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Research Articles|148 Article(s)
Structure and dielectric properties of (1-x)Na
E. V. Glazunova, L. A. Shilkina, A. S. Chekhova, A. V. Nazarenko, I. A. Verbenko, and L. A. Reznichenko
The solid solutions of the (1-x)Na0.5Bi0.5TiO3-xNa0.5K0.5NbO3 system were produced by the conventional ceramic technology using mechanical activation of the synthesized product. It was found that in the (1-x)Na0.5Bi0.5TiO3-xNa0.5K0.5NbO3 system at room temperature, a number of morphotropic phase transitions occur: rhombohedral → cubic → tetragonal → monoclinic phases. The introduction of a small amount of Na0.5K0.5NbO3 leads to an increase in the temperature stability of the dielectric properties of ceramics. A change in the relaxor properties of the solid solutions of the (1-x)Na0.5Bi0.5TiO3-xNa0.5K0.5NbO3 system was shown. The increase in energy density and energy efficiency was found at additive 10mol.% of Na0.5K0.5NbO3. The solid solutions of the (1-x)Na0.5Bi0.5TiO3-xNa0.5K0.5NbO3 system were produced by the conventional ceramic technology using mechanical activation of the synthesized product. It was found that in the (1-x)Na0.5Bi0.5TiO3-xNa0.5K0.5NbO3 system at room temperature, a number of morphotropic phase transitions occur: rhombohedral → cubic → tetragonal → monoclinic phases. The introduction of a small amount of Na0.5K0.5NbO3 leads to an increase in the temperature stability of the dielectric properties of ceramics. A change in the relaxor properties of the solid solutions of the (1-x)Na0.5Bi0.5TiO3-xNa0.5K0.5NbO3 system was shown. The increase in energy density and energy efficiency was found at additive 10mol.% of Na0.5K0.5NbO3.
Journal of Advanced Dielectrics
- Publication Date: Jan. 01, 2024
- Vol. 14, Issue 1, 2350023 (2024)
Substitution of Pb with (Li
Binzhi Liu, Anand P. S. Gaur, Jun Cui, and Xiaoli Tan
PbZrO3-based antiferroelectric (AFE) ceramics are promising dielectrics for high-energy-density capacitors due to their reversible phase transitions during charge–discharge cycles. In this work, a new composition series, [Pb0.93−xLa0.02(Li1∕2Bi1∕2)xSr0.04][Zr0.57Sn0.34Ti0.09]O3, with Li+ and Bi3+ substitution of Pb2+ at x=0, 0.04, 0.08, 0.12, 0.16 is investigated for the microstructure evolution, ferroelectric (FE) and dielectric properties. It is found that Li+ and Bi3+ substitution can significantly reduce the sintering temperature and simultaneously enhance the dielectric breakdown strength. An ultrahigh energy efficiency (94.0%) and a large energy density (3.22J/cm3) are achieved in the composition of x=0.12 with a low sintering temperature (1075∘C). PbZrO3-based antiferroelectric (AFE) ceramics are promising dielectrics for high-energy-density capacitors due to their reversible phase transitions during charge–discharge cycles. In this work, a new composition series, [Pb0.93−xLa0.02(Li1∕2Bi1∕2)xSr0.04][Zr0.57Sn0.34Ti0.09]O3, with Li+ and Bi3+ substitution of Pb2+ at x=0, 0.04, 0.08, 0.12, 0.16 is investigated for the microstructure evolution, ferroelectric (FE) and dielectric properties. It is found that Li+ and Bi3+ substitution can significantly reduce the sintering temperature and simultaneously enhance the dielectric breakdown strength. An ultrahigh energy efficiency (94.0%) and a large energy density (3.22J/cm3) are achieved in the composition of x=0.12 with a low sintering temperature (1075∘C).
Journal of Advanced Dielectrics
- Publication Date: Jan. 01, 2024
- Vol. 14, Issue 1, 2350022 (2024)
Dielectric spectroscopy characterization of Na
Georgi B. Hadjichristov, Daniela G. Kovacheva, Yordan G. Marinov, Daniela B. Karashanova, Todor E. Vlakhov, and Nicola Scaramuzza
We studied the effect of titanium dioxide (TiO2) nanoparticles (NPs) on dielectric behavior of Na+ ion-conducting salt-complexed polymer nanocomposite system formed from a binary polymer blend of poly(ethylene oxide) (PEO) and polyvinyl pyrrolidone (PVP), with the addition of both sodium metaperiodate (NaIO4) at concentration 10wt.% and TiO2 NPs of size ∼10nm, at concentrations 1, 2, 3, 4 and 5wt.%. Free standing nanocomposite PEO/PVP/NaIO4/TiO2 films (150μm) were characterized at room-temperature by analyzing their complex electrical impedance and dielectric spectra in the range 1Hz–1MHz. At the concentration of 3wt.% of TiO2 NPs, both ion conductivity and dielectric permittivity of the PEO/PVP/NaIO4/TiO2 ion-conducting dielectrics reach an enhancement by more than one order of magnitude as compared to nanoadditive-free case. We studied the effect of titanium dioxide (TiO2) nanoparticles (NPs) on dielectric behavior of Na+ ion-conducting salt-complexed polymer nanocomposite system formed from a binary polymer blend of poly(ethylene oxide) (PEO) and polyvinyl pyrrolidone (PVP), with the addition of both sodium metaperiodate (NaIO4) at concentration 10wt.% and TiO2 NPs of size ∼10nm, at concentrations 1, 2, 3, 4 and 5wt.%. Free standing nanocomposite PEO/PVP/NaIO4/TiO2 films (150μm) were characterized at room-temperature by analyzing their complex electrical impedance and dielectric spectra in the range 1Hz–1MHz. At the concentration of 3wt.% of TiO2 NPs, both ion conductivity and dielectric permittivity of the PEO/PVP/NaIO4/TiO2 ion-conducting dielectrics reach an enhancement by more than one order of magnitude as compared to nanoadditive-free case.
Journal of Advanced Dielectrics
- Publication Date: Jan. 01, 2024
- Vol. 14, Issue 1, 2350021 (2024)
Optimization design of autofocusing metasurface for ultrasound wave application
Zhaoxi Li, Shenghui Yang, Mengqing Zhou, Chenxue Hou, Dongdong Chen, Chunlong Fei, Di Li, Yi Quan, and Yintang Yang
In this paper, two optimized autofocusing metasurfaces (AFMs) with different desired focal distances are designed by using particle swarm optimization (PSO) algorithm. Based on the finite element simulation software COMSOL Multiphysics, the performance of ultrasound transducer (UT) with AFM at different design parameters in Airy distributions (r0,ω) and the bottom thickness (d) of AFM are simulated and analyzed. Based on the simulation data, the artificial neural network model is trained to describe the complex relationship between the design parameters of AFM and the performance parameters of UT. Then, the multiobjective optimization function for AFM is determined according to the desired performance parameters of UT, including focal position, lateral resolution, longitudinal resolution and absolute sound pressure. In order to obtain AFMs with the desired performance, PSO algorithm is adopted to optimize the design parameters of AFM according to the multiobjective optimization function, and two AFMs are optimized and fabricated. The experimental results well agree with the simulation and optimization results, and the optimized AFMs can achieve the desired performance. The fabricated AFM can be easily integrated with UT, which has great potential applications in wave field modulation underwater, acoustic tweezers, biomedical imaging, industrial nondestructive testing and neural regulation. In this paper, two optimized autofocusing metasurfaces (AFMs) with different desired focal distances are designed by using particle swarm optimization (PSO) algorithm. Based on the finite element simulation software COMSOL Multiphysics, the performance of ultrasound transducer (UT) with AFM at different design parameters in Airy distributions (r0,ω) and the bottom thickness (d) of AFM are simulated and analyzed. Based on the simulation data, the artificial neural network model is trained to describe the complex relationship between the design parameters of AFM and the performance parameters of UT. Then, the multiobjective optimization function for AFM is determined according to the desired performance parameters of UT, including focal position, lateral resolution, longitudinal resolution and absolute sound pressure. In order to obtain AFMs with the desired performance, PSO algorithm is adopted to optimize the design parameters of AFM according to the multiobjective optimization function, and two AFMs are optimized and fabricated. The experimental results well agree with the simulation and optimization results, and the optimized AFMs can achieve the desired performance. The fabricated AFM can be easily integrated with UT, which has great potential applications in wave field modulation underwater, acoustic tweezers, biomedical imaging, industrial nondestructive testing and neural regulation.
Journal of Advanced Dielectrics
- Publication Date: Jan. 01, 2024
- Vol. 14, Issue 1, 2350001 (2024)
Preparation and acoustic properties of high-temperature acoustic emission sensor based on La3Ga5SiO
Jingxiang Si, Changhong Yang, Rui Guo, Yifan Wu, Xiujuan Lin, and Shifeng Huang
With the rapid development of modern industries, the high-temperature piezoelectric sensors that can work in extreme environments are in great demand. In this work, langasite (La3Ga5SiO14, LGS), as a high-temperature piezoelectric crystal with stable electro-elastic performance, is used as core element, and air and porous Al2O3 are selected as backing layers respectively to prepare two kinds of high-temperature acoustic emission (AE) sensors. The detection sensitivities at 25–500∘C are analyzed by the ball falling test and Hsu–Nielsen experiment. Under the condition of 25–500∘C, the received amplitude signals by both sensors are maintained above 90dB stimulated by the ZrO2 ceramic ball dropping. In the Hsu–Nielsen experiment, as the temperature rising from 25∘C to 500∘C, the signal amplitude of sensor with air backing layer decays from 447mV to 365mV, while the signal amplitude varies from 270mV to 203mV for the sensor with porous Al2O3 backing layer. Significantly, compared with the bandwidth of the air-backing sensor (37–183kHz), the sensor with porous Al2O3 backing layer broadens bandwidth to 28–273kHz. These results show that both these AE sensors have strong and stable response ability to AE signals at high-temperature of 500∘C. Therefore, piezoelectric AE sensor based on LGS has great potential application in the field of high-temperature structural health monitoring. With the rapid development of modern industries, the high-temperature piezoelectric sensors that can work in extreme environments are in great demand. In this work, langasite (La3Ga5SiO14, LGS), as a high-temperature piezoelectric crystal with stable electro-elastic performance, is used as core element, and air and porous Al2O3 are selected as backing layers respectively to prepare two kinds of high-temperature acoustic emission (AE) sensors. The detection sensitivities at 25–500∘C are analyzed by the ball falling test and Hsu–Nielsen experiment. Under the condition of 25–500∘C, the received amplitude signals by both sensors are maintained above 90dB stimulated by the ZrO2 ceramic ball dropping. In the Hsu–Nielsen experiment, as the temperature rising from 25∘C to 500∘C, the signal amplitude of sensor with air backing layer decays from 447mV to 365mV, while the signal amplitude varies from 270mV to 203mV for the sensor with porous Al2O3 backing layer. Significantly, compared with the bandwidth of the air-backing sensor (37–183kHz), the sensor with porous Al2O3 backing layer broadens bandwidth to 28–273kHz. These results show that both these AE sensors have strong and stable response ability to AE signals at high-temperature of 500∘C. Therefore, piezoelectric AE sensor based on LGS has great potential application in the field of high-temperature structural health monitoring.
Journal of Advanced Dielectrics
- Publication Date: Jan. 01, 2024
- Vol. 14, Issue 1, 2342001 (2024)
Flexoelectricity in oxide thin films
Guoyang Shen, Renhong Liang, Zhiguo Wang, Zhiyong Liu, and Longlong Shu
Flexoelectric effect describes the electromechanical coupling between the strain gradient and its internal polarization in all dielectrics. Despite this universality, the resulting flexoelectric field remains small at the macroscopic level. However, in nanosystems, the size-dependent effect of flexoelectricity becomes increasingly significant, leading to a notable flexoelectric field that can strongly influence the material’s physical properties. This review aims to explore the flexoelectric effect specifically at the nanoscale. We achieve this by examining strain gradients generated through two distinct methods: internal inhomogeneous strain and external stimulation. In addition, advanced synthesis techniques are utilized to enhance the properties and functionalities associated with flexoelectricity. Furthermore, we delve into other coupled phenomena observed in thin films, including the coupling and utilization of flexomagnetic and flexophotovoltaic effects. This review presents the latest advancements in these areas and highlights their role in driving further breakthroughs in the field of flexoelectricity. Flexoelectric effect describes the electromechanical coupling between the strain gradient and its internal polarization in all dielectrics. Despite this universality, the resulting flexoelectric field remains small at the macroscopic level. However, in nanosystems, the size-dependent effect of flexoelectricity becomes increasingly significant, leading to a notable flexoelectric field that can strongly influence the material’s physical properties. This review aims to explore the flexoelectric effect specifically at the nanoscale. We achieve this by examining strain gradients generated through two distinct methods: internal inhomogeneous strain and external stimulation. In addition, advanced synthesis techniques are utilized to enhance the properties and functionalities associated with flexoelectricity. Furthermore, we delve into other coupled phenomena observed in thin films, including the coupling and utilization of flexomagnetic and flexophotovoltaic effects. This review presents the latest advancements in these areas and highlights their role in driving further breakthroughs in the field of flexoelectricity.
Journal of Advanced Dielectrics
- Publication Date: Jan. 01, 2024
- Vol. 14, Issue 1, 2330001 (2024)
Investigation of electrophysical, photo- and gas-sensitive properties of ZnO–SnO2 sol–gel films
Irina A. Gulyaeva, Alexandra P. Ivanisheva, Maria G. Volkova, Victoria Yu. Storozhenko, Soslan A. Khubezhov, Ekaterina M. Bayan, and Victor V. Petrov
Thin nanocomposite films based on tin dioxide with a low content of zinc oxide (0.5–5mol.%) were obtained by the sol–gel method. The synthesized films are 300–600nm thick and contains pore sizes of 19–29nm. The resulting ZnO–SnO2 films were comprehensively studied by atomic force and Kelvin probe force microscopy, X-ray diffraction, scanning electron microscopy, and high-resolution X-ray photoelectron spectroscopy spectra. The photoconductivity parameters on exposure to light with a wavelength of 470nm were also studied. The study of the photosensitivity kinetics of ZnO–SnO2 films showed that the film with the Zn:Sn ratio equal to 0.5:99.5 has the minimum value of the charge carrier generation time constant. Measurements of the activation energy of the conductivity, potential barrier, and surface potential of ZnO–SnO2 films showed that these parameters have maxima at ZnO concentrations of 0.5mol.% and 1mol.%. Films with 1mol.% ZnO exhibit high response values when exposed to 5–50ppm of nitrogen dioxide at operating temperatures of 200∘C and 250∘C. Thin nanocomposite films based on tin dioxide with a low content of zinc oxide (0.5–5mol.%) were obtained by the sol–gel method. The synthesized films are 300–600nm thick and contains pore sizes of 19–29nm. The resulting ZnO–SnO2 films were comprehensively studied by atomic force and Kelvin probe force microscopy, X-ray diffraction, scanning electron microscopy, and high-resolution X-ray photoelectron spectroscopy spectra. The photoconductivity parameters on exposure to light with a wavelength of 470nm were also studied. The study of the photosensitivity kinetics of ZnO–SnO2 films showed that the film with the Zn:Sn ratio equal to 0.5:99.5 has the minimum value of the charge carrier generation time constant. Measurements of the activation energy of the conductivity, potential barrier, and surface potential of ZnO–SnO2 films showed that these parameters have maxima at ZnO concentrations of 0.5mol.% and 1mol.%. Films with 1mol.% ZnO exhibit high response values when exposed to 5–50ppm of nitrogen dioxide at operating temperatures of 200∘C and 250∘C.
Journal of Advanced Dielectrics
- Publication Date: Jan. 01, 2024
- Vol. 14, Issue 1, 2245002 (2024)
Energy storage optimization of ferroelectric ceramics during phase-transition process of amorphous/nanocrystalline and polycrystalline by using a phase-field model for dielectric breakdown
Suilong Huang, Jianwen Chen, Zhen Su, Xiucai Wang, Wenbo Zhu, Wenjun Chen, Xinmei Yu, and Peng Xiao
Ferroelectric ceramics have the potential to be widely applied in the modern industry and military power systems due to their ultrafast charging/discharging speed and high energy density. Considering the structural design and electrical properties of ferroelectric capacitor, it is still a challenge to find out the optimal energy storage of ferroelectric ceramics during the phase-transition process of amorphous/nanocrystalline and polycrystalline. In this work, a finite element model suitable for the multiphase ceramic system is constructed based on the phase field breakdown theory. The nonlinear coupling relationship of multiple physical fields between multiphase ceramics was taken into account in this model. The basic structures of multiphase ceramics are generated by using the Voronoi diagram construction method. The specified structure of multiphase ceramics in the phase-transition process of amorphous/nanocrystalline and polycrystalline was further obtained through the grain boundary diffusion equation. The simulation results show that the multiphase ceramics have an optimal energy storage in the process of amorphous polycrystalline transformation, and the energy storage density reaches the maximum when the crystallinity is 13.96% and the volume fraction of grain is 2.08%. It provides a research plan and idea for revealing the correlation between microstructure and breakdown characteristics of multiphase ceramics. This simulation model realizes the nonlinear coupling of the multiphase ceramic mesoscopic structure and the phase field breakdown. It provides a reference scheme for the structural design and performance optimization of ferroelectric ceramics. Ferroelectric ceramics have the potential to be widely applied in the modern industry and military power systems due to their ultrafast charging/discharging speed and high energy density. Considering the structural design and electrical properties of ferroelectric capacitor, it is still a challenge to find out the optimal energy storage of ferroelectric ceramics during the phase-transition process of amorphous/nanocrystalline and polycrystalline. In this work, a finite element model suitable for the multiphase ceramic system is constructed based on the phase field breakdown theory. The nonlinear coupling relationship of multiple physical fields between multiphase ceramics was taken into account in this model. The basic structures of multiphase ceramics are generated by using the Voronoi diagram construction method. The specified structure of multiphase ceramics in the phase-transition process of amorphous/nanocrystalline and polycrystalline was further obtained through the grain boundary diffusion equation. The simulation results show that the multiphase ceramics have an optimal energy storage in the process of amorphous polycrystalline transformation, and the energy storage density reaches the maximum when the crystallinity is 13.96% and the volume fraction of grain is 2.08%. It provides a research plan and idea for revealing the correlation between microstructure and breakdown characteristics of multiphase ceramics. This simulation model realizes the nonlinear coupling of the multiphase ceramic mesoscopic structure and the phase field breakdown. It provides a reference scheme for the structural design and performance optimization of ferroelectric ceramics.
Journal of Advanced Dielectrics
- Publication Date: Jan. 01, 2024
- Vol. 14, Issue 1, 2245001 (2024)
Author Index (Volume 13)
Journal of Advanced Dielectrics
- Publication Date: Jan. 01, 2023
- Vol. 13, Issue 6, 2399001 (2023)
Creation of periodical domain structure by local polarization reversal in planar waveguide produced by soft proton exchange in LiNbO3
Evgeniy Savelyev, Andrey Akhmatkhanov, Boris Slautin, Hervé Tronche, Florent Doutre, Tommaso Lunghi, Pascal Baldi, and Vladimir Shur
The paper presents the results of an experimental study of the local polarization reversal and creation of domains by a biased tip of scanning probe microscope (SPM) in lithium niobate single crystals of congruent composition with a surface layer modified by soft proton exchange (SPE). The depth dependence of H+ ions concentration in the SPE-modified layer measured by confocal Raman microscopy demonstrates a sufficient composition gradient. The creation of isolated domains and stripe domain structures has been done by two switching modes: (1) point switching by field application in separated points and (2) line scanning switching by motion of the biased tip being in contact with the sample surface. For point switching for pulse durations less than 10s, the logarithmic dependence of the domain diameter on the pulse duration was observed. The change of the dependence to a linear one for pulse duration above 10s has been attributed to the transition from the stochastic step generation at the domain wall to the deterministic one at the domain vertexes. The periodical structure of stripe domains was created in SPE CLN planar waveguides by scanning at elevated temperature. The revealed switching regime suppresses electrostatic interaction of neighboring domains and leads to a significant improvement of the domain structure regularity. The creation of the stable periodical domain structure with submicron periods in SPE CLN planar waveguides was demonstrated. The paper presents the results of an experimental study of the local polarization reversal and creation of domains by a biased tip of scanning probe microscope (SPM) in lithium niobate single crystals of congruent composition with a surface layer modified by soft proton exchange (SPE). The depth dependence of H+ ions concentration in the SPE-modified layer measured by confocal Raman microscopy demonstrates a sufficient composition gradient. The creation of isolated domains and stripe domain structures has been done by two switching modes: (1) point switching by field application in separated points and (2) line scanning switching by motion of the biased tip being in contact with the sample surface. For point switching for pulse durations less than 10s, the logarithmic dependence of the domain diameter on the pulse duration was observed. The change of the dependence to a linear one for pulse duration above 10s has been attributed to the transition from the stochastic step generation at the domain wall to the deterministic one at the domain vertexes. The periodical structure of stripe domains was created in SPE CLN planar waveguides by scanning at elevated temperature. The revealed switching regime suppresses electrostatic interaction of neighboring domains and leads to a significant improvement of the domain structure regularity. The creation of the stable periodical domain structure with submicron periods in SPE CLN planar waveguides was demonstrated.
Journal of Advanced Dielectrics
- Publication Date: Jan. 01, 2023
- Vol. 13, Issue 6, 2350020 (2023)
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