20,517 results on '"FERROELECTRICITY"'
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2. Study of Di-/Ferro-/Piezoelectric Properties of Sm3+-Doped ZnO Nanoparticles.
- Author
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Verma, Radha, Goel, Sahil, Verma, Komal, Kant, Krishan, Kumar, Rajesh, Garg, Maneesha, and Gupta, Rashi
- Subjects
DIELECTRIC loss ,STRAY currents ,PERMITTIVITY ,STRAINS & stresses (Mechanics) ,ENERGY density - Abstract
Pristine ZnO and Sm-doped ZnO nanoparticles were synthesized using a wet chemical co-precipitation technique. The morphological and structural characteristics of pristine and Sm-doped ZnO were studied by field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) techniques. Increases in lattice parameters, interplanar spacing, and volume was observed from the XRD patterns compared to its JCPDS card. Crystallite size, dislocation density, deformation stress, lattice strain, and energy density for both pristine and Sm-ZnO nanoparticles were calculated using Scherrer and Williamson–Hall (W–H) methods. An energy bandgap reduction was observed in the Sm-doped ZnO (E
g ~ 2.7 eV), which played a crucial role in explaining the increased leakage currents in Sm-ZnO. The Sm-doped ZnO nanoparticles exhibited a remnant polarization (Pr ~ 0.163 µC/cm2 ) and a coercive field (Ec ~ 25.33 kV/cm). Current–voltage (I–V) characteristics show maximum current generated on applying varying voltages (Vmax = 40 V, Imax = ~600 μA). Frequency- and temperature-dependent dielectric studies were conducted to examine the change in the values of the dielectric constant and dielectric loss with the variation in frequency and temperature. The Sm-doped ZnO-based nanogenerator generated an output voltage ~ 400 mV at tapping force of ~ 0.02 kgf, which makes it a prominent candidate for self-powered devices. [ABSTRACT FROM AUTHOR]- Published
- 2025
- Full Text
- View/download PDF
3. Study of Di-/Ferro-/Piezoelectric Properties of Sm3+-Doped ZnO Nanoparticles
- Author
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Verma, Radha, Goel, Sahil, Verma, Komal, Kant, Krishan, Kumar, Rajesh, Garg, Maneesha, and Gupta, Rashi
- Published
- 2025
- Full Text
- View/download PDF
4. Dielectric and Electrical Behavior of Apraseodymium Based Tungsten Bronze Ceramics.
- Author
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Devi, Saraswati, Behera, Saubhagyalaxmi, Moharana, Srikanta, Chakroborty, Subhendu, and Barik, Arundhati
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- *
TUNGSTEN bronze , *THERMISTORS , *DIELECTRICS , *HIGH temperature electronics , *FERROELECTRIC materials , *OXIDE ceramics , *PARTICLE size distribution - Abstract
The ceramic oxide Na2Ba2Pr2W2Ti4Nb4O30 (NBPWTN) is prepared by a mechanical mixed oxide route. The compound formation and the phase are concluded from the x‐ray diffraction pattern taken at room temperature (XRD). The uniform distribution of grains of various sizes with negligible voids is studied from scanning electron micrograph of the sample pellet. The presence of dielectric dispersion and ferroelectric phase in the material is observed from the temperature‐dependent dielectric parameters at selected frequencies. The existence of ferroelectricity in the material is further confirmed by the room temperature hysteresis loop. Impedance spectroscopic studies informed about the correlation between the microstructure and electrical behavior. The frequency variation of AC conductivity refers to Jonscher's law. The temperature variation of frequency exponent term n indicates OLPT (overlapping large polaron‐tunneling) model of the conduction mechanism in the sample. NBPWTN is a strong candidate for applications involving thermistor‐related devices because of the temperature dependency of resistance. The value of temperature sensitivity coefficient β in our investigation is achieved between 2000 and 11 000 K, confirming that the material has a high‐temperature stability property and is ideal for high‐temperature electronics applications. The high room temperature dielectric constant value of the ceramic (around 500) is useful for dielectric capacitor applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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5. A (Ba0.94Ca0.06)(Ti0.95Zr0.05)O3 ceramic sheet doping to improve the inverse piezoelectric effect of the poly (vinylidene fluoride‐trifluoroethylene)‐based composite film
- Author
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Ping, Yufan, Xia, Weimin, Zhou, Jiahong, Zhang, Xiaofang, and Li, Zhong
- Subjects
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PIEZOELECTRICITY , *PERMITTIVITY , *PIEZOELECTRIC composites , *FERROELECTRIC polymers , *FERROELECTRICITY , *ELECTRIC fields , *LEAD zirconate titanate - Abstract
A lead‐free tetragonal‐phase (Ba0.94Ca0.06)(Ti0.95Zr0.05)O3 (BCTZ) micro sheet is prepared by molten‐salt growth method, which exhibits a polarizing behavior of relaxor ferroelectricity and possesses a high dielectric constant (εr) of ~2400. Subsequently, the BCTZ sheet is evenly doped into ferroelectric copolymer P(VDF‐TrFE)55/45 mol% with different mass fractions, and the flexible BCTZ/P(VDF‐TrFE) composite films are prepared using a conventional solution casting process. εr of BCTZ/P(VDF‐TrFE) increases with the mass content of BCTZ, and reaches 23.8 in 20 wt% BCTZ sample. Meanwhile, at a high electrical field of 30 MV/m, the strain and electric field of BCTZ/P(VDF‐TrFE) are in the opposite direction, indicating a negative value of piezoelectric strain coefficient (d33) caused by inverse piezoelectric effect. In addition, d33 of different BCTZ/P(VDF‐TrFE) films are fitted using a strain‐electrical field curve, which firstly increases and then decreases with increases in BCTZ content. As such, a high d33 of −47.3 pC/N is obtained in BCTZ/P(VDF‐TrFE)15/85 wt% film. Thus, this research concerning the inverse piezoelectric effect may provide a reference for designing a piezoelectric composite using in transducers and actuators. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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6. Enhanced Ferroelectric and Dielectric Properties in Bi0.5Na0.5TiO3 Doped with BaTiO3 (BNT-BT) Nanoparticles for High Energy Storage Device.
- Author
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Kumari, Manju, Dhariwal, Neeraj, Yadav, Preety, Kumar, Vinod, and Thakur, O. P.
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DIELECTRIC properties ,FERROELECTRICITY ,BARIUM titanate ,NANOPARTICLES ,ENERGY storage - Abstract
Nanoparticles of lead-free Bi
0.5 Na0.5 TiO3 doped with BaTiO3 (BNT-BT) have been fabricated by the auto-combustion sol-gel method. A structural and morphological analysis of the developed material has been performed by using XRD and FESEM. Also, a temperature and frequency (100Hz-1MHz) dependent dielectric study of BNT-BT nanoparticles has been conducted, resulting in a variation that occurs at 120.83 °C due to transition from ferroelectric to antiferroelectric phase, followed by a sudden increase due to paraelectric phase formation. Additionally, as frequency increased, the dielectric constant decreased exhibiting Maxwell-Wagner polarization. The ferroelectric study has been done by using PE loop at room temperature (28 °C). The maximum value obtained for remanent polarization and saturation polarization is 1.73 µC/cm² and 3.75 µC/cm² respectively at an applied electric field of 28 kV/cm. The value for the recoverable energy storage density (W1 ) is 0.0483 J/cm³, energy loss density(W2 ) is 0.05378 J/cm³ and and its efficiency (η) is 47% at an applied field 28 kV/cm. The obtained results for the BNT-BT nanoparticles are remarkable for energy storage devices, and they further indicate their potential for energy harvesting and high piezoelectric sensors for industrial purposes. [ABSTRACT FROM AUTHOR]- Published
- 2023
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7. Yttrium Doping Effects on Ferroelectricity and Electric Properties of As-Deposited Hf 1−x Zr x O 2 Thin Films via Atomic Layer Deposition.
- Author
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Oh, Youkyoung, Lee, Seung Won, Choi, Jeong-Hun, Ahn, Seung-Eon, Kim, Hyo-Bae, and Ahn, Ji-Hoon
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ATOMIC layer deposition , *THIN films , *FERROELECTRICITY , *ELECTRIC properties , *FERROELECTRIC thin films , *YTTRIUM , *LEAD titanate , *FERROELECTRIC devices - Abstract
Hf1−xZrxO2 (HZO) thin films are versatile materials suitable for advanced ferroelectric semiconductor devices. Previous studies have shown that the ferroelectricity of HZO thin films can be stabilized by doping them with group III elements at low concentrations. While doping with Y improves the ferroelectric properties, there has been limited research on Y-HZO thin films fabricated using atomic layer deposition (ALD). In this study, we investigated the effects of Y-doping cycles on the ferroelectric and electrical properties of as-deposited Y-HZO thin films with varying compositions fabricated through ALD. The Y-HZO thin films were stably crystallized without the need for post-thermal treatment and exhibited transition behavior depending on the Y-doping cycle and initial composition ratio of the HZO thin films. These Y-HZO thin films offer several advantages, including enhanced dielectric constant, leakage current density, and improved endurance. Moreover, the optimized Y-doping cycle induced a phase transformation that resulted in Y-HZO thin films with improved ferroelectric properties, exhibiting stable behavior without fatigue for up to 1010 cycles. These as-deposited Y-HZO thin films show promise for applications in semiconductor devices that require high ferroelectric properties, excellent electrical properties, and reliable performance with a low thermal budget. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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8. Structural evolution and coexistence of ferroelectricity and antiferromagnetism in Fe, Nb co-doped BaTiO3 ceramics.
- Author
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Hu, Zimeng, Koval, Vladimir, Yue, Yajun, Zhang, Man, Jia, Chenglong, Abrahams, Isaac, and Yan, Haixue
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CERAMICS , *FERROELECTRIC ceramics , *ANTIFERROMAGNETISM , *FERROELECTRICITY , *BARIUM titanate , *DOPING agents (Chemistry) , *MAGNETIC hysteresis - Abstract
Multiferroics are materials that exhibit two or more primary ferroic properties within the same phase and have potential applications in sensors, spintronics and memory devices. Here, the dielectric, ferroelectric and magnetic properties of novel multiferroics derived from BaTi 1− x (Fe 0.5 Nb 0.5) x O 3 (BTFN, 0.01 ≤ x ≤ 0.10) ceramics are investigated. Multiferroism in these ceramics is manifested by the coexistence of ferroelectric long-range ordering and antiferromagnetism. With increasing x -value, there is a structural evolution from a tetragonal perovskite to a mixture of tetragonal and cubic phases, accompanied by a decrease in the temperature of maximum permittivity. At room temperature, ferroelectric behaviour is evidenced by the presence of current peaks corresponding to domain switching in the current-electric field loops, while the observation of non-linear narrow magnetic hysteresis loops suggests dilute magnetism. The results indicate that in the x = 0.07 composition the antiferromagnetic order is established through an indirect super-exchange interaction between adjacent Fe ions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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9. Comprehensive analysis of ferroelectric, piezoelectric, mechanical, and nonlinear optical properties of imidazolium d-camphorsulfonate single crystals.
- Author
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Bhardwaj, Simran, Kumar, Pradeep, Jha, Ranjana, and Yadav, Harsh
- Subjects
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FRONTIER orbitals , *SINGLE crystals , *CRYSTAL growth , *MICROHARDNESS testing , *X-ray powder diffraction - Abstract
Single crystals of imidazolium d -camphorsulfonate (D-ImCS) are synthesized through the slow evaporation solution method. Powder X-ray diffraction reveals that the grown crystals have crystallized in the monoclinic phase with non-centrosymmetric space group P2 1. UV–visible spectroscopy measurements showed that D-ImCS crystals only absorb in the UV region. Photoluminescence studies indicated emissions in the blue and violet regions. The functional groups present in the crystal were identified through FTIR analysis. The soft nature of the crystal was identified using Vicker's microhardness testing. Dielectric analysis reveals the transition temperature T c = 365.7 K. The piezoelectric charge constant (d 22) is determined to be ±8 pC N−1. The polarization hysteresis loop demonstrates the ferroelectric nature. The presence of NLO property is demonstrated through SHG. Density Functional Theory (DFT) utilizing Gaussian 16 W software provided the optimized structure, UV–visible absorbance, FTIR spectra, frontier molecular orbitals, density of states, molecular electrostatic potential, atomic charge distribution, natural population analysis and non-linear optical properties (NLO). This computational approach complements and validates experimental findings, resulting in a thorough knowledge of D-ImCS behavior and properties. [Display omitted] • D-ImCS single crystals are grown through the solution method. • PE loop shows high saturation polarization and coercive electric field. • Vicker's microhardness testing shows that D-ImCS is a soft crystal. • SHG demonstrates NLO activity of D-ImCS single crystal. • HOMO-LUMO, MEP, NBO, NLO, FTIR and UV absorbance spectrum via DFT. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. Effect of dopant on ferroelectric, dielectric and photocatalytic properties of Co–La-doped dysprosium chromite prepared via microemulsion route.
- Author
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Maqbool, Humaira, Bibi, Ismat, Nazeer, Zarish, Majid, Farzana, Ata, Sadia, Raza, Qasim, Iqbal, Munawar, Slimani, Yassine, Khan, M.I., and Fatima, Mahvish
- Subjects
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FERROELECTRICITY , *DIELECTRIC properties , *DYSPROSIUM , *CHROMITE , *GENTIAN violet , *MICROEMULSIONS , *SILVER phosphates , *DOPING agents (Chemistry) - Abstract
In the current study, pristine and a series of La and Co-doped dysprosium chromite (Dy 1-y La y Cr 1-x Co x O 3) nanoparticles have been fabricated via a facile microemulsion technique. The influence of doping was evaluated based on structural, ferroelectric, dielectric, and photocatalytic properties. The prepared nanoparticles were characterized by XRD, SEM, Raman, and UV–Vis techniques. XRD patterns confirm the synthesis of a monophase orthorhombic structure with space group Pbnm with an average crystalline size in the 18–37 nm range. The saturation polarization (Ps), remanence (Pr), and coercivity (Hc) were determined using a hysteresis loop, and it was observed that by increasing the concentration of dopants, the value of Ps and Pr were improved. According to the PL spectra, highly substituted materials had a low recombination rate and higher charge separation (e− - h+), which was ultimately accountable for higher photocatalytic activity. The dielectric loss decreases with frequency and dopant concentration. The photocatalytic activity of Dy 1-y La y Cr 1-x Co x O 3 was investigated against Crystal Violet (CV) dye under sunlight irradiation. The Dy 1-y La y Cr 1-x Co x O 3 furnished a 70% dye degradation in 90 min, which is attributed to the tunned bandgap and efficient electron-hole pair separation and the photocatalytic activity under visible light making Dy 1-y La y Cr 1-x Co x O 3 a promising photocatalyst for dye removal from wastewater. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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11. Ferroelectricity in empty tetragonal tungsten bronzes
- Author
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Gardner, Jonathan and Morrison, Finlay D.
- Subjects
546 ,Ferroelectric ,Dielectric ,Relaxor ,Structural disorder ,Powder neutron diffraction ,Powder X-ray diffraction ,Tetragonal tungsten bronze ,Structure-property ,QD181.W1G2 ,Ferroelectricity ,Tungsten bronze - Abstract
In this work, in-depth structural and electrical characterisation is used to study a family of “empty” tetragonal tungsten bronzes (TTBs), A2₄A1₂B1₂B2₈O₃₀. An initial investigation into the effect of the A1-cation size on the properties of empty Ba₄R₀.₆₇◻₁.₃₃Nb₁₀O₃₀ TTBs (where R is the A1-cation and R = La, Nd, Sm, Gd, Dy and Y; ◻ = vacancy) was performed. These were determined to be metrically tetragonal by powder x-ray diffraction, with decreasing R cation size inducing increased crystal anisotropy. This tetragonal structural distortion, driven by contraction in the ab-plane, is shown to stabilise c-axis ferroelectricity; a direct correlation between tetragonality and the ferroelectric Curie temperature, T[sub]C, is demonstrated. Further examination of the relaxor ferroelectric (RFE) to ferroelectric (FE) crossover in Ba₄(La₁₋ₓNdₓ)₀.₆₇◻₁.₃₃Nb₁₀O₃₀ TTBs using detailed structural studies employing variable temperature, high resolution neutron, synchrotron X-ray and electron diffraction revealed a common superstructure with 2√2 × √2 × 2 cell with respect to the basic tetragonal aristotype cell. However, they display different degrees of order/disorder which can disrupt polar order (ferroelectricity). La-rich analogues exhibit a disordered regime between the low and high temperature ferroelectric and non-polar phases. Although polar, this disordered regime is non-ferroelectric, however, large polarisation may be established with an applied electric field, but relaxes back to the disordered phase upon removal of the field. Substitution of Nd for La at the A1-site leads to destabilisation of the disordered phase and reintroduces “normal” ferroelectric behaviour. Finally, isovalent substitution of Sr²⁺∙ for Ba²⁺ is shown to lead to the development of relaxor behaviour at higher dopant concentrations in Ba₄₋ₓSrₓDy₀.₆₇◻₁.₃₃Nb₁₀O₃₀, (x = 0, 0.25, 0.5, 1, 2, 3; ◻ = vacancy). With increasing x the unit cell contracts in both the ab- plane and c-axis coinciding with a decrease in T[sub]C and development of relaxor behaviour for x ≥ 2. This observation is rationalised by differing cation occupancies: for x ≤ 1, Sr²⁺ principally occupies the A2-site while for x ≥ 2 significant Sr²⁺ occupation of the A1-site leads to the observed RFE characteristics. The FE to RFE crossover is discussed in the context of a previously proposed TTB crystal chemical framework with the A1-site tolerance factor identified as the dominant influence on relaxor behaviour.
- Published
- 2017
12. Effect of Nd and Mn Co-Doping on Dielectric, Ferroelectric and Photovoltaic Properties of BiFeO 3.
- Author
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Wu, Qiyuan, Song, Yanling, Jia, Caihong, Gao, Zhaomeng, and Zhang, Weifeng
- Subjects
FERROELECTRICITY ,PULSED laser deposition ,PHOTOVOLTAIC effect ,DIELECTRICS ,THIN films ,LEAD titanate - Abstract
Bi
1−x Ndx Fe0.99 Mn0.01 O3 (BNFMO, x = 0.00~0.20) films were epitaxially grown on Nb:SrTiO3 (001) substrates using pulsed laser deposition. It was found that the Nd-doping concentration has a great impact on the surface morphology, crystal structure, and electrical properties. BNFMO thin film with low Nd-doping concentration (≤16%) crystallizes into a rhombohedral structure, while the high Nd-doping (>16%) will lead to the formation of an orthogonal structure. Furthermore, to eliminate the resistive switching (RS) effect, a positive-up–negative-down (PUND) measurement was applied on two devices in series. The remnant polarization experiences an increase with the Nd-doping concentration increasing to 16%, then drops down with the further increased concentration of Nd. Finally, the ferroelectric photovoltaic effect is also regulated by the ferroelectric polarization, and the maximum photocurrent of 1758 μA/cm2 was obtained in Bi0.84 Nd0.16 Fe0.99 Mn0.01 O3 thin film. BNFMO films show great potential for ferroelectric and photovoltaic applications. [ABSTRACT FROM AUTHOR]- Published
- 2022
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- View/download PDF
13. Simultaneous normal – Anomalous dielectric dispersion and room temperature ferroelectricity in CBD perovskite BaTiO3 thin films
- Author
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Sidra Khan, Nudrat Humera, Saba Niaz, Saira Riaz, Shahid Atiq, and Shahzad Naseem
- Subjects
Barium titanate ,Chemical bath deposition ,Dielectric ,Optical ,Ferroelectricity ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Chemical bath deposition (CBD) method, being an electroless technique, is used to prepare phase pure barium titanate (BaTiO3) thin films using glass as substrate. Molarity of the solution is varied from 0.1 to 1.2 M, whereas, solution temperature is kept constant at 78 °C. XRD analyses show formation of perovskite tetragonal phase of BaTiO3 at all the molarities when films are annealed at 300 °C. Strengthening in perovskite tetragonal phase is observed with increase in solution molarity. Ellipsometric results show high transmission (∼ 83 %) in the visible region for thin films prepared with 1.2 M solution. Variation in direct band gap, 3.31–3.61 eV, is observed for annealed thin films. High dielectric constant (∼ 539.26 at log f = 3) and low tangent loss is obtained for 1.2 M based thin films. Thin films prepared under all the conditions show normal and anomalous / U-shaped frequency dependent dielectric response (i.e. ∼ 2754.24 at log f = 1.5 and ∼ 2004.73 at log f = 7.5). Maximum spontaneous polarization of ∼ 14.78 μC/cm2 and remnant polarization of ∼ 6.94 μC/cm2 are observed for 1.2 M sample. It is important to mention here that U-shaped high dielectric and good ferroelectric properties of BaTiO3 are observed in current study with no change in perovskite structure of tetragonal phase making it a potential candidate for storage devices at low and high frequencies.
- Published
- 2020
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14. Structural, dielectric, ferroelectric and electrical behavior of (Bi0.5Ba0.25Sr0.25)(Ti0.25Mn0.25Fe0.5)O3.
- Author
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Auromun, Krishna and Choudhary, R. N. P.
- Subjects
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DIELECTRICS , *SPACE charge , *DIFFRACTION patterns , *SPACE groups , *FERROELECTRICITY , *BARIUM titanate , *IRON-manganese alloys - Abstract
The Rietveld refined X-ray diffraction pattern of (Bi0.5Ba0.25Sr0.25)(Ti0.25Mn0.25Fe0.5)O3 sample synthesized through the high temperature mixed oxide solid state route confirms the tetragonal (space group: P4mm) symmetry. The scanning electron micrographs clearly explain the morphology of the sample. Temperature and frequency dependent dielectric parameters as well as the PE-hysteresis loop explain the validity of Curie Weiss law and ferroelectricity present in the material below the TC. The non-Debye type of relaxation, effect of grain and grain boundary on impedance is illuminated by the impedance analysis. The Field-leakage current (JE) characteristics revealed the space charge limited and Ohmic-type conduction process occurring in the material. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
15. Structural, dielectric, ferroelectric and electrical behavior of (Bi0.5Ba0.25Sr0.25)(Ti0.25Mn0.25Fe0.5)O3.
- Author
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Auromun, Krishna and Choudhary, R. N. P.
- Subjects
DIELECTRICS ,SPACE charge ,DIFFRACTION patterns ,SPACE groups ,FERROELECTRICITY ,BARIUM titanate ,IRON-manganese alloys - Abstract
The Rietveld refined X-ray diffraction pattern of (Bi
0.5 Ba0.25 Sr0.25 )(Ti0.25 Mn0.25 Fe0.5 )O3 sample synthesized through the high temperature mixed oxide solid state route confirms the tetragonal (space group: P4mm) symmetry. The scanning electron micrographs clearly explain the morphology of the sample. Temperature and frequency dependent dielectric parameters as well as the PE-hysteresis loop explain the validity of Curie Weiss law and ferroelectricity present in the material below the TC . The non-Debye type of relaxation, effect of grain and grain boundary on impedance is illuminated by the impedance analysis. The Field-leakage current (JE) characteristics revealed the space charge limited and Ohmic-type conduction process occurring in the material. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
16. A Flexible Energy Harvester from an Organic Ferroelectric Ammonium Salt.
- Author
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Gupta, Rishabh, Sahoo, Supriya, Deswal, Swati, Kothavade, Premkumar, Dixit, Prashant, Zaręba, Jan K., Shanmuganathan, Kadhiravan, and Boomishankar, Ramamoorthy
- Subjects
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MECHANICAL energy , *AMMONIUM salts , *HYSTERESIS loop , *ELECTRIC fields , *POWER density , *ENERGY harvesting , *TRIBOELECTRICITY - Abstract
Organic ferroelectrics due to their low cost, easy preparation, light weight, high flexibility and phase stability are gaining tremendous attention in the field of portable electronics. In this work, we report the synthesis, structure and ferroelectric behavior of a two‐component ammonium salt 2, containing a bulky [Bn(4‐BrBn)NMe2]+ (Bn=benzyl and 4‐BrBn=4‐bromobenzyl) cation and tetrahedral (BF4)− anion. The structural analysis revealed the presence of rich non‐classical C−H⋅⋅⋅F and C−H⋅⋅⋅Br interactions in this molecule that were quantified by Hirshfeld surface analysis. The polarization (P) vs. electric field (E) hysteresis loop measurements on 2 gave a remnant polarization (Pr) of 14.4 μC cm−2 at room temperature. Flexible polymer composites with various (5, 10, 15 and 20) weight percentages (wt%) of 2 in thermoplastic polyurethane (TPU) were prepared and tested for mechanical energy harvesting applications. A notable peak‐to‐peak output voltage of 20 V, maximum current density of 1.1 μA cm−2 and power density of 21.1 μW cm−2 were recorded for the 15 wt% 2‐TPU composite device. Furthermore, the voltage output generated from this device was utilized to rapidly charge a 100 μF capacitor, with stored energies and measured charges of 156 μJ and 121.6 μC, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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17. Influence of BaO Doping on the Structural, Ac Conductivity, and Dielectric Properties of BiFeO3 Multiferroic Nanoparticles.
- Author
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Salah, M., Morad, Ibrahim, Ali, H. Elhosiny, Mostafa, M. M., and El-Desoky, M. M.
- Subjects
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DIELECTRIC properties , *DOPING agents (Chemistry) , *CURIE temperature , *FERROELECTRICITY , *ELECTRIC conductivity , *NANOPARTICLES , *MULTIFERROIC materials , *LEAD-free ceramics - Abstract
The Bi1−xBaxFeO3 (BiBaFeO3) multiferroic nanoparticles with different Ba molar concentrations were fabricated in reliance on the solid-state reaction technique. Nanostructures of the prepared samples were confirmed by X-ray diffraction (XRD) together with Fourier transforms infrared (FTIR) spectroscopy, whereas the ac conductivity, dielectric and ferroelectric features were examined depending on the RLC Bridge, and Sawyer–Tower circuit. XRD patterns displayed the creation of rhombohedral–hexagonal single-phase of BiBaFeO3. The formation of BiBaFeO3 multiferroic nanoparticles was confirmed by FTIR spectra. Curie temperature (TC) was observed around 1121–1189 K. Ferroelectric polarization was enhanced with remnant polarization of 88.8 μC cm−2 by Ba2+ ions substitution at x = 0.15 mol%. Besides, ac electrical conductivities as a function of frequency as well as temperature were reported for all BiBaFeO3 multiferroic nanoparticles, which exhibit a strong frequency dependence with conduction mechanism is the correlated barrier hopping (CBH) model. The obtained high polarization and Curie temperature enhance their use in information storage devices. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
18. Structural, dielectric, ferroelectric and tuning properties of Pb-free ferroelectric Ba0.9Sr0.1Ti1-xSnxO3.
- Author
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Zaitouni, H., Hajji, L., Mezzane, D., Choukri, E., Gagou, Y., Hoummada, K., Charai, A., Alimoussa, A., Rožič, B., El Marssi, M., and Kutnjak, Z.
- Subjects
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DIELECTRICS , *FERROELECTRIC materials , *RIETVELD refinement , *FERROELECTRICITY , *FERROELECTRIC ceramics , *HYSTERESIS loop , *RAMAN spectroscopy - Abstract
A series of Pb-free ferroelectric materials Ba 0.9 Sr 0.1 Ti 1-x Sn x O 3 (BSTS-x) with 0 ≤ x ≤ 0.15 was successfully prepared via solid-state reaction method. The effect of Sn substitution on the crystal structure, microstructure, dielectric behavior, ferroelectric and tunable features of BSTS-x ceramics were systematically investigated. Room temperature (RT) x-ray diffraction (XRD) analysis using the Rietveld refinement method reveals that all the synthesized BSTS-x ceramics were well crystallized into single perovskite structure. The results show a tetragonal phase for 0.00 ≤ x ≤ 0.02, which evolves to orthorhombic and tetragonal coexisting phases for 0.05 ≤ x ≤ 0.07. The composition x = 0.10 showed a mixture of tetragonal, orthorhombic and rhombohedral phases at RT, while a single cubic phase is observed for x = 0.15. The crystal phases determined by XRD were confirmed by Raman spectroscopy. Enhanced dielectric permittivity with a maximum value of ε ' ~35000 is observed for x = 0.10 at RT. The ferroelectric behavior of BSTS-x ceramics was investigated through polarization hysteresis loops and tunability measurements. High tunability of 63% at RT and under the low DC-applied electric field of 1.40 kV/cm is achieved for x = 0.10. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
19. Unraveling potential phase transition mechanism of NBT-based systems: From an interesting view to survey ferroelectric loops.
- Author
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Wu, Xiaojun, Wu, Chao, Wen, Lanji, Yin, Jie, and Wu, Jiagang
- Subjects
- *
PHASE transitions , *DIELECTRIC loss , *STRAIN rate , *FERROELECTRIC ceramics , *EVALUATION methodology - Abstract
As for assessing strain performances of Na 0.5 Bi 0.5 TiO 3 -based systems, the driving field level is a critical parameter. Currently, both current density and strain rate evaluation methods have been utilized to characterize the driving field. However, we find that some discrepancies indeed exist between these two evaluation methods, especially for the highly ergodic condition. By means of the typical ferroelectric theory, the initial analysis for discrepant current density and strain rate loops reveals that the relaxor-ferroelectric transition is likely to be a multi-step transition process. Dynamic dielectric loss/permittivity evolution further confirms the speculation and suggests that partial transition steps may be consisted of successive transition events. Ferroelectric and dielectric loops not only provide a fantastic view to unravel the multi-step relaxor-ferroelectric transition process, but also guides to regulate the strain appraisal system. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. Structural, ferroelectric and photocatalytic performance of Ba1-xCaxTiO3 ceramics.
- Author
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Suresh, P., Mathiyalagan, P., and Srikanth, K. S.
- Subjects
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TRANSITION temperature , *PHASE transitions , *SPACE charge , *HYSTERESIS loop , *FERROELECTRIC ceramics , *PERMITTIVITY , *FERROELECTRICITY - Abstract
Ba1-xCaxTiO3 (Ca added BaTiO3; x = 0–0.3) ceramics is used as a target catalyst to probe the influence of ferro-electricity on the de-colorization of a typical dye molecule Methyl orange under visible light irradiation. The results indicated that there is a two fold increase in the de-colorization rate using Ba0.7Ca0.3TiO3 in around 180 min. This is ascribed to the ferro-electricity of the tetragonal phase. To probe the ferro-electricity in the catalyst, the P-E hysteresis loops show high polarization of 17.50 µC/cm2 in x = 0.3 compared to 10 µC/cm2 for x = 0 at 303 K. The high value of polarization in Ca added BaTiO3 enhances ferro-electricity and ensures a tightly bound layer of dye molecule and also acts to separate the photo-excited carriers due to the internal space charge layer. Both these features act to enhance the catalytic performance. Further, we studied the temperature dependence of dielectric study and it was found that dielectric constant increased and undergoes a maximum corresponding to a phase transition (330 K for x = 0.3) and thereafter decreased. The Ca substitution diffused the phase transition of BaTiO3 and resulted in shift of transition temperature towards room temperature with increase in content of Ca which is useful for many dielectric applications. [ABSTRACT FROM AUTHOR]
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- 2020
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21. Effect of PMN modification on the structural, microstructural, dielectric and ferroelectric properties of BT ceramics.
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Negi, R. R. and Kumar, P.
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DIELECTRIC properties , *CERAMICS , *PERMITTIVITY , *FERROELECTRICITY , *LOW temperatures , *GRAIN size , *DIELECTRIC loss - Abstract
(1-x)BT-xPMN (x = 0, 0.02, 0.04, 0.06, 0.08 and x = 1) ceramic samples were synthesized by solid state reaction route. XRD study confirmed the formation of single perovskite phase of the BT-PMN system. Increase in density with drastic decrease in average grain size was observed with the increase of PMN content. High value of room temperature dielectric constant (εr) with low value of dielectric loss (tanδ) at room temperature and at 10 kHz frequency was obtained in x = 0.06 ceramic samples, however low temperature coefficient of capacitance (from RT to 100 °C) was obtained in x = 0.08 ceramic samples. [ABSTRACT FROM AUTHOR]
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- 2020
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22. Structural, dielectric and magnetoelectric coupling analysis in SrBi2Nb2O9–CoFe2O4 composites.
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Chaudhary, Prachi, Dabas, Samiksha, Kumar, Manish, Kumar, Arvind, and Thakur, O P
- Abstract
Ferroelectric–magnetic composites of SrBi2Nb2O9–CoFe2O4 (SBN–CFO) were synthesized via conventional solid state reaction route. The powder X-ray diffraction, Raman spectroscopy and scanning electron microscopy measurements confirm the existence of two chemically separated phases and phase purity in the SBN–CFO composites. Magnetization measurements confirm the enhanced values of the magnetic parameters. The change in the area of the ferroelectric P vs. E loops with frequency confirms the enhanced ferroelectric nature of the SBN–CFO composites. The quantified maximum values of magnetoelectric coefficient (α) are observed from the P vs. E loop measurements in the influence of applied magnetic field and found to be 4.475 mV cm−1 Oe−1 at 688 Oe for SBN–0.1CFO and 3.389 mV cm−1 Oe−1 at 1000 Oe for SBN–0.2CFO composites, respectively. The shifting in the peaks of temperature-dependent dielectric maxima towards the higher temperature side confirms the relaxor behaviour in the SBN–CFO composite samples. [ABSTRACT FROM AUTHOR]
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- 2020
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23. Ultrabroad temperature stability of stuffed tridymite-type BaAl2O4 co-doped by [Zn0.5Ti0.5]3+ with weak ferroelectricity.
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Li, Jie, Lan, Xue-Kai, Du, Kang, Song, Xiao-Qiang, Lu, Wen-Zhong, Wang, Xiao-Hong, and Lei, Wen
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- *
FERROELECTRICITY , *DIELECTRIC properties , *FERROELECTRIC transitions , *CHEMICAL bond lengths , *ALUMINUM-zinc alloys , *SPACE groups , *CERAMIC capacitors - Abstract
The structure and dielectric properties of BaAl (2−2 x) (Zn 0.5 Ti 0.5) 2 x O 4 ceramics were investigated. Single-phase solid solutions in space group P6 3 (No. 173) were confirmed when 0% ≤ x ≤ 1.6%. [Zn 0.5 /Ti 0.5 ]3+ averagely occupied four symmetrically inequivalent Al sites, and Al1/(Zn,Ti)–O, Al2/(Zn,Ti)–O and Al3/(Zn,Ti)–O bond lengths increased with increased x. Two dielectric anomalous peaks existed, the first peak referred to second-order ferroelectric transition. Stability was significantly improved by moving the first dielectric abnormal peak from 123 °C to −22 °C due to the lower atomic shift amplitude Δz of B cations along the polar axis. The co-doping of Zn2+ and Ti4+ played a decisive role in realizing an ultrabroad temperature range (−100 °C–700 °C) of stability (−27 ppm/°C ≤ TCC ≤ +10 ppm/°C), which met the conditions of C0G or NP0 multilayer ceramic capacitors (±30 ppm/°C). Superior insulating properties were performed by high resistivity of > 1014 Ω cm. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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24. Investigations on structural and electrical characteristics of Fe and W modified BaTiO3 ceramic.
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Gupta, Prabhasini, Mahapatra, P.K., and Choudhary, R.N.P.
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ORTHORHOMBIC crystal system , *DIELECTRIC properties , *FERROELECTRIC transitions , *FERROELECTRICITY , *ACTIVATION energy , *RELAXOR ferroelectrics - Abstract
Ba(Fe 1/3 Ti 1/3 W 1/3)O 3 , was successfully prepared by the cost effective mixed oxide reaction method at 1000 °C. Analysis of X-ray diffraction (XRD) data indicates the crystallization of the compound in the orthorhombic crystal system. A dielectric anomaly observed at around 59 °C shifts to the higher temperature side with increase in frequency can be explained by Maxwell-Wagner polarization mechanism, whereas an another anomaly observed at 126 °C can be considered as the ferroelectric to paraelectric transition. The dielectric property was analyzed by modified Cole-Cole relation, and the impedance using Nyquist plot. The activation energy calculated from grain resistance and the relaxation parameters amounts to be 0.54 eV. Analysis of the conductivity curves using the Jonscher's power law suggests OLPT model and CBH model as the dominant conduction mechanism in the ferroelectric and paraelectric phase in the sample. The ferroelectricity of the sample was confirmed by the room temperature P ~ E loop. [ABSTRACT FROM AUTHOR]
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- 2019
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25. 核-壳结构界面对纳米Ag掺杂BaTiO3@PDA/ P(VDF-HFP)复合膜介电和储能性能影响.
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夏卫民, 张慧慧, and 顾玉娇
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ELECTRIC displacement ,ENERGY storage ,ENERGY density ,DIELECTRIC properties ,POLYVINYLIDENE fluoride ,FERROELECTRICITY ,DIELECTRIC loss - Abstract
Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2019
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26. Influence of diamagnetic Zn on structural, ferroelectric and ferromagnetic properties of BiFe1-xZnxO3 (0% ≤ x ≤ 8%).
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Mani, Angom Devadatta and Soibam, Ibetombi
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MULTIFERROIC materials , *SOL-gel processes , *MICROSTRUCTURE , *DIELECTRIC properties - Abstract
Abstract Nanocrystallites with the compositional formula BiFe 1-x Zn x O 3 (x = 0.0, 0.01, 0.03, 0.05, 0.08) were synthesised by sol-gel method route. The influence of Zn doping on structural, dielectric, ferroelectric and ferromagnetic properties was discussed in detail. XRD studies confirmed the crystallinity and phase formation of all the samples. Slight lattice distortion has been observed for x = 0.08 sample as compared to the pure phase BiFeO 3 (BFO). Microstructural investigations using SEM showed the increase in grain size with the increase in Zn addition. FTIR studies reveal the presence of necessary bonds in the samples. Enhanced dielectric and ferroelectric properties have been observed with Zn doping upto x = 0.05 concentration and then decreases. Room temperature MH loop showed enhanced ferromagnetic properties upto x = 0.03 Zn content and decreases thereafter. Explanation of the above results was discussed extensively. Simultaneous improvement in both ferroelectric and ferromagnetic properties might bring considerable interest in various multiferroic applications. Highlights • BiFe1-xZnxO3 (x = 0.0, 0.01, 0.03, 0.05, 0.08) nanocrystallites were successfully prepared by low temperature sol-gel method. • Dielectric response shows dispersive behaviour with the frequency of the applied electric field. • Enhanced dielectric and ferroelectric properties has been observed with Zn addition upto x = 0.05 concentration. • Improved ferromagnetic properties has also been observed upto x = 0.03 Zn content. • Studies on magneto-electric coupling were underway for the practical realisation of Zn doped BFO in various multiferroic applications. [ABSTRACT FROM AUTHOR]
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- 2019
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27. Influence of Al doping on structural, dielectric, and ferroelectric properties of multiferroic BiFeO3 ceramics.
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Bai, Peijia, Zeng, Yiming, Han, Jiao, Wei, Yongxing, and Li, Mingwei
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ALUMINUM , *DOPING agents (Chemistry) , *FERROELECTRICITY , *MULTIFERROIC materials , *CRYSTAL structure - Abstract
Abstract Lead-free BiFe 1- x Al x O 3 ceramics with x = 0, 0.005, 0.01, 0.015, and 0.02 were synthesised via the traditional solid-state reaction method. The effects of Al doping on the crystalline structure, dielectric, and ferroelectric properties were investigated. X-ray diffraction results indicated that Al doping increased the secondary phases (Bi 2 Fe 4 O 9 and Bi 25 FeO 39) when the Al content was above 0.015. Scanning electron microscopy images showed that the grain size in the BiFe 1- x Al x O 3 ceramics decreased from 1.6 to 0.45 µm with the increase of the Al content. Samples with a small amount of Al doping exhibited improvements in the remnant polarisation and dielectric constant compared with pure BiFeO 3. However, when the Al content increased, the dielectric constant decreased and the polarisation hysteresis loops become unsaturated. With the increase of the Al content, the T C increased and exceeded 500 °C, and the leakage current densities of the BiFe 1- x Al x O 3 ceramics first increased and then decreased. These changes of the electric properties were related to the decrease of the grains size, the generation of secondary phases, and the increase of carriers. [ABSTRACT FROM AUTHOR]
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- 2019
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28. Effect of Co2+ substitution in B-sites of the perovskite system on the phase formation, microstructure, electrical and magnetic properties of Bi0.5(Na0.68K0.22Li0.10)0.5TiO3 ceramics
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Supree Pinitsoontorn, Chonnarong Kaewsai, Tawat Suriwong, Pamornnarumol Bhupaijit, Theerachai Bongkarn, Surirat Yotthuan, and Naratip Vittayakorn
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Materials science ,Strain (chemistry) ,Mechanical Engineering ,Substitution (logic) ,Metals and Alloys ,Dielectric ,Microstructure ,Ferroelectricity ,Phase formation ,Crystallography ,Geochemistry and Petrology ,Mechanics of Materials ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Ceramic ,Perovskite (structure) - Published
- 2022
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29. Relaxor behavior and superior ferroelectricity of Y2O3-doped (Ba0.98Ca0.02) (Ti0.94Sn0.04Zr0.02)O3 lead-free ceramics
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Enpei Cai, An Xue, Sifan Wang, Fanghui Mou, and Qibin Liu
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Materials science ,Scanning electron microscope ,Doping ,Sintering ,02 engineering and technology ,General Chemistry ,Dielectric ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Piezoelectricity ,Ferroelectricity ,0104 chemical sciences ,Geochemistry and Petrology ,visual_art ,visual_art.visual_art_medium ,Ceramic ,Composite material ,0210 nano-technology - Abstract
To upgrade the electric properties of lead-free piezoceramics, (1–x)(Ba0.98Ca0.02Ti0.94Sn0.04Zr0.02)O3-xY2O3 (abbreviated as (1–x)BCTSZ-xY, x = 0 mol%, 0.02 mol%, 0.04 mol%, 0.06 mol%, 0.08 mol% and 0.1 mol%) ceramics were successfully synthesized by traditional solid-state sintering method. The phase structure and microstructure of ceramics were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and piezoresponse force microscopyeramics (PFM). The electric properties of ceramics were researched through piezoelectric, dielectric and ferroelectric test instruments. The results show that all samples have pure perovskite structure and favorable electric properties. The optimal electric properties which especially include superior ferroelectric properties are gained when Y2O3 content is 0.06 mol% (d33 = 419 pC/N, kp = 52%, Tc = 89.5 °C, er = 26900, tanδ = 2.86%, Pr = 14.41 μC/cm2, Ec = 1.8 kV/cm). Moreover, the temperature-dependent dielectricity of samples shows apparent relaxor behavior under different frequencies. The Curie–Weiss law further proves that all samples are typical relaxor ferroelectrics, and the relaxor degree of samples decreases with increase of Y2O3 content. In conclusion, Y2O3 plays a significant role in enhancing electric properties of BCTSZ ceramics.
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- 2022
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30. Ferroelectricity in dopant-free HfO2 thin films prepared by pulsed laser deposition
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Jiyan Dai, Xubing Lu, Xingsen Gao, Yongjian Luo, Min Zeng, Minghui Qin, Deyang Chen, Chao Chen, Jun-Ming Liu, Guofu Zhou, Zhen Fan, Xiaozhe Yin, and Zhenxun Tang
- Subjects
Materials science ,Dopant ,Ferroelectricity ,Annealing (metallurgy) ,business.industry ,Metals and Alloys ,Pulsed laser deposition ,Dielectric ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,TA401-492 ,Optoelectronics ,Deposition (phase transition) ,Thin film ,business ,Layer (electronics) ,Materials of engineering and construction. Mechanics of materials ,Orthorhombic phase ,Hafnium oxide - Abstract
As a high-k material, hafnium oxide (HfO2) has been used in gate dielectrics for decades. Since the discovery of polar phase in Si-doped HfO2 films, chemical doping has been widely demonstrated as an effective approach to stabilize the ferroelectric phase in HfO2 based thin films. However, the extra capping layer deposition, post-growth annealing and wake-up effect are usually required to arouse the ferroelectricity in HfO2 based thin films, resulting in the increase of complexity for sample synthesis and the impediment of device application. In this study, the ferroelectricity is observed in non-capped dopant-free HfO2 thin films prepared by pulsed laser deposition (PLD) without post-growth annealing. By adjusting the deposited temperature, oxygen pressure and thickness, the maximum polarization up to 14.7 μC/cm2 was obtained in 7.4 nm-thick film. The fraction of orthorhombic phase, concentrations of defects and size effects are considered as possible mechanisms for the influences of ferroelectric properties. This study indicates that PLD is an effective technique to fabricate high-quality ferroelectric HfO2 thin films in the absence of chemical doping, capping layer deposition and post-growth annealing, which may boost the process of nonvolatile memory device application.
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- 2022
31. Phase evolution and relaxor to ferroelectric phase transition boosting ultrahigh electrostrains in (1−x)(Bi1/2Na1/2)TiO3-x(Bi1/2K1/2)TiO3 solid solutions
- Author
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Denis Alikin, Lin Zhang, Qingyuan Hu, Leiyang Zhang, Li Jin, Gang Liu, V. Ya. Shur, Xiaoyong Wei, Haibo Zhang, and Ruiyi Jing
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Diffraction ,Phase transition ,Materials science ,Condensed matter physics ,Relaxor ferroelectric ,BKT ,Metals and Alloys ,Phase evolution ,ELECTROSTRAIN ,Dielectric ,Electrostrain ,PHASE DIAGRAM ,Polarization (waves) ,Ferroelectricity ,Phase diagram ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,RELAXOR FERROELECTRIC ,Electric field ,TA401-492 ,PHASE EVOLUTION ,Binary system ,BNT ,Materials of engineering and construction. Mechanics of materials ,Solid solution - Abstract
Owing to the complex composition architecture of these solid solutions, some fundamental issues of the classical (1−x)Bi1/2Na1/2TiO-xBi1/2K1/2TiO3 (BNT-xBKT) binary system, such as details of phase evolution and optimal Na/K ratio associated with the highest strain responses, remain unresolved. In this work, we systematically investigated the phase evolution of the BNT-xBKT binary solid solution with x ranging from 0.12 to 0.24 using not only routine X-ray diffraction and weak-signal dielectric characterization, but also temperature-dependent polarization versus electric field (P-E) and current versus electric field (I-E) curves. Our results indicate an optimal Na/K ratio of 81/19 based on high-field polarization and electrostrain characterizations. As the temperature increased above 100 °C, the x = 0.19 composition produces ultrahigh electrostrains (> 0.5%) with high thermal stability. The ultrahigh and stable electrostrains were primarily due to the combined effect of electric-field-induced relaxor-to-ferroelectric phase transition and ferroelectric-to-relaxor diffuse phase transition during heating. More specifically, we revealed the relationship between phase evolution and electrostrain responses based on the characteristic temperatures determined by both weak-field dielectric and high-field ferroelectric/electromechanical property characterizations. This work not only clarifies the phase evolution in BNT-xBKT binary solid solution, but also paves the way for future strain enhancement through doping strategies. © 2021 The Chinese Ceramic Society. This work was supported by the National Natural Science Foundation of China (Grant Nos. 51772239 and 51761145024 ) and the Fundamental Research Funds for the Central Universities ( XJTU ). The SEM work was done at International Center for Dielectric Research (ICDR), Xi'an Jiaotong University, Xi'an, China.
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- 2022
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32. Effect of (Zn, Mn) co-doping on the structure and ferroelectric properties of BiFeO3 thin films
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Chang-Chang Zhang, Xia-Li Liang, and Jian-Qing Dai
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Materials science ,Scanning electron microscope ,Band gap ,Process Chemistry and Technology ,Doping ,Analytical chemistry ,Dielectric ,Ferroelectricity ,Grain size ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Materials Chemistry ,Ceramics and Composites ,Thin film ,Polarization (electrochemistry) - Abstract
BiFe1-2xZnxMnxO3 (BFZMO, with x = 0–0.05) thin films were synthesized via sol–gel method. Effects of (Zn, Mn) co-doping on the structure, ferroelectric, dielectric, and optical properties of BiFeO3 (BFO) films were investigated. BFZMO thin films exhibit rhombohedral structure. Scanning electron microscopy (SEM) images indicate that co-doping leads to a decrease in grain size and number of defects. Leakage current density (4.60×10−6 A/cm2) of BFZMO film with x = 0.02 was found to be two orders of magnitude lower than that of pristine BFO film. Owing to decreased leakage current density, saturated P–E curves were obtained. Maximum double remnant polarization of 413.2 μC/cm2 was observed for BFZMO thin film with x = 0.02, while that for the BFO film was found to be 199.68 μC/cm2. The reason for improved ferroelectric properties is partial substitution of Fe ions with Zn and Mn ions, which resulted in a reduction in the effect of oxygen vacancy defects. In addition, co-doping was found to decrease optical bandgap of BFO film, opening several possible routes for novel applications of these (Zn, Mn) co-doped BFO thin films.
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- 2022
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33. Enhanced energy-storage performance in a flexible film capacitor with coexistence of ferroelectric and polymorphic antiferroelectric domains
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Xiaobo Yu, Yuxuan Hou, Peng Chen, Pingping Liu, Xiaokuo Er, Jiesen Guo, Qian Zhan, and Yang Bai
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Materials science ,Energy storage ,business.industry ,Flexible dielectric capacitor ,Bending endurance ,Metals and Alloys ,Dielectric ,Thermal stability ,Ferroelectricity ,Flexible electronics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,Capacitor ,Film capacitor ,law ,TA401-492 ,Optoelectronics ,Thin film ,business ,Materials of engineering and construction. Mechanics of materials - Abstract
Advances in flexible electronics are driving dielectric capacitors with high energy storage density toward flexibility and miniaturization. In the present work, an all-inorganic thin film dielectric capacitor with the coexistence of ferroelectric (FE) and antiferroelectric (AFE) phases based on Pb0.96La0.04(Zr0.95Ti0.05)O3 (PLZT) was prepared on a 2D fluorophlogopite mica substrate via a simple one-step process. The flexible capacitor exhibits a high recoverable energy density (Urec) of ≈ 44.2 J/cm3, a large electric breakdown strength (EBDS) of 3011 kV/cm, excellent frequency stability (500 Hz-20 kHz) and high thermal stability over 30–190 °C. It also demonstrates an outstanding bending endurance, which can maintain a high energy storage performance under various bending radii (R = 2–10 mm) or 103 repeated bends at 4 mm. The FE phase is stable near the film surface and the interface with the bottom electrode. The AFE phase with multi-domains has incommensurate modulation structures with super-periodicity of 6.5, 6.9 and 5.2. It indicates that the PLZT/LNO/F-Mica capacitor has high potential for energy storage application and may provide great opportunities for exploring new energy storage materials.
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- 2022
34. Enhanced energy storage performance of eco-friendly BNT-based relaxor ferroelectric ceramics via polarization mismatch-reestablishment and viscous polymer process
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Ruiyi Jing, Jinghui Gao, Denis Alikin, Qingyuan Hu, Yule Yang, Wenjing Shi, Leiyang Zhang, Li Jin, V. Ya. Shur, and Xiaoyong Wei
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Materials science ,Process Chemistry and Technology ,Dielectric ,Atmospheric temperature range ,Ferroelectricity ,Energy storage ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Thermal stability ,Ceramic ,Composite material ,Polarization (electrochemistry) ,Porosity - Abstract
In this work, we synthesized a novel and eco-friendly relaxor ferroelectric system, i.e., (1−x)(0.8Bi0.5Na0.4K0.1TiO3-0.2SrTiO3)-xNaNbO3 (BS-xNN) ceramics with x = 0.1–0.4 based on a solid state reaction technique. The structural, microstructural, dielectric as well as ferroelectric characteristics of BS-xNN ceramics were comprehensively examined. According to our findings, the Ti–O coupling reduces as the NN content increases, while the Nb–O coupling strengthens, leading in a nano-scale polarization mismatch-reestablishment process that enhances energy storage performance. Because of the reduction in thickness and porosity, the viscous polymer process significantly increases the breakdown strength of ceramic samples. More crucially, at 260 kV/cm, 0.6BS-0.4NN ceramics have an ultrahigh recoverable energy storage density Wrec of 4.44 J/cm3 and a high energy storage efficiency η of 81.8%. Furthermore, thermal stability of energy storage performance is also identified across a wide temperature range of 30 °C from 140 °C at 215 kV/cm. The higher performance of energy storage not only indicates the feasibility of our technique, but also serves as a model for the manufacturing of high-quality dielectric ceramics with a wide range of industrial applications.
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- 2022
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35. Enhanced piezoelectric properties of Sm3+-modified PMN-PT ceramics and their application in energy harvesting
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Fengji Zheng, Yalin Qin, Ze Fang, Xiao-Xiong Wang, Wanneng Ye, Xue Tian, Xiaodong Jiang, and Yongcheng Zhang
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Electromechanical coupling coefficient ,Materials science ,Process Chemistry and Technology ,Dielectric ,Microstructure ,Ferroelectricity ,Piezoelectricity ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Energy transformation ,Ceramic ,Composite material ,Energy harvesting - Abstract
Piezoelectric materials are widely used in electromechanical energy conversion, such as in sensors, transducers, and self-powered materials. In this paper, the influence of the Sm doping content on the microstructure and ferroelectric, piezoelectric, dielectric, and field-induced strain properties of 0.70Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 (PMN-PT) ceramics was investigated. Sm-doped PMN-PT ceramics with both high piezoelectric properties (d33∼1406 pC/N) and a large electromechanical coupling coefficient (kp∼0.69) were synthesized. Based on their piezoelectric effect, a maximum output voltage of 31 V was achieved under external forces. The output voltages showed satisfactory stability, repeatability, and sensitivity under periodic external forces; hence, Sm-doped PMN-PT piezoelectric ceramics are potential candidates for energy conversion and signal monitoring.
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- 2022
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36. Local structure engineered lead-free ferroic dielectrics for superior energy-storage capacitors: A review
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Ruzhong Zuo, He Qi, and Aiwen Xie
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Materials science ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,Dielectric ,Pulsed power ,Ferroelectricity ,Engineering physics ,Energy storage ,law.invention ,Condensed Matter::Materials Science ,Dipole ,Capacitor ,law ,Electric field ,General Materials Science ,Perovskite (structure) - Abstract
With the development of energy-storage technology and power electronics industry, dielectric capacitors with high energy density are in high demand owing to their high power density. Especially for ferroic dielectrics (including ferroelectrics and antiferroelectrics) showing dipole moments in the perovskite unit cells, large dielectric response under electric fields makes them own outstanding potentials for achieving high energy-storage density. Particularly, destroying long-range ferroelectric/antiferroelectric ordering by enhancing compositional disorder is found to be effective for extremely improving energy-storage properties (both high recoverable energy-storage density and efficiency), because these macroscopic-nonpolar nanodomains are highly polarizable under strong external electric fields. Moreover, owing to the heterogeneous structure induced dielectric relaxation characteristics, excellent temperature stability can be achieved simultaneously. The recent developments of (anti)polar nanoregions with different possible local symmetries in various lead-free perovskite-structured dielectrics have been summarized in this review, together with the achieved energy-storage properties based on them. This review would provide a guidance for preparing high-performance energy-storage capacitors by local-structure engineering for next-generation pulse power applications.
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- 2022
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37. The electrochemical, dielectric, and ferroelectric properties of Gd and Fe doped LaNiO3 with an efficient solar-light driven catalytic activity to oxidize malachite green dye
- Author
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Shagufta Kamal, Hind Albalawi, Farzana Majid, Sadia Ata, Kashif Jilani, Ismat Bibi, Nosheen Nazar, Munawar Iqbal, Shahid Iqbal, and Norah Alwadai
- Subjects
Materials science ,Dopant ,Doping ,Dielectric ,Conductivity ,Coercivity ,Ferroelectricity ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Biomaterials ,Colloid and Surface Chemistry ,Chemical engineering ,Photocatalysis ,Fourier transform infrared spectroscopy - Abstract
This work investigates the effects of double ion substitution on the ferroelectric, electrochemical, dielectric and photocatalytic properties of Gd and Fe doped La1-yGdyNi1-xFexO3 nanoparticles (NPs). La1-yGdyNi1-xFexO3 was fabricated by facile micro-emulsion path and its properties were studied by thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman scattering, Fourier Transform of Infrared (FTIR), energy dispersive x-rays (EDX) techniques. It has a distorted rhombohedral shape with crystallite size within the range of 17–23 nm. The doped material has a spherical heterogeneous morphology, and its surface area increased with increased doping. The electrochemical (CV, EIS, and I-V), conductivity and dielectric (dielectric constant and low dielectric & tangent loss) properties of La1-yGdyNi1-xFexO3 were dependent on the contents of the dopants (Gd and Fe). The doped material had improved specific capacitance compared to the undoped LaNiO3 due to the synergistic effect of Gd and Fe on the doped materials. The conductivity of Gd and Fe doped LaNiO3 5.16 × 104 Sm−1 was enhanced compared to the undoped LaNiO3 3.52 × 10−2 Sm1. Furthermore, hysteresis loop was used to investigate the coercivity (Hc), saturation magnetization (Ms) and remanence (Mr) of the material. The Ms and Mr values were enhanced with the content of the dopants. The photocatalytic activity (PCA) of the material in degrading malachite green (MG) dye was studied. La1-yGdyNi1-xFexO3 NPs was able to degrade up to 96.4% of the dye under visible light irradiation in 50 min. La1-yGdyNi1-xFexO3 has remarkable dielectric, electrochemical, ferroelectric and photo-catalytic properties and have potential applications in microwave, electrical, electronic, energy storage devices. It is also an active photo-catalyst material for the removal/oxidation of toxic pollutants from the environment.
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- 2022
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38. Charge compensation mechanisms of BaTiO3 ceramics co-doped with La2O3 and Bi2O3
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Jia Liu, Huiling Du, Xian Du, Cuiying Ma, and Danni Feng
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Materials science ,Dopant ,Process Chemistry and Technology ,Doping ,Analytical chemistry ,Ionic bonding ,Dielectric ,Ferroelectricity ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,symbols.namesake ,Phase (matter) ,visual_art ,Materials Chemistry ,Ceramics and Composites ,symbols ,visual_art.visual_art_medium ,Ceramic ,Raman spectroscopy - Abstract
Doping modification is commonly used to improve the electrical properties of BaTiO3 (BT). In this study, the ((1-x)BT-x(Bi2O3–La2O3)) ceramics were synthesised to investigate the charge balance compensation mechanisms of BT ceramics co-doped with La2O3 and Bi2O3 as donors at A-site. The XRD results showed that a pseudo-cubic phase was formed by intruding dopants. The Raman spectroscopy revealed that the samples, which x = 0.10 and 0.16, had relatively more oxygen and titanium vacancies. After heat-treatment the samples in oxygen atmosphere, the dielectric constant of the sample with x = 0.10 was higher than that of the untreated, but for x = 0.16, it was almost no changed. These results indicated that the different charge balance compensation mechanism was exist in the samples with x = 0.10 and 0.16. Impedance measurements showed that the resistance tendency exhibited initial decrease and subsequent increase, leading to the electronic and ionic compensation mechanisms with x = 0.10 and 0.16, respectively. Ferroelectric properties also implied charge balance compensation mechanism transition, due to Ps and Pr were higher for x = 0.10 than for x = 0.16, respectively. This work provides a new strategy for modulating the electric properties of BT-based ceramics.
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- 2022
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39. Microstructure and ferroelectric properties of Ta-doped Bi3.25La0.75Ti3O12/ZnO thin film capacitors
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Shuai Ma, Zhijun Xu, Min Wang, Wei Li, Shiqiang Ren, and Jigong Hao
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Materials science ,business.industry ,Process Chemistry and Technology ,Doping ,Dielectric ,Sputter deposition ,Microstructure ,Ferroelectricity ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Sputtering ,Materials Chemistry ,Ceramics and Composites ,Optoelectronics ,Lamellar structure ,Thin film ,business - Abstract
Ta-doped Bi3.25La0.75Ti3O12(BLTT)/ZnO films were fabricated on Pt(111)/Ti/SiO2/Si substrates by a magnetron sputtering method. Firstly, ZnO crystal thin films were grown on the substrates by a reactive sputtering method. Then, BLTT thin films were deposited on the ZnO layers at room temperature and post-annealed at 600 °C. The micromorphology, ferroelectric and dielectric properties of BLTT/ZnO films were analyzed. The XRD analysis shows that ZnO buffer layer significantly reduces the crystallization temperature of BLTT thin film. The TEM results show that lamellar BLTT grains are grown on ZnO layer at a certain angle with few elements diffusion at the interface of ZnO phase and Bi4Ti3O12 phase. The ferroelectric properties indicate that BLTT/ZnO films exhibit different remanent polarization and coercive fields under electric field with different directions. The novel mechanism of tailoring ferroelectric properties may open new possibilities for designing special ferroelectric devices.
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- 2022
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40. Polymer‐/Ceramic‐based Dielectric Composites for Energy Storage and Conversion
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Bo Li, He Huang, Hong-Hui Wu, Huimin Qiao, Fangping Zhuo, Qiaobao Zhang, Xinping Mao, Shuize Wang, Mupeng Zheng, and Lalitha Kodumudi Venkataraman
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chemistry.chemical_classification ,Materials science ,Renewable Energy, Sustainability and the Environment ,Composite number ,Polymer ,Dielectric ,Environmental Science (miscellaneous) ,Ferroelectricity ,Energy storage ,chemistry ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,Ceramic ,Composite material ,Waste Management and Disposal ,Energy (miscellaneous) ,Water Science and Technology - Published
- 2022
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41. Stability of rhombohedral structure and improved dielectric and ferroelectric properties of Ba, Na, Ti doped BiFeO3 solid solutions
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Subhash Sharma, Jesús M. Siqueiros, Oscar Raymond Herrera, and Hilal Ahmad Reshi
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Materials science ,Rietveld refinement ,Process Chemistry and Technology ,Analytical chemistry ,Crystal structure ,Dielectric ,Ferroelectricity ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Grain growth ,symbols.namesake ,X-ray photoelectron spectroscopy ,Materials Chemistry ,Ceramics and Composites ,symbols ,Raman spectroscopy ,Solid solution - Abstract
A study of the (1-x)BiFeO3-(x)Ba1/2Na1/2TiO2.75 (BFO-BNT) solid solutions obtained using the solid state reaction method, for different molar relative concentration of Ba1/2Na1/2TiO2.75 in the 0.0 ≤ x ≤ 0.12 composition range, is presented. The crystal structure and the dielectric and ferroelectric properties are studied in detail. Results of the Rietveld refinement of the X-ray diffraction data demonstrate that the system is single phase with R3c symmetry up to x = 0.09 while for x = 0.12, a small quantity of a secondary phase with P4mm symmetry appears. Scanning electron microscopy demonstrates that BNT presence promotes grain growth resulting in larger grains. Raman spectroscopy shows that, with increasing x, some of the A and E Raman modes slightly reduce their intensity while shifting in frequency, evincing the structural changes caused by the Ba, Na, and Ti incorporation on the BFO lattice. The X-ray photoelectron spectroscopy study confirms the successful substitution and gradual structural distortion in the samples. The improvement in dielectric properties with increasing BNT concentration can be attributed to stable dipole moment formation. Compared with pure BFO ceramics, doped BFO samples exhibit remarkably enhanced ferroelectric properties.
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- 2022
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42. High energy-storage performance of lead-free Ba0.4Sr0.6TiO3–Sr0.7Bi0.2TiO3 relaxor-ferroelectric ceramics with ultrafine grain size
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Tongtong Wang, Kun Guo, Zhiyong Liu, Jinshan Lu, Ling Zhang, Bing Xie, and Qi Wang
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Materials science ,Process Chemistry and Technology ,Dielectric ,Atmospheric temperature range ,Ferroelectricity ,Grain size ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Electric field ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Polar ,Ceramic ,Composite material ,Polarization (electrochemistry) - Abstract
Relaxor-ferroelectric (RFE) ceramics possess slender ferroelectric hysteresis loop and low remnant polarization (Pr). They have great potential to provide excellent energy-storage performance as dielectric energy-storage materials. Herein, a lead-free 0.8Ba0.4Sr0.6TiO3–0.2Sr0.7Bi0.2TiO3 (0.8BST–0.2SBT) RFE ceramic with high energy-storage performance has been realized successfully. The addition of Bi3+ and increase in Sr2+content at the A site of the BST can effectively inhibit the growth of grains for high breakdown strength (Eb). As a result, an ultrafine average grain size of 0.7 μm was obtained in 0.8BST–0.2SBT RFE ceramic, affording a high Eb of 300 kV/cm. Further investigation revealed that the mutual conversion of short-range polar nanoregions and long-range-ordered ferroelectric domains upon application and withdrawal of a 300 kV/cm applied electric field resulted in a high maximum polarization (Pmax) of 31 μC/cm2 and a low Pr of 2.5 μC/cm2. Hence, the 0.8BST–0.2SBT RFE ceramic simultaneously exhibited a high recoverable energy-storage density of 3.3 J/cm3 and a high energy-storage efficiency of 85% at 300 kV/cm. Additionally, a good energy-storage performance was reported over a temperature range of 50°C-120 °C and frequency from 10 to 1000 Hz, making the 0.8BST-0.2SBT RFE ceramic a potential lead-free dielectric energy-storage material.
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- 2022
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43. Structural, dielectric, ferroelectric and electrical properties of lead-free Ba0.9Sr0.1Ti0.9Sn0.1O3 ceramic prepared by sol–gel method
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A. Erramli, Yaovi Gagou, S. Khardazi, H. Zaitouni, S. Terenchuk, Daoud Mezzane, M'barek Amjoud, B. Asbani, and E. Choukri
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Materials science ,Analytical chemistry ,Dielectric ,Atmospheric temperature range ,Ferroelectricity ,Dielectric spectroscopy ,symbols.namesake ,Tetragonal crystal system ,visual_art ,symbols ,visual_art.visual_art_medium ,Grain boundary ,Ceramic ,Raman spectroscopy - Abstract
Lead-free Ba0.9Sr0.1Ti0.9Sn0.1O3 (BSTSn) ceramic was prepared by the sol–gel method. X-ray diffraction measurement at room temperature reveals the single-phase formation with tetragonal structure refined in the P4mm space group. Raman spectroscopy analysis at room temperature was used to confirm the structure of BSTSn ceramic sintered at 1420 °C during 5 h. The dielectric measurements were examined in the temperature range [−90 – 250 °C] and the frequency range of [100 Hz – 1 MHz]. The maximum dielectric constant was found to be ∼ 5484 (1 kHz) at room temperature. The diffuse phase transition characteristic at 1 kHz was ascribed by the modified Curie-Weiss law. Macroscopic polarization – field (P – E) hysteresis loops recorded at room temperature (RT) confirm the ferroelectric nature of BSTSn ceramic. Impedance spectroscopy analysis of BSTSn sample in the temperature range 300–380 °C reveals the presence of two relaxation contributions originated from grains and grain boundaries. Activation energies of grain and grain boundaries resistances were deduced in order to determine the conduction mechanism of the studied sample.
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- 2022
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44. Tunable dielectric and energy storage studies in NdMnO3 based composites
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S. Shankar, M. Jayasimhadri, and O. P. Thakur
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010302 applied physics ,Materials science ,Relaxation (NMR) ,Charge density ,02 engineering and technology ,Dielectric ,021001 nanoscience & nanotechnology ,Polarization (waves) ,Manganite ,01 natural sciences ,Ferroelectricity ,Energy storage ,Magnetic field ,Condensed Matter::Materials Science ,0103 physical sciences ,Composite material ,0210 nano-technology - Abstract
Composites are a class of materials which provide a scope of tailoring properties that are not possible amongst its constituents. Magnetoelectric composite materials exhibit product property arising because of mutually connected electric and magnetic phases. The systematic and comprehensive study on structural, tunable dielectric and flexible energy storage study of NdMnO3 (ND) manganite-based composites has been reported. The phase purity is estimated X-ray diffraction studies and confirm composite formation. The dielectric studies display a step-like decrease and reveal Maxwell-Wagner polarization with relaxation processes. The effect of magnetic field on dielectric constant reveals strong variation due to modification of spatial charge distribution. The qualitative evidence of tunable energy storage studies in ND based composites is observed by measuring the ferroelectric P-E hysteresis loop in variable magnetic field and is strain originated from coupling amongst individual component phases.
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- 2022
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45. Cold sintering of the ceramic potassium sodium niobate, (K0.5Na0.5)NbO3, and influences on piezoelectric properties
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Kosuke Tsuji, Sun Hwi Bang, Zhongming Fan, Sinan Dursun, Clive A. Randall, and Susan Trolier-McKinstry
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Permittivity ,Materials science ,Sintering ,Dielectric ,Ferroelectricity ,Hysteresis ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Grain boundary diffusion coefficient ,Grain boundary ,Ceramic ,Composite material - Abstract
Cold Sintering was applied to densify a Potassium-Sodium Niobate solid solution composition, 0.5KNbO3-0.5NaNbO3 (KNN); the process uses a transient chemical sintering aid, moderate pressure (400 MPa), and temperatures between 230–300 °C to obtain ceramics of ∼92 to 96 % theoretical density. Typically, sintering temperatures between ∼1000−1050 °C are required to density KNN using conventional methods. In this paper, the densification was investigated during heating, particularly the shrinkage in the first 60 min of the cold sintering process. The low-field dielectric and electrical properties of the resulting ceramics were found to be comparable to conventionally sintered KNN. Electric fields up to 80 kV/cm could be applied, however the ceramics showed pinched hysteresis loops, even after poling over a wide range of temperatures and electric fields. A Rayleigh analysis was used to investigate domain dynamics and high reversible permittivity. The irreversible behavior was an order of magnitude lower than in conventionally sintered KNN, likely associated with defect pinning of ferroelectric domains. A Transmission Electron Microscopy (TEM) study revealed a high density of line defects in most grains; dislocations in the grains limit poling and domain wall movement, thus suppressing both the piezoelectric properties and the hysteresis. Furthermore, TEM observations indicated crystalline grain boundaries that were faceted with terrace kink ledges. These observations point to the importance of the initial powder optimization and grain boundary diffusion when using cold sintering to prepare ceramics that are intended to show bulk cooperative properties such as ferroelectricity. The impact of limited high temperature homogenization of bulk diffusional processes is discussed.
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- 2022
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46. Enhanced energy-storage density and temperature stability of Pb0.89La0.06Sr0.05(Zr0.95Ti0.05)O3 anti-ferroelectric thin film capacitor
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Ju Gao, Zeli Li, Biao Lu, Zhenhua Tang, Xin-Gui Tang, Sheng-Guo Lu, Xiaobin Guo, Songcheng Hu, Dijie Yao, Zhigang Liu, and Jingmin Fan
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Materials science ,business.industry ,Metals and Alloys ,02 engineering and technology ,Dielectric ,Pulsed power ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Ferroelectricity ,Energy storage ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,Pulsed laser deposition ,Capacitor ,Film capacitor ,law ,visual_art ,visual_art.visual_art_medium ,Optoelectronics ,Ceramic ,0210 nano-technology ,business - Abstract
As the fundamental energy storage components in electronic systems, dielectric capacitors with high power densities were demanded. In this work, the anti-ferroelectric Pb0.89La0.06Sr0.05(Zr0.95Ti0.05)O3 (PLSZT) ceramics and thin film capacitor were successfully fabricated by a solid-state reaction route and pulsed laser deposition method, respectively. The ferroelectric, dielectric, energy-storage properties, and temperature stability of anti-ferroelectric PLSZT capacitor were investigated in detail. By compared with the PLSZT ceramic (energy storage density is 1.29 J/cm3 with an efficiency of 78.7% under 75 kV/cm), the anti-ferroelectric PLSZT thin film capacitors exhibited the enhanced energy storage density of 52.6 J/cm3 with efficiency of 67.7% under an electric field as high as 2068.9 kV/cm, and the enhanced energy-storage temperature stabilities from room temperature (RT) to more than 200 °C were demonstrated, and the oxygen defects mechanism and size effect were discussed. Moreover, the fast charging (∼0.05 μs) and discharging (∼0.15 μs) time were certified for the anti-ferroelectric PLSZT film capacitor. These findings broaden the horizon for PLSZT anti-ferroelectrics in high energy storage properties and show promising for manufacturing pulse power capacitor.
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- 2022
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47. Tailoring electrocaloric properties of Ba1-xSrxSnyTi1-yO3 ceramics by compositional modification
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Christian Molin, T. Richter, Sylvia E. Gebhardt, and Publica
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lead-free ,Materials science ,Analytical chemistry ,chemistry.chemical_element ,Dielectric ,Atmospheric temperature range ,Ferroelectricity ,electrocaloric effect ,chemistry.chemical_compound ,chemistry ,dielectric properties ,Thermocouple ,visual_art ,Barium titanate ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,doped barium titanate ,Ceramic ,Tin ,Solid solution - Abstract
This paper presents compositional modifications on lead-free material system based on barium titanate to optimize its electrocaloric (EC) properties. By addition of strontium and tin we prepared solid solutions of Ba1-xSrxSnyTi1-yO3 (BSSnT-100∙x-100∙y) which allow for shifting of maximum EC effect to room temperature as well as broadening the temperature range of high EC temperature changes Δ T E C . Bulk ceramic samples of BSSnT were prepared by solid-state reaction route and the influence of Sn:Sr ratio on dielectric and ferroelectric properties was investigated. The EC temperature change was measured directly using resistance welded thermocouple wires. Most promising results could be achieved for BSSnT-18−6.5, which showed a maximum Δ T E C of 0.49 K around 30 °C with Δ T E C > 0.3 K in the temperature range from 10 °C to 50 °C under a comparatively low electric field change of 2 V μm−1.
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- 2022
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48. Development of PVDF/Pr2O3 nanocomposite films for biomedical sensing and energy harvesting
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K. J. Arun, Mohan D. Aggarwal, Ashok K. Batra, and V.S. Hiran
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010302 applied physics ,Materials science ,Nanocomposite ,Poling ,Oxide ,Nanoparticle ,02 engineering and technology ,Dielectric ,021001 nanoscience & nanotechnology ,01 natural sciences ,Ferroelectricity ,Polyvinylidene fluoride ,Pyroelectricity ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,0103 physical sciences ,0210 nano-technology - Abstract
Ferroelectric Polyvinylidene fluoride (PVDF) and its copolymers are used in a wide range of devices due to their excellent mechanical properties, high thermal and chemical stability, piezoelectric and pyroelectric responses. In the present investigation, Praseodymium oxide (Pr2O3) nanoparticles were synthesized hydrothermally and embedded in PVDF and films were fabricated by solution casting method. Enhancement of technologically important β-phase is observed in nanocomposite films. Electro active β and γ phase fractions are increased tremendously without poling and annealing is the highlight of the present work. Increased dielectric properties with low loss and enhanced photoluminescence on addition of nanoparticles are attributed to the enrichment of electro active phases.
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- 2022
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49. Enhancing the dielectric and energy storage properties of lead-free Na0.5Bi0.5TiO3–BaTiO3 ceramics by adding K0.5Na0.5NbO3 ferroelectric
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Yilin Zhang, Yan Jiao, Yingjie Fan, Gang Liu, Simeng Song, Chunlin Song, Zhaoyu Yang, and Jingwen Lv
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Materials science ,Process Chemistry and Technology ,Dielectric ,Ferroelectricity ,Energy storage ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Batio3 ceramics ,Phase (matter) ,visual_art ,Electric field ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Energy density ,Ceramic ,Composite material - Abstract
A novel strategy of enhancing the dielectric and energy storage properties of Na0.5Bi0.5TiO3–BaTiO3 (NBT–BT) ceramics by introducing a K0.5Na0.5NbO3 (KNN) ferroelectric phase is proposed herein, and its underlying mechanism is elucidated. The lead-free KNN ceramic decreases the residual polarisation and increases the electric breakdown strength of the NBT–BT matrix through the simultaneous modification of its A-sites and B-sites. The obtained NBT−BT−x−KNN ceramics have a perovskite structure with unifying grains. A bulk 0.9NBT–BT–0.1KNN ceramic sample with a thickness of 0.2 mm possesses a high energy storage density of 2.81 J/cm3 at an applied electric field of 180 kV/cm. Moreover, it exhibits good insulation properties and undergoes rapid charge and discharge processes. Therefore, the obtained 0.9NBT–BT–0.1KNN ceramic can be potentially used in high-power applications because of its high energy density, good insulation properties, and large discharge rate.
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- 2022
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50. Dielectric and magneto-dielectric properties of x [Co0.9Ni0.1Fe2O4] - (1-x) [Ba(Zr0.2Ti0.8)O3] particulate multiferroic composites
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Sanjay G. Chavan, Chandrakant B. Kolekar, Sagar M. Mane, Pravin M. Tirmali, Dadasaheb J. Salunkhe, and S. B. Kulkarni
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Diffraction ,Materials science ,Polymers and Plastics ,Transition temperature ,Ferrite (magnet) ,Dissipation factor ,Multiferroics ,Dielectric ,Composite material ,Ferroelectricity ,General Environmental Science ,Magnetic field - Abstract
Present paper reports on synthesis and characterization of x(Co0.9Ni0.1Fe2O4)-(1-x)(Ba(Zr0.2Ti0.8)O3) multiferroic magneto-dielectric composite of ferrite and ferroelectric phase for x=0.1, 0.2 and 0.3 via hydroxide co-precipitation method. The well compacted disc shape samples of the MD composites are sintered with microwave sintering technique at 1100°C. These composites are investigated for their structural, micro-structural, dielectric, ferroelectric and magneto-dielectric properties. X-ray diffraction shows the presence of the peaks corresponding to both ferroelectric and ferrite phases in the composites. Temperature dependent dielectric spectra gives the two anomalies one at lower temperature (below 50°C) corresponds to the ferroelectric transition temperature and other at the higher temperature (above 350°C) corresponding to magnetic transition. The variation of dielectric constant and loss tangent with applied magnetic field between 0-1 tesla in the frequency range of 500 Hz to 1 MHz are investigated. Dielectric constant possesses contribution due to magnetic field dependent interfacial polarization and variations due to the induced stress which can be explained on the observed MD effect. Copyright © 2016 VBRI Press
- Published
- 2021
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