018/ejers.2020.5.12.2240.

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This work presents a new design and performance evaluation of an energy harvester. The generator was built in the form of a double beam mechanical structure on which eight piezoelectric elements were glued and subjected to cyclic tensile and compression loads. Electrical energy is converted from mechanical vibrations generated by machines, by means of a piezoelectric material based on Lead Zirconium Titanate (PZT). Geometric dimensions of the beam structure were optimized by a finite element analysis prior to the practical construction of the device. Simulated and experimental results regarding the generator dynamics and the generated electric voltage are presented and compared. The device was evaluated for different excitations and vibration amplitudes at a frequency of 60 Hz in order to capture vibrational energy from machines at this frequency. Additionally, the generator's performance was evaluated when operating under two different real-world conditions: First, the device mounted on a condenser of an air conditioner, then on a three-phase motor pump. As a load for the piezoelectric generator, an RF circuit transmitted the ambient temperature information to a nearby computer. Correct reception of the ambient temperature value validated the ability to generate electrical power suitable for a low-power circuit. As contribution to the literature, this study demonstrates the ability of a novel piezoelectric generator design, to provide sufficient power for a circuit transmitting information from a sensor. This allows monitoring the state of a machine, using energy dissipated by mechanical vibrations in order to power the electronic systems responsible for sensing.

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Rangel, Renato, José Sobrinho, Alan Silva, Cícero Souto, and Andreas Ries. "Double Beam Energy Harvester Based on PZT Piezoelectrics." European Journal of Engineering and Technology Research 5, no. 12 (December 1, 2020): 1–10. http://dx.doi.org/10.24018/ejeng.2020.5.12.2240.

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This work presents a new design and performance evaluation of an energy harvester. The generator was built in the form of a double beam mechanical structure on which eight piezoelectric elements were glued and subjected to cyclic tensile and compression loads. Electrical energy is converted from mechanical vibrations generated by machines, by means of a piezoelectric material based on Lead Zirconium Titanate (PZT). Geometric dimensions of the beam structure were optimized by a finite element analysis prior to the practical construction of the device. Simulated and experimental results regarding the generator dynamics and the generated electric voltage are presented and compared. The device was evaluated for different excitations and vibration amplitudes at a frequency of 60 Hz in order to capture vibrational energy from machines at this frequency. Additionally, the generator's performance was evaluated when operating under two different real-world conditions: First, the device mounted on a condenser of an air conditioner, then on a three-phase motor pump. As a load for the piezoelectric generator, an RF circuit transmitted the ambient temperature information to a nearby computer. Correct reception of the ambient temperature value validated the ability to generate electrical power suitable for a low-power circuit. As contribution to the literature, this study demonstrates the ability of a novel piezoelectric generator design, to provide sufficient power for a circuit transmitting information from a sensor. This allows monitoring the state of a machine, using energy dissipated by mechanical vibrations in order to power the electronic systems responsible for sensing.

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Berksoy, Ayse, and Ebru Mensur Alkoy. "Preperation of Lead-Free Potassium Sodium Niobate Based Piezoelectrics and their Electromechanical Characteristics." Advanced Materials Research 445 (January 2012): 492–96. http://dx.doi.org/10.4028/scientific5/amr.445.492.

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Berksoy, Ayse, and Ebru Mensur Alkoy. "Preperation of Lead-Free Potassium Sodium Niobate Based Piezoelectrics and their Electromechanical Characteristics." Advanced Materials Research 445 (January 2012): 492–96. http://dx.doi.org/10.4028/www.scientific.net/amr.445.492.

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In this study, %7 Li modified and 0.67 % copper oxide added potassium sodium niobate (KNN) ceramics were investigated. Copper oxide was used as a sintering aid. The ceramics were prepared with conventional solid state calcination technique. All samples were crystallized in pure perovskite phase with no additional peak. The density of the samples increased with copper addition and lithium modification. The Curie temperature of KNN ceramics was found to shift to lower temperatures by CuO addition. The Curie temperature was measured as 414°C and 504°C for copper oxide added and lithium modified KNN samples, respectively. The maximum strain of copper oxide added sample was 0.12%, whereas Li modified KL ceramics yielded up to 0.10 %.

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Ullah, Aman, Chang Won Ahn, Amir Ullah, and Ill Won Kim. "Large strain under a low electric field in lead-free bismuth-based piezoelectrics." Applied Physics Letters 103, no. 2 (July 8, 2013): 022906. http://dx.doi.org/10.1063/1.4813420.

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Chen, Feng, Yuan-Hang Li, Guan-Yin Gao, Fang-Zhou Yao, Ke Wang, Jing-Feng Li, Xiao-Long Li, Xing-Yu Gao, and Wenbin Wu. "Intergranular Stress Induced Phase Transition in CaZrO3 Modified KNN-Based Lead-Free Piezoelectrics." Journal of the American Ceramic Society 98, no. 4 (January 21, 2015): 1372–76. http://dx.doi.org/10.1111/jace.13461.

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Mishra, Anupam, Dipak Kumar Khatua, Gobinda Das Adhikary, Naveen Kumar, Uma Shankar, and Rajeev Ranjan. "Finite-size-effect on a very large length scale in NBT-based lead-free piezoelectrics." Journal of Advanced Dielectrics 09, no. 05 (October 2019): 1950035. http://dx.doi.org/10.1142/s2010135x19500358.

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[Formula: see text][Formula: see text]TiO3-based lead-free piezoelectrics are considered for potential replacement of the lead-based commercial piezoceramics in high-power transducer applications. We have examined the role of grain size in influencing the structural-polar inhomogeneity of stoichiometric and off-stoichiometric [Formula: see text][Formula: see text]TiO3 (NBT), and its morphotropic-phase-boundary (MPB) derivative 0.94[Formula: see text][Formula: see text]TiO3-0.06BaTiO3 (NBT-6BT). Our study reveals that size effect comes into play in these systems on a very large length scale (on the scale of microns) considerably affecting its global structure and properties.

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Liu, Qing, Yichi Zhang, Jing Gao, Zhen Zhou, Dong Yang, Kai-Yang Lee, Andrew Studer, et al. "Practical high-performance lead-free piezoelectrics: structural flexibility beyond utilizing multiphase coexistence." National Science Review 7, no. 2 (November 5, 2019): 355–65. http://dx.doi.org/10.1093/nsr/nwz167.

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Abstract Due to growing concern for the environment and human health, searching for high-performance lead-free piezoceramics has been a hot topic of scientific and industrial research. Despite the significant progress achieved toward enhancing piezoelectricity, further efforts should be devoted to the synergistic improvement of piezoelectricity and its thermal stability. This study provides new insight into these topics. A new KNN-based lead-free ceramic material is presented, which features a large piezoelectric coefficient (d33) exceeding 500 pC/N and a high Curie temperature (Tc) of ∼200°C. The superior piezoelectric response strongly relies on the increased composition-induced structural flexibility due to lattice softening and decreased unit cell distortion. In contrast to piezoelectricity anomalies induced via polymorphic transition, this piezoelectricity enhancement is effective within a broad temperature range rather than a specific small range. In particular, a hierarchical domain architecture composed of nano-sized domains along the submicron domains was detected in this material system, which further contributes to the high piezoelectricity.

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Mahajan, Amit, Hangfeng Zhang, Jiyue Wu, E. Venkata Ramana, M. J. Reece, and Haixue Yan. "Effect of Phase Transitions on Thermal Depoling in Lead-Free 0.94(Bi0.5Na0.5TiO3)–0.06(BaTiO3) Based Piezoelectrics." Journal of Physical Chemistry C 121, no. 10 (March 6, 2017): 5709–18. http://dx.doi.org/10.1021/acs.jpcc.6b12501.

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Serrazina, Ricardo, Camila Ribeiro, Maria Elisabete Costa, Luis Pereira, Paula M. Vilarinho, and Ana M. O. R. Senos. "Particle Characteristics’ Influence on FLASH Sintering of Potassium Sodium Niobate: A Relationship with Conduction Mechanisms." Materials 14, no. 5 (March 9, 2021): 1321. http://dx.doi.org/10.3390/ma14051321.

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The considerable decrease in temperature and time makes FLASH sintering a more sustainable alternative for materials processing. FLASH also becomes relevant if volatile elements are part of the material to be processed, as in alkali-based piezoelectrics like the promising lead-free K0.5Na0.5NbO3 (KNN). Due to the volatile nature of K and Na, KNN is difficult to process by conventional sintering. Although some studies have been undertaken, much remains to be understood to properly engineer the FLASH sintering process of KNN. In this work, the effect of FLASH temperature, TF, is studied as a function of the particle size and impurity content of KNN powders. Differences are demonstrated: while the particle size and impurity degree markedly influence TF, they do not significantly affect the densification and grain growth processes. The conductivity of KNN FLASH-sintered ceramics and KNN single crystals (SCs) is compared to elucidate the role of particles’ surface conduction. When particles’ surfaces are not present, as in the case of SCs, the FLASH process requires higher temperatures and conductivity values. These results have implications in understanding FLASH sintering towards a more sustainable processing of lead-free piezoelectrics.

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Vasileva, Daria, Semen Vasilev, Andrei L. Kholkin, and Vladimir Ya Shur. "Domain Diversity and Polarization Switching in Amino Acid β-Glycine." Materials 12, no. 8 (April 15, 2019): 1223. http://dx.doi.org/10.3390/ma12081223.

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Piezoelectric materials based on lead zirconate titanate are widely used in sensors and actuators. However, their application is limited because of high processing temperature, brittleness, lack of conformal deposition and, more importantly, intrinsic incompatibility with biological environments. Recent studies on bioorganic piezoelectrics have demonstrated their potential in these applications, essentially due to using the same building blocks as those used by nature. In this work, we used piezoresponse force microscopy (PFM) to study the domain structures and polarization reversal in the smallest amino acid glycine, which recently attracted a lot of attention due to its strong shear piezoelectric activity. In this uniaxial ferroelectric, a diverse domain structure that includes both 180° and charged domain walls was observed, as well as domain wall kinks related to peculiar growth and crystallographic structure of this material. Local polarization switching was studied by applying a bias voltage to the PFM tip, and the possibility to control the resulting domain structure was demonstrated. This study has shown that the as-grown domain structure and changes in the electric field in glycine are qualitatively similar to those found in the uniaxial inorganic ferroelectrics.

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Maqbool, Adnan, Ali Hussain, Rizwan Ahmed Malik, Jamil Ur Rahman, Arif Zaman, Tae Kwon Song, Won-Jeong Kim, and Myong-Ho Kim. "Evolution of phase structure and giant strain at low driving fields in Bi-based lead-free incipient piezoelectrics." Materials Science and Engineering: B 199 (September 2015): 105–12. http://dx.doi.org/10.1016/j.mseb.2015.05.009.

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Hao, Jigong, Zhijun Xu, Ruiqing Chu, Wei Li, and Juan Du. "Effect of (Bi0.5K0.5)TiO3 on the electrical properties, thermal and fatigue behavior of (K0.5Na0.5)NbO3-based lead-free piezoelectrics." Journal of Materials Research 30, no. 13 (June 23, 2015): 2018–29. http://dx.doi.org/10.1557/jmr.2015.169.

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Takesue, Naohisa, and Jun-ichi Saito. "Molecular Orbital Calculation of Lead-Free Perovskite Compounds for Efficient Use of Alkaline and Alkaline Earth Metals." Crystals 10, no. 11 (October 22, 2020): 956. http://dx.doi.org/10.3390/cryst10110956.

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The effective ionic charges of lead-free perovskite dielectric complex compounds were investigated with molecular orbital calculation. The base model was a double perovskite cluster that consisted of octahedral oxygen cages with a transition metal ion of titanium, niobium, or zirconium located at each of their centers, and alkali and/or alkaline earth metal ions located at the body center, corners, edge centers, or face centers of the cluster. The results showed significant covalent bonds between the transition metals and the oxygens, and the alkali metals, especially sodium and oxygen. On the other hand, the alkaline earth metals have weak covalency. Calculation was also performed with the replacement of some of the oxygens with chlorine or fluorine; such replacement enhances the covalency of the transition metals. These trends provide good guidelines for the design properties of lead-free perovskite piezoelectrics based on ubiquitous sodium use.

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Patel, Satyanarayan, Kodumudi Venkataraman Lalitha, and Nishchay Saurabh. "Enhanced Pyroelectric Performance of Lead-Free Zn-Doped Na1/2Bi1/2TiO3-BaTiO3 Ceramics." Materials 15, no. 1 (December 23, 2021): 87. http://dx.doi.org/10.3390/ma15010087.

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Lead-free Na1/2Bi1/2TiO3-BaTiO3 (NBT-BT) has gained revived interest due to its exceptionally good high power properties in comparison to commercial lead-based piezoelectrics. Recently, Zn-modified NBT-BT-based materials as solid solution and composites have been reported to exhibit enhanced depolarization temperatures and a high mechanical quality factor. In this work, the pyroelectric properties of Zn-doped NBT-6mole%BT and NBT-9mole%BT ceramics are investigated. The doped compositions of NBT-6BT and NBT-9BT feature a relatively stable pyroelectric property in a wide temperature range of ~37 K (300–330 K) and 80 K (300–380 K), respectively. A threefold increase in detector figure of merit is noted for 0.01 mole Zn-doped NBT-6mole% BT at room temperature in comparison to undoped NBT-6mole%BT and this increase is higher than those of major lead-free materials. A broad range of the temperature-independent behavior for the figures of merit was noted (303–380 K) for Zn-doped NBT-6mole% BT, which is 30 K higher than the undoped material. The large pyroelectric figures of merit and good temperature stability renders Zn-doped NBT-BT an ideal candidate for pyroelectric detector and energy harvesting applications.

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Cheng, Xiaojing, Jiagang Wu, Xiaopeng Wang, Binyu Zhang, Jianguo Zhu, Dingquan Xiao, Xiangjian Wang, and Xiaojie Lou. "Giant d33 in (K,Na)(Nb,Sb)O3-(Bi,Na,K, Li)ZrO3 based lead-free piezoelectrics with high Tc." Applied Physics Letters 103, no. 5 (July 29, 2013): 052906. http://dx.doi.org/10.1063/1.4817517.

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Kim, Sangwook, Hyunwook Nam, Ichiro Fujii, Shintaro Ueno, Chikako Moriyoshi, Yoshihiro Kuroiwa, and Satoshi Wada. "A-site cation off-centering contribution on ferroelectricity and piezoelectricity in pseudo-cubic perovskite structure of Bi-based lead-free piezoelectrics." Scripta Materialia 205 (December 2021): 114176. http://dx.doi.org/10.1016/j.scriptamat.2021.114176.

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Adhikary, Gobinda Das, Dipak Kumar Khatua, Anatoliy Senyshyn, and Rajeev Ranjan. "Long-period structural modulation on the global length scale as the characteristic feature of the morphotropic phase boundaries in the Na0.5Bi0.5TiO3 based lead-free piezoelectrics." Acta Materialia 164 (February 2019): 749–60. http://dx.doi.org/10.1016/j.actamat.2018.11.016.

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Rafiq, M. A., M. E. Costa, I. M. Reaney, and P. M. Vilarinho. "Transmission Electron Microscopy of Mn-doped KNN Ceramics." Microscopy and Microanalysis 19, S4 (August 2013): 99–100. http://dx.doi.org/10.1017/s1431927613001116.

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Smart materials like piezoelectrics and ferroelectrics play a crucial role in applications such assensors and actuators,radio-frequency switching, drug delivery, chemicals detection, and power generation and storage. K0.5Na0.5NbO3 (KNN) is one of the leading lead free piezoelectric materials being considered as an alternativeto Pb(Zrx,Ti1-x)O3 (PZT), which is currently the most widely used material for electromechanical applications. Although pure KNN has inferior electromechanical properties compared to PZT,efforts are on going to tailor and improve its piezoelectric coefficients by doping and texturing.Although the piezoelectric constant (d33) of undoped KNN is unsuitable for practical electromechanical applications, properties comparable to PZT at room temperature (d33>400 pC/N) have been reported for modified KNN ceramics. Electromechanical properties are however, very much dependent on the crystalline phase content, crystallographic orientation, microstructure, interfaces and domain configuration.Mn is an indispensable dopant for both PbO-based as well as PbO-free ceramics like BaTiO3, SrTiO3, KNbO3 and KTaO3. It has been reported to improve the density, mechanical quality factor, electromechanical properties and to reduce dielectric loss. Mn has been successfully used to reduce the leakage current and lower the orthorhombic to tetragonal phase transition temperature (TO-T) in KNN single crystals. It has also been shown to improve the density and properties of KNN–LiTaO3–LiSbO3. However, the effect of Mn on the KNN domain structure and phase assemblage has not yet been reported. In this work, KNN ceramics doped with Mn on the B-site (Mn content was 0.5, 1.0. 1.5 and 2 mole%) were synthesized by a conventional mixed oxide method. Transmission electron microscopy (TEM)(Hitachi 9000) studies were carried out to analyse the effect of B-site Mn doping on the ferroelectric domain structure and phase assemblage.Undoped KNN ceramics had large grains (>30 >m) which contained large (>1 >m wide) wedge shaped ferroelectric domains. KNN doped with 0.5 mole % Mn exhibited a smaller grain size (~2 mm) in which a well defined domain structure was observed with widths approximately an order of magnitude smaller than those in undoped KNN. For KNN doped with 2 mole % Mn, the presence of a second phase, Figure 1c, was often observed. Electron diffraction patterns from the second phase were consistent with a tetragonal tungsten bronze (TTB) structured compound although more work is required to definitively determine the phase assemblage. The domain structure became increasing complex as Mn concentration increased, suggesting that the presence of Mn on the B-site disrupts polar order.In conclusion, TEM analysis demonstrated that Mn doping changes the domain structure of KNN ceramics: for low Mn content, well defined ferroelectric domains and for high Mn content, tangled domains and second phase were the main features.These microstructure details elucidate reasons that may account for the inferior piezoelectric properties of KNN at higher Mn concentration.

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Pang, Qianyi, Lanruo Han, and Xiang Yu. "Doping modification in lead-free piezoelectric ceramics." Highlights in Science, Engineering and Technology 55 (July 9, 2023): 166–75. http://dx.doi.org/10.54097/hset.v55i.9952.

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Piezoelectric ceramics are functional information ceramic materials that can convert mechanical and electrical energy into each other. They are widely used in high-tech fields, such as the electronics industry, machinery, and aerospace. Currently, Pb(ZrTi)O3 (PZT) piezoelectric materials are most commonly used, but the main component, PbO, is toxic and volatile during production and manufacturing, thus causing certain damage to human health and the environment. Therefore, research on green and environmentally friendly lead-free piezoelectric materials has been attracting much attention. This paper will therefore present two lead-free piezoelectric ceramics that have the potential to replace PZT-based lead-containing piezoelectric materials: Potassium Sodium Niobate (KNN)-based piezoelectric ceramics and Bismuth Sodium Titanate (BNT)-based lead-free piezoelectric ceramics. The piezoelectric constants of lead-free piezoelectric ceramics represented by systems such as KNN and BNT are now comparable to those of lead-containing piezoelectric ceramics and are gradually replacing traditional lead-based piezoelectric ceramics in fields such as ultrasonic atomization and hydroacoustic energy transfer.

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Bajpai, Parmendra Kumar. "Dielectric Relaxation Phenomena in some Lead and Non-Lead Based Ferroelectric Relaxor Materials: Recent Advances." Solid State Phenomena 189 (June 2012): 233–66. http://dx.doi.org/10.4028/www.scientific.net/ssp.189.233.

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Relaxors with general formula AA'BB'O3with different cationic distributions at A/B-sites have important device applications in capacitors, piezoelectric ultrasonic transducers, electrostrictive actuators, SAW substrates, etc. The doping or compositional changes in these ceramics can control the high electromechanical characteristics. Lead zirconate titanates (PZT) - based solid solutions exhibit excellent electrochemical properties and are widely used as actuators, transducers, ceramic filters, resonators, sensors and other electronic devices, due to their excellent piezoelectric properties. Although, there has been a concerted effort to develop leadfree piezoelectric ceramics, no effective alternative to PZT has yet been found; most other materials that possess high dielectric and piezoelectric coefficients still contain lead ions. Dielectric relaxation in these materials is of fundamental importance. Recently, new relaxor ferroelectric materials (Pb (B1/3Nb2/3)O3types) have been reported by our group in which the dielectric relaxation character is different from that observed in typical lead based relaxors. In the first part of the review, relaxor characteristics, strategies to synthesize phase pure lead based relaxors and dielectric relaxation phenomena are presented. Deviation of the frequency dependent susceptibility from Curie-Weiss law is analysed both in terms of Gaussian and Lorentzian formalisms. Lead based ferroelectric relaxor materials, due to environmental, health and social reasons are not preferred in devices and attempts are being made to eliminate the lead content from these materials. Sodium bismuth titanate (Na0.5Bi0.5TiO3, abbreviated as NBT), is considered to be one of the excellent candidates for lead-free piezoelectric material. However, pure NBT piezoelectric ceramics are difficult to pole due to its relatively large coercive field and high electrical conductivity. Therefore, many solid solutions of NBT with other ceramics are proposed to improve the relevant properties. In the second part of the review, relaxor behaviour of newly developed solid solutions of NBT is discussed. Finally, the future scope of research on these advance materials is presented.

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Quan, Ngo Duc, Luong Huu Bac, Duong Van Thiet, Vu Ngoc Hung, and Dang Duc Dung. "Current Development in Lead-FreeBi0.5(Na,K)0.5TiO3-Based Piezoelectric Materials." Advances in Materials Science and Engineering 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/365391.

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The lead-free piezoelectric ceramics display good piezoelectric properties which are comparable with Pb(Zr,Ti)O3(PZT) and these materials overcome the hazard to the environment and human health. The Bi0.5(Na,K)0.5TiO3(BNKT) is rapidly developed because of good piezoelectric, ferroelectric, and dielectric properties compared to PZT. The origin of giant strain of BNKT piezoelectric materials was found at morphotropic phase boundary due to crystal change from tetragonal to orthorhombic and/or precipitation of cubic phases, in addition to domain switching mechanism. The dopants or secondary phases withABO3structure as solid solution are expected to change the crystal structure and create the vacancies which results in enhancement of the piezoelectric properties. In this work, we reviewed the current development of BNKT by dopants and secondary phase as solid solution. Our discussion will focus on role of dopants and secondary phase to piezoelectric properties of BNKT. This result will open the direction to control the properties of lead-free piezoelectric materials.

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Choi, Jin-Hong, Hyun-Ah Kim, Seung-Ho Han, Hyung-Won Kang, Hyeung-Gyu Lee, Jeong-Seog Kim, and Chae-Il Cheon. "BiFeO3-based Lead-free Piezoelectric Ceramics." Journal of the Korean Institute of Electrical and Electronic Material Engineers 25, no. 9 (September 1, 2012): 692–701. http://dx.doi.org/10.4313/jkem.2012.25.9.692.

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Baek, Changyeon, Hyeonbin Park, Jong Hyuk Yun, Do Kyung Kim, and Kwi-Il Park. "Lead-free BaTiO3 Nanowire Arrays-based Piezoelectric Energy Harvester." MRS Advances 2, no. 56 (2017): 3415–20. http://dx.doi.org/10.1557/adv.2017.305.

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ABSTRACTVertically aligned BaTiO3 nanowire (NW) arrays on a Ti substrate were adopted for use in piezoelectric energy harvesting device that scavenges electricity from mechanical energy. BaTiO3 NWs were simultaneously grown at the top and bottom surfaces of a Ti substrate by two-step hydrothermal process. To characterized the piezoelectric output performance of the individual NW, we transferred a BaTiO3 single NW that was selected from well-aligned NW arrays onto a flexible substrate and measured the electric signals during the bending/unbending motions. For fabricating a piezoelectric energy harvester (PEH), both NW arrays were sandwiched between two transparent indium tin oxide (ITO)-coated polyethylene terephthalate (PET) plastic films and then packaged with polydimethylsiloxane (PDMS) elastomer. A lead-free BaTiO3 NW array-based PEH produced an output voltage of about 90 V and a maximum current of 1.2 μA under periodically bending motions.

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Kim, Seung-Hyun, Alice Leung, Eun Young Lee, Lindsay Kuhn, Wenyan Jiang, Dong-Joo Kim, and Angus I. Kingon. "Non-Lead Based Piezoelectric Thin Films: Materials and Energy Harvesting Device." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2011, CICMT (September 1, 2011): 000033–36. http://dx.doi.org/10.4071/cicmt-2011-ta14.

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Non-lead based piezoelectric thin films of (K,Na)(Nb,Ta)O3–BiFeO3 (NKNT-BF) were successfully fabricated by the chemical solution deposition method. Small concentration of BF (5 mol %) added into NKNT films led to a fully dense microstructure and enhanced dielectric and piezoelectric properties compared to pure NKNT films. The measured dielectric constant and piezoelectric d33 values were around 575 and 50 pC/N, respectively. A thin film NKNT-BF piezoelectric cantilever with a micromachined Si proof mass was fabricated for a low frequency vibration energy harvesting device. The average power and the power density of NKNT-BF energy harvesting cantilever with the device volume of 0.007 cm3 were 1.82 μW and 260 μW/cm3 at the resonance frequency of 130 Hz and the acceleration of 0.75 G. Even if these values were somewhat inferior to those of the conventional PZT energy harvesting device, NKNT-BF thin film provided the promising results as an alternative material of PZT for the piezoelectric MEMS applications in the future.

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Dong, Nannan, Xiaoyi Gao, Fangquan Xia, Hanxing Liu, Hua Hao, and Shujun Zhang. "Dielectric and Piezoelectric Properties of Textured Lead-Free Na0.5Bi0.5TiO3-Based Ceramics." Crystals 9, no. 4 (April 14, 2019): 206. http://dx.doi.org/10.3390/cryst9040206.

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This work provides a comparative study of the dielectric and piezoelectric properties of randomly oriented and textured 0.88Na0.5Bi0.5TiO3-0.08K0.5Bi0.5TiO3-0.04BaTiO3 (88NBT) ceramics. Textured ceramics were fabricated by template grain growth (TGG) method using NaNbO3 (NN) for templates. For textured ceramics with 4 wt% NN templates, a Lotgering factor of 96% and piezoelectric coefficient d33 of 185 pC/N were obtained. Compared to the randomly oriented ceramics, textured ceramics show lower strain hysteresis (H = 7.6%), higher unipolar strain of 0.041% with corresponding large signal piezoelectric coefficient d33* of 200 pm/V at applied field of 2 kV/mm. This enhancement can be explained by the grain orientation along <001> direction by texturing, where an engineered domain configuration is formed after polarization, leading to decreased hysteresis and increased piezoelectric property.

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Quan, Yi, Chunlong Fei, Wei Ren, Lingyan Wang, Jinyan Zhao, Jian Zhuang, Tianlong Zhao, et al. "Single-Beam Acoustic Tweezer Prepared by Lead-Free KNN-Based Textured Ceramics." Micromachines 13, no. 2 (January 25, 2022): 175. http://dx.doi.org/10.3390/mi13020175.

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Acoustic tweezers for microparticle non-contact manipulation have attracted attention in the biomedical engineering field. The key components of acoustic tweezers are piezoelectric materials, which convert electrical energy to mechanical energy. The most widely used piezoelectric materials are lead-based materials. Because of the requirement of environmental protection, lead-free piezoelectric materials have been widely researched in past years. In our previous work, textured lead-free (K, Na)NbO3 (KNN)-based piezoelectric ceramics with high piezoelectric performance were prepared. In addition, the acoustic impedance of the KNN-based ceramics is lower than that of lead-based materials. The low acoustic impedance could improve the transmission efficiency of the mechanical energy between acoustic tweezers and water. In this work, acoustic tweezers were prepared to fill the gap between lead-free piezoelectric materials research and applications. The tweezers achieved 13 MHz center frequency and 89% −6 dB bandwidth. The −6 dB lateral and axial resolution of the tweezers were 195 μm and 114 μm, respectively. Furthermore, the map of acoustic pressure measurement and acoustic radiation calculation for the tweezers supported the trapping behavior for 100 μm diameter polystyrene microspheres. Moreover, the trapping and manipulation of the microspheres was achieved. These results suggest that the KNN-based acoustic tweezers have a great potential for further applications.

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Gross, S. J., S. Tadigadapa, T. N. Jackson, S. Trolier-McKinstry, and Q. Q. Zhang. "Lead-zirconate-titanate-based piezoelectric micromachined switch." Applied Physics Letters 83, no. 1 (July 7, 2003): 174–76. http://dx.doi.org/10.1063/1.1589192.

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Shin, Dong-Jin, Woo-Seok Kang, Dong-Hwan Lim, Bo-Kun Koo, Min-Soo Kim, Soon-Jong Jeong, and In-Sung Kim. "Lead-Free AE Sensor Based on BZT–BCT Ceramics." Sensors 21, no. 21 (October 26, 2021): 7100. http://dx.doi.org/10.3390/s21217100.

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In this study, an acoustic emission (AE) sensor was fabricated using lead-free Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 (BZT–BCT) ceramics. The acoustic and electromechanical properties of the AE sensor were determined by the shapes of the piezoelectric ceramics. To optimize the AE sensor performance, the shapes of the ceramics were designed according to various diameter/thickness ratios (D/T) = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0. The BZT–BCT ceramic with D/T = 1.0 exhibited excellent values of a piezoelectric charge coefficient (d33), piezoelectric voltage coefficient (g33), and electromechanical coupling factor (kp), which were 370 (pC/N), 11.3 (10−3 Vm/N), and 0.58, respectively. Optimum values of resonant frequency (fr) = 172.724 (kHz), anti-resonant frequency (fa) = 196.067 (kHz), and effective electromechanical coupling factor (keff) = 0.473 were obtained for the manufactured BZT–BCT ceramic with D/T = 1.0. The maximum sensitivity and frequency of the AE sensor made of the BZT–BCT ceramic with a D/T ratio of 1.0 were 65 dB and 30 kHz, respectively.

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Journal articles on the topic 'Lead based Piezoelectrics'

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