Polarization-electric Field Loops Research Articles

Piezoelectric Nanogenerator Based on Lead-Free Flexible PVDF-Barium Titanate Composite Films for Driving Low Power Electronics

Self-powered sensor development is moving towards miniaturization and requires a suitable power source for its operation. The piezoelectric nanogenerator (PENG) is a potential candidate to act as a partial solution to suppress the burgeoning energy demand. The present work is focused on the development of the PENG based on flexible polymer-ceramic composite films. The X-ray spectra suggest that the BTO particles have tetragonal symmetry and the PVDF-BTO composite films (CF) have a mixed phase. The dielectric constant increases with the introduction of the particles in the PVDF polymer and the loss of the CF is much less for all compositions. The BTO particles have a wide structural diversity and are lead-free, which can be further employed to make a CF. An attempt was made to design a robust, scalable, and cost-effective piezoelectric nanogenerator based on the PVDF-BTO CFs. The solvent casting route was a facile approach, with respect to spin coating, electrospinning, or sonication routes. The introduction of the BTO particles into PVDF enhanced the dielectric constant and polarization of the composite film. Furthermore, the single-layered device output could be increased by strategies such as internal polarization amplification, which was confirmed with the help of the polarization-electric field loop of the PVDF-BTO composite film. The piezoelectric nanogenerator with 10 wt% BTO-PVDF CF gives a high electrical output of voltage 7.2 V, current 38 nA, and power density of 0.8 μW/cm2 at 100 MΩ. Finally, the energy harvesting using the fabricated PENG is done by various actives like coin dropping, under air blowing, and finger tapping. Finally, low-power electronics such as calculator is successfully powered by charging a 10 μF capacitor using the PENG device.

Optimization of polarization and electric field of bismuth ferrite-based ceramics for capacitor applications

• Optimization of polarization and electric field for BF-based ceramics. • High W rec of 5.57 J cm −3 was achieved for BFBT-NBN ceramics at 410 kV cm −1 . • The η maintain ~89% and the variation of W rec is less than ±2% after 10 4 cycles. • Energy storage properties of the BFBT-NBN ceramics exhibit outstanding stability. For the purpose of meeting the requirements of protecting environment and sustainable development, bismuth ferrite (BiFeO 3 , BF)-based lead-free ceramics have gained immense attention for pulsed power capacitor applications due to their large spontaneous polarization, low sintering temperature as well as non-toxic and harmless. However, the low energy storage properties (ESPs) and unstable performance of BF-based ceramics are not good for practical applications. In this work, novel bismuth ferrite-based lead-free ceramics of (1-x)(0.67BiFeO 3 -0.33BaTiO 3 )-xNa 0.73 Bi 0.09 NbO 3 ((1-x)BFBT-xNBN) were designed and fabricated successfully by optimizing the polarization and electric field. With increasing the content of NBN, the remnant polarization decreased rapidly as well as the slim and pinched polarization-electric field loops together with high electric field can be observed. Notably, ultrahigh ESPs with the total energy storage density (W tot ) of 6.65 J cm −3 and the recoverable energy storage density (W rec ) of 5.57 J cm −3 can be achieved at high electric field of 410 kV cm −1 . At the same time, the η is greater than 80% and the variation of W rec is less than ±5% over a broad frequency range (1–100 Hz) and temperature range (30–150 °C). In addition, the η is stabilized around 89% and the variation of W rec is less than ± 2% after 10 4 cycles. Therefore, the (1-x)BFBT-xNBN lead-free ceramics not only possess ultrahigh ESPs but also the ESPs exhibit outstanding stability, which is promising candidates for high performance pulsed power capacitor applications.

Enhanced voltage endurance capability of Ba(Zr0.2Ti0.8)O3 thin films induced by atomic-layer-deposited Al2O3 intercalations and the application in electrostatic energy storage

Ultrathin Al2O3 insulating intercalations with different thicknesses and numbers, prepared by atomic layer deposition technology, were introduced into Ba(Zr0.2Ti0.8)O3 (BZT) relaxor ferroelectric films as the dielectric for electrostatic energy storage capacitors. The phase structure, microstructure and electrical properties were investigated in detail. Due to the insertion of insulating layers, the films show less leakage current and enhanced voltage endurance capability when the thickness of single Al2O3 intercalation exceeds a threshold (0.45–0.9 nm). The voltage endurance capability can be more enhanced by increasing the number of Al2O3 intercalations. For energy storage applications, the energy storage density and efficiency obtained from the polarization-electric field loops are significantly improved owing to the suppressed leakage and enhanced voltage endurance ability. The results promote the application of BZT-based films in electrostatic energy storage. It is demonstrated that the introduction of atomic-layer-deposited insulating intercalations with controllable thickness, such as those fabricated by ALD method, is an effective way to improve the electrical performance of devices based on composite materials.

Synergistic optimization of antiferroelectric ceramics with superior energy storage properties via phase structure engineering

Dielectric capacitors with high energy storage density and high efficiency exhibit potential applications in lightweight, miniaturized microelectronic devices. Here, (Pb, La)(Zr, Sn)O3 (PLZS) based ceramics with Ba substitution were selected and studied with in-situ Raman spectra and in-situ synchrotron X-ray diffraction. Results show that the room temperature phase structure consists of two coexisting antiferroelectric phases of OI and OII (O refers to orthorhombic), and between them the latter possesses lower forward phase-switching electric field (EAF) and should be the origin of FE(I). Meanwhile, Polarization-electric field (P-E) loops and Raman spectrum under variable temperature reveal optimal Ba content of 0.02. Suitable Ba substitution forms balanced coexisting structure and therefore achieves ultrahigh recoverable energy storage density (Wrec) of 12.8 J/cm3 and simultaneously high energy storage efficiency (η) of 84.2% under an electric field of 450 kV/cm. Extremely short discharge period of 51.6 ns and high Wrec support ultrahigh power density (PD) of 327 MW/cm3 and high discharge current density (Ddis) of 1815 A/cm2. Reasonable phase structure design after clarifying the relationship between structure and performance shows guiding significance, and the improved ultra-high Wrec and PD enhance the possibility of applications of antiferroelectric ceramics in pulsed power capacitor.

Ferroelectric polarization induced memristive behavior in bismuth ferrite (BiFeO3) based memory devices

Bismuth ferrite (BiFeO 3 , BFO) thin films of various thickness were deposited using spray pyrolysis technique at 673 K. The structural studies of the prepared BFO thin films show a rhombohedral structure with R3c space group. The morphological analysis reveals that prepared BFO thin film samples exhibit a uniform and less porous grains. Different thickness of BFO thin films (174–808 nm) was stacked as an active layer between aluminum (Al) and indium doped tin oxide (ITO) electrodes . With the optimum thickness of the BFO intermediate layer, the polarization-electric field (P-E) loop analysis of the ITO/BFO/Al device showed a hysteresis loop with remnant polarization (P r ) of 0.21 μC/cm 2 and coercive field (E c ) of 33.4 kV/cm respectively. The impact of the BFO switching layers with varying thickness towards control of oxygen vacancy (V O ) defects and the effective role of polarization induced resistive switching (RS) characteristics were explored. • Realization of BFO resistive switching layers by cost-effective spray pyrolysis technique. • XPS analysis of different thickness of BFO layers to study the control of oxygen vacancy (V O ) defects. • The effective role of polarization in BFO layers towards resistive switching (RS) characteristics were explored.

Preparation and dielectric properties of order nanoporous TiO2/PAA film

Polycrystalline order nanoporous TiO2/PAA (porous anodic alumina) composite films have been prepared by reactive DC magnetron sputtering technique at room temperature. The crystalline phase and morphology of the deposited film were investigated by X-ray diffraction spectra (XRD) and scanning electron microscopy (SEM), respectively. The results showed that the post-annealing treatment could facilitate film crystallization. The influences of pore diameter and electric field frequency on the dielectric properties of TiO2/PAA samples were systematically studied. It was found that the dielectric properties of the films depended on the pore diameters. The unipolar polarization–electric field loops for all the samples were evaluated. Interestingly, lower remnant polarization was found in the bigger pore diameter TiO2/PAA composite films, suggesting high energy storage and low loss of the sample.

Excellent energy storage properties over a wide temperature range under low driving electric fields in NBT-BSN lead-free relaxor ferroelectric ceramics

To develop environment-friendly dielectric capacitors with low working electric field and wide useable temperature, in this work, we fabricate (1-x)Na0.46Bi0.54TiO3- xBaSnO3((1-x)NBT-xBSN) lead-free relaxor ferroelectric ceramics by adding BaSnO3 into Na0.46Bi0.54TiO3 matrix. BSN exhibits slim polarization-electric field (P-E) loops, small remnant polarization (Pr) and good temperature stability because of its room-temperature paraelectric characteristics, and has different cation ionic radii with Na0.46Bi0.54TiO3. Therefore, when BSN is introduced into NBT, the relaxor behavior of the (1-x)NBT-xBSN ceramics is more pronounced and the P-E loops are much slimmer. Besides, because the substitution of Ba2+ ions with higher valence for Na+ ions neutralizes the hole carriers, which are caused by the volatilization of Na2O, the resistivity and breakdown strength are improved with increasing BSN content. As a consequence, at x = 0.30, the ceramic exhibits simultaneously a large recoverable energy density (Wrec) of 1.51 J/cm3 and high energy efficiency (η) of 81.2% at a low driving electric field of 145.3 kV/cm because of the collaborative enhancement effect of the high breakdown strength and low remnant polarization. More interestingly, variations of the Wrec and the η for this kind of ceramic are respectively as small as 10% and 0.8% over a wide temperature range of 20–140 °C, demonstrating superior temperature stability. In this report, we provide a new and efficient way for designing and fabricating environment-friendly dielectric capacitors with good reliability and superior high-temperature energy storage capacity.

Polypyrrole-based nanocomposites architecture as multifunctional material for futuristic energy storage applications

Nanoscale designing of polymer based architectures is essential to enhance the efficiency of energy storage devices for their potential applications in modern day technology. Usually, two phase nanocomposites develop a single type of interface between matrix and filler, causing an increase in dielectric constant and high energy density at the cast of charge discharge efficiency. Herein, we report a three phase (GO/CoFe2O4/PPy) novel class of nanocomposites capable of exhibiting high energy density storage. Three different components of this nanocomposite were synthesized using Hummer’s method, sol-gel auto-combustion technique and polymerization route, separately which were then combined using solution mixing technique in the presence of 0.3 M solution of FeCl3·6H2O. The development of inverse spinel structure of CoFe2O4 and its phase stability was analyzed using X-ray diffraction. Evolution of a variety of nanoarchitectures was confirmed by a field emission scanning electron microscope and its consequences on dielectric and ferroelectric response were probed via precision impedance analyzer and precision multiferroic tester. For the identification of functional groups, Fourier transform infrared spectroscopy was employed and conductive nature was examined using their I–V response curves. Dielectric response of PPy mediated by GO and CFO contents was explained on the basis of Maxwell-Wagner model. The magnetic hysteresis loops were employed and maximum magnetization, remnant magnetization, coercivity and squareness ratio were measured. Using polarization-electric field loops, energy density measurements were carried out which revealed the potential of these nanocomposites for energy storage devices.

Semiconductor/relaxor 0–3 type composites: A novel strategy for energy storage capacitors

Abstract We report a novel strategy to enhance the dielectric breakdown strength and the energy storage performance of lead-free relaxor ferroelectric ceramics through the fabrication of semiconductor/relaxor 0–3 type composites based on 0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3 [BZCT] and ZnO. X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM) measurements confirm the formation of semiconductor/relaxor 0–3 type composites, in which ZnO particles are randomly distributed at the grain boundaries of BZCT. Further, the XRD analysis suggests a structural phase change from a tetragonal to a pseudocubic phase as the ZnO content increases from 0 to 5 wt. % in BZCT/ZnO composites. The pseudocubic phase favors the relaxor behavior of the composites as is evident from dielectric studies. The polarization-electric field (P-E) loops reveal the ferroelectric nature of the BZCT/ZnO composites. The energy storage properties of BZCT/ZnO composite ceramics as a function of different wt. % of ZnO are found to be optimum at 1 wt. % with a recoverable energy density of 2.61 J/cm3 and an efficiency of 74.2%, at an electric field of 282 kV/cm. Besides, an enhancement of 166% in the electric breakdown and 220% in the recoverable energy density was achieved compared to the BZCT ceramics due to the improved density and the large value of ΔP = Pm - Pr (25.55 μC/cm2). Therefore, this work evidences that the formation of the semiconductor/relaxor 0–3 type composites can be an effective way to significantly improve the energy storage performance of lead-free relaxor ferroelectric ceramics.

Studies of structural and electrical properties of lead-free ceramic: Bi(Ba0.25Ti0.25Fe0.5)O3

Bismuth barium ferric titanate Bi(Ba0.25Ti0.25Fe0.5)O3 has been fabricated through a conventional solid-state reaction route. By means of various experimental techniques, the material has been characterized in different experimental conditions. Study of crystal structure using X-ray diffraction data determines the tetragonal system. The detailed studies of dielectric, impedance, conductivity of Bi(Ba0.25Ti 0.25Fe0.5)O3 in a broad range of temperature (25 – 380°C) and frequency (1kHz –1MHz) have provided a range of exciting results on structure and correlation properties, conduction mechanism, etc. The existence of ferroelectricity in the material is confirmed by the polarization-electric field loop analysis. At low-frequencies and high- temperatures, space charge polarization and the Maxwell–Wagner dielectric relaxation have been observed. The grain and grain boundary effects in the ceramic sample have been studied from the Nyquist plots. The study of temperature-frequency dependence of transport properties (conductivity) of the specimen has established type of conduction mechanism in it. The coefficient of magneto-electric coupling of the studied sample is found to be 3.79 mV cm−1Oe−1 at null magnetic field.

High-temperature energy storage performances in (1-x)(Na0.50Bi0.50TiO3)-xBaZrO3 lead-free relaxor ceramics

In this study, in order to obtain superior energy storage performances over a wide temperature range in lead-free dielectric ceramics, we develop and prepare (1-x)(Na0.50Bi0.50TiO3)-xBaZrO3 ((1-x)NBT-xBZ) relaxor ferroelectric ceramics by introducing BaZrO3 into Na0.50Bi0.50TiO3. BZ possesses small remnant polarization (Pr) and slim polarization-electric field (P-E) loops attributed to its room-temperature paraelectric phase structure characteristic. Thus, when it is added into NBT, the P-E loops of (1-x)NBT-xBZ ceramics are slimmer, and the Pr decreases. Besides, due to the donor doping effect resulting from the replacement of Ba2+ with higher valence for the Na+, with the increase of the BZ content, the grain sizes of the ceramics gradually decrease, resulting in the enhancement of the breakdown strength (Eb). All above these are in favour of improving energy storage properties, and as a result, by adjusting the BZ content reasonably, a large recoverable energy density (Wre) of 1.56 J/cm3 and high energy efficiency (η) of 80.56% are concurrently achieved in the 0.75NBT-0.25BZ ceramic. More interestingly, the ceramic exhibits excellent high-temperature energy storage capacity, which is superior to those of recently reported dielectric ceramics, and good fatigue properties. All these indicates that 0.75Na0.50Bi0.50TiO3-0.25BaZrO3 lead-free relaxor ferroelectric ceramic is a good candidate for preparing dielectric capacitors applicable in various environmental conditions.

Recent Progress in the Nanoscale Evaluation of Piezoelectric and Ferroelectric Properties via Scanning Probe Microscopy.

Piezoelectric and ferroelectric materials have garnered significant interest owing to their excellent physical properties and multiple potential applications. Accordingly, the need for evaluating piezoelectric and ferroelectric properties has also increased. The piezoelectric and ferroelectric properties are evaluated macroscopically using laser interferometers and polarization–electric field loop measurements. However, as the research focus is shifted from bulk to nanosized materials, scanning probe microscopy (SPM) techniques have been suggested as an alternative approach for evaluating piezoelectric and ferroelectric properties. In this Progress Report, the recent progress on the nanoscale evaluation of piezoelectric and ferroelectric properties of diverse materials using SPM‐based methods is summarized. Among the SPM techniques, the focus is on recent studies that are related to piezoresponse force microscopy and conductive atomic force microscopy; further, the utilization of these two modes to understand piezoelectric and ferroelectric properties at the nanoscale level is discussed. This work can provide guidelines for evaluating the piezoelectric and ferroelectric properties of materials based on SPM techniques.

Influence of various sintering parameters and the temperature dependent scaling on the dynamic hysteresis behavior of Ba0.9Ca0.05Sr0.05T0.85Zr0.15O3 ceramics

PurposeThe article explores the effect of sintering temperature on the ferroelectric hysteresis behavior of the synthesized ceramic material Ba0.9Ca0.05Sr0.05T0.85Zr0.15O3 (BCSTZO). It describes how the sintering temperature and its holding time have effect on the polarization-electric field (P-E) loops which is an important characteristic of a ferroelectric material. From the P-E loops obtained, various representative parameters like remnant polarization and coercive field values were extracted and scaling results were systematically established using them.Design/methodology/approachThe present article describes the establishment of scaling relations for coercive field (Ec), remnant polarization (Pr) and back switching polarization (Pbc) as a function of temperature which have been obtained from P-E loops sintered at various temperature and time. This is because sintering temperature plays a pivotal role in determining the hysteresis parameters.FindingsThe temperature dependent scaling of Ec and Pr at sintering temperature of 1400, 1425, 1450 and 1475 °C yields EcαT0.40, EcαT0.80, EcαT0.47, EcαT0.29 and PrαT−1.72, PrαT−1.55, PrαT−1.72, PrαT−1.69 respectively. Further the scaling relations for the samples sintered at 1450 °C at different time interval of 3, 4, 5 and 6 h was also established to bring the effect of sintering in switching the ferroelectric hysteresis parameters.Originality/valueThe findings of this work will prove beneficial for the researchers working in optimization of sintering parameters and will benefit researchers selecting best material among the fabricated samples for further property enhancement. The optimized sample could be explored for multifunctional applications ranging from pyroelectric voltage to piezoelectric energy harvesting. In addition to this, the scaling results help to understand the nature of ferroelectric parameters with sintering. This may open up new avenues for studying the scaling behavior of dynamic hysteresis in synthesized material by focusing on hysteresis area as a function of applied electric fields, frequency and temperature. This reason owes to the fact that electric field and frequency are important parameters for a number of applications like sensor, transducers and medical applications.

Discharge Energy Efficiency Improvement of P(VDF-HFP) Copolymers Thin Films by Stretching and Electron Beam Irradiation

Toward improving the applications for energy-based technology, dielectric polymers is getting attention due to its relatively high dielectric constant, dielectric breakdown and flexibility, with easily preparation, lightweight and low cost. Dielectric contribution and polarization responses lead to different shape and size of hysteresis loop. This work presents the techniques on reducing domain size for slimmer loop, indicating lower energy loss. As-casted P(VDF-HFP), stretched P(VDF-HFP) and electron irradiated-stretched P(VDF-HFP) thin films were prepared by solution casting method. The irradiation was prepared by emitting electron beam. The dielectric and AC conductivity properties were investigated by LCR meter, while polarization-electric field loops were observed by P-E loop instrument. The results show that stretching and electron beam irradiation significantly increase the dielectric constant of P(VDF-HFP). Their ability on modifying the domain size leads to reduce P-E loop of P(VDF-HFP), followed by reducing energy loss but improving storage energy density and discharge energy efficiency.

Electrocaloric and electromechanical properties of (Pb,La)(Zr,Ti)O3 ceramics

The direct observation of temperature changes in (Pb,La)(Zr,Ti)O3 (PLZT) (4/90/10), (8/80/20), and (8/70/30) ceramics during cycle of applying and removing electric field were utilized to evaluate their electrocaloric effects. The temperature change under the electric field drew temperature-electric field (T-E) hysteresis loops peculiar to each material. PLZT(4/90/10) ceramics exhibited a double hysteresis peculiar to antiferroelectrics in polarization-electric field (P-E) loops. A temperature drop of −0.07 K due to the application of an electric field of 70 kV/cm was observed directly by measuring the T-E loop. This temperature drop is due to a negative electrocaloric effect. PLZT(8/80/20) and (8/70/30) ceramics exhibited slim P-E loops with constriction and typical ferroelectric loops, respectively. The temperature changes induced by a bipolar switching field of 40 kV/cm in the PLZT(8/80/20) and PLZT(8/70/30) ceramics were both positive 0.22 K. The measured T-E loops had shapes similar to those of the strain-electric field loops in samples of PLZT(8/80/20) and PLZT(8/70/30) ceramics. PLZT(8/80/20) ceramics exhibited their largest electromechanical properties at around 25 °C, and the properties then decreased with increasing temperature.

Composition dependent ferro-piezo hysteresis loops and energy density properties of mechanically activated (Pb1−xLax)(Zr0.60Ti0.40)O3 ceramics

In the present study, ferroelectric and piezoelectric nature of La substituted lead zirconate titanate was investigated to decide the optimum La content. (Pb1−xLax)(Zr0.60Ti0.40)O3 (hereinafter PLZT x/60/40) ceramics were synthesized using novel processing approach of high energy ball milling and cold isostatic pressing (CIP). This study deals with two types of hysteresis loops, polarization (P–E) and strain vs. electric field (S–E) loops. Energy density properties, remanent polarization (Pr), coercive field (Ec), piezoelectric charge coefficient (d33), internal macroscopic electric field (Ein), domain switching current (Imax) and strain hysteresis, normalized strain coefficient (Smax/Emax) were also calculated to study the behaviour of PLZT x/60/40 ferroelectrics. In addition, current vs. electric field (I–E) curves were traced not only to support P–E studies and determination of the Ec but also to confirm the ferroelectricity and domain switching characteristics studies. The PLZT 8/60/40 electro-ceramics not only show the highest Pr ~ 29.1 μC/cm2, Imax ~ 2 mA, unipolar strain ~ 0.25% and average d33 ~ 632 pm/V but also the lowest Ec ~ 9.4 kV/cm and strain hysteresis loss ~ 4%.

Enhanced Electrical and Magnetic Properties of Samarium (Sm) Doped Multiferroic Bismuth Ferrite (BFO) Ceramics

Samarium (Sm) doped modified bismuth ferrite samples Bi1-xSmxFeO3 (x = 0, 0.02, 0.05, 0.08, 0.1) were prepared by sol-gel technique. A detailed study on the electrical and magnetic properties of the samples was analyzed. X-ray diffraction patterns confirm the formation of the pure phase rhombohedral structure of bismuth ferrite. The dielectric constant (ε) and loss tangent (tan δ) show the large frequency dispersion at low frequency. AC conductivity was enhanced with Sm substitution of Bi sites. The enhancement in the ferroelectric properties was delineated by Polarization-Electric field (P-E) loops. Sm substitution of Bi improves the saturation magnetization and magneto-dielectric coefficients.

A new type of BaTiO3-based ceramics with Bi(Mg1/2Sn1/2)O3 modification showing improved energy storage properties and pulsed discharging performances

Novel lead-free ceramics of (1-x)BaTiO3-xBi(Mg1/2Sn1/2)O3 (abbreviated as (1-x)BT-xBMS, with x = 0–0.20) were fabricated through a solid-state reaction route. Introducing BMS into the BT host triggered a ferroelectric-to-relaxor phase transition, which yielded slim polarization-electric field (P-E) loops and enhanced energy-storage performances. The large recoverable energy density with 2.25 J/cm3 and high energy efficiency of 94% were obtained simultaneously under 240 kV/cm with x = 0.12. Furthermore, the energy storage characteristics of the 0.88BT-0.12BMS ceramics exhibited good temperature stability in the range of −55–150 °C, and great frequency stability in the range of 10–1000 Hz. Meanwhile, by means of pulsed charging-discharging evaluation, the 0.88BT-0.12BMS ceramics displayed a fast discharge period of 73 ns and a large power density of 27.7 MW/cm3. The results indicate that the elaborately designed 0.88BT-0.12BNS ceramics have promising potential for high-power pulsed capacitor applications.

Fabricating Piezoelectric Tape of PZT-SKN

Tape ceramics are widely used in the sensor and electronic industries. In this work, we studied the ferroelectric properties of the 0.975Pb(Zr0.52Ti0.48)O3-0.025Sr(K0.25Nb0.75)O3 tape ceramic; (PZT-SKN). We fabricated the PZT-SKN using doctor blade technique with the slurry, obtained from the calcined of PZT-SKN mixing with organic solution. The crystalline structure was investigated by using X-ray diffraction, relative density, and Vickers Hardness technique. We also determined the dielectric properties and polarization electric field loops. The results of crystalline structure show that the percentage of perovskite is 97.57 %, the relative density is 98.4 %, and Vickers Hardness is 107 MPa. At the thickness 0.89 mm, the dielectric constant temperature is 1499 at 532 °C, the remnant polarization is 17 μC cm−2, Currie temperature is 552 °C, and piezoelectric coefficient is 235 pC N−1. The PZT-SKN tape ceramic has the ferroelectric properties better than tablet ceramic.

High energy density and efficiency in (Pb,La)(Zr,Sn,Ti)O3 antiferroelectric ceramics with high La3+ content and optimized Sn4+ content

In this work, to simultaneously obtain a high recoverable energy density (Wre) and efficiency (η) in one kind of material, we investigate the effects of Sn4+ content on the energy storage capacity of (Pb0.955La0.03)(Zr0.50SnxTi0.50-x)O3 antiferroelectric (AFE) ceramics with a high La3+ content. La3+ can cause polarization-electric field (P-E) loops to narrow down, therefore, resulting in a good energy storage performance. On account of the replacement of Sn4+ with larger ion radius for Ti4+, the tolerance factor decreases, and therefore, the AFE phase stability improves. This modification results in an enhancement of the ferroelectric-antiferroelectric phase switching electric field (EA), which favours an increase in Wre. However, at the same time, with the increase of Sn4+ content, the maximum polarization decreases, which can lead to a deterioration in Wre. As a result, the optimal energy storage performance is achieved in the (Pb0.955La0.03)(Zr0.50Sn0.42Ti0.08)O3 AFE ceramic, which possesses a high Wre (3.99 J/cm3) and η (79.2%). Additionally, the Wre and η exhibit a good temperature stability from 25 to 125 °C. These results indicate that this kind of ceramic can be used to prepare dielectric capacitors for working in different environments.