Search

In this work, we report a giant strain (0.42%) in lead-free ceramics of (1– x) (0.79Bi 0.5 Na 0.5 TiO 3 –0.20 Bi 0.5 K 0.5 TiO 3 –0.01NaNbO 3)– x SrTiO 3 with x =0.03. Most importantly, ultra-high temperature stability was simultaneously achieved under this giant strain with the variation less than 10% in the range of 20 °C and 140 °C. Systematic temperature dependent Raman spectra measurements and Ginzburg–Landau–Devonshire thermodynamic theory analysis revealed that the intrinsic lattice strain and electric field induced relaxor-ferroelectric phase transition provide reverse strain response with the increase of temperature, jointly conducive to the ultra-high temperature stability of strain property. These materials are extremely competitive in practical application of actuators. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The electric field dependence on the dielectric properties of the porous ceramics was studied theoretically. The dielectric constant of the porous ceramics under certain direct current (dc) bias field and the real strength electric field in the porous ceramics were given quantitatively. As the pore can share the electric field, the tunability of the porous ceramics will be decreased when the porosity increases. The dielectric constant evolution of Ba0.6Sr0.4TiO3-based porous ceramics with the dc bias electric field can be successfully explained by our theoretical results. Taking Ba0.6Sr0.4TiO3-based porous ceramic samples, for example, there is good correspondence between the theoretical and the experimental results. [ABSTRACT FROM AUTHOR]

With the continuous development of electronic devices, miniaturization and high capacitance have become important factors in the fabrication of multilayer ceramic capacitors (MLCCs) with a Ni internal electrode (Ni-MLCCs). The typical thickness of the dielectric layer of commercial MLCCs is less than 1 μm, which implies a higher capacitance compared to MLCCs with a thicker dielectric layer. In this study, 1210-type Ni-MLCCs were prepared via a tape casting method using a BaTiO 3 powder chemically coated with Dy and Ho additives. The high capacitance (390 nF) Ni-MLCC sintered at 1220 °C exhibited a low dielectric loss (tan δ < 2%), high insulation resistance (>9000 MΩ), and temperature stability comparable to that of the EIA X5R standard (capacitance-temperature coefficient (TCC) = ΔC/C 25 °C ≤ ±15%, between -55–85 °C). Relaxation behavior was observed between 1 Hz and 10 kHz, following the modified Curie–Weiss law and the Vogel–Fulcher relationship. The capacitive temperature stability of Ni-MLCC is closely related to the applied direct current (DC) bias field. The EIA X7R stability (TCC ≤ ±15%, between -55–125 °C) of the Ni-MLCCs at 1220 °C was gained under dc-bias field 3 and 5 V/μm. The capacitance varied as alternating current (AC) electric fields were applied. The grain shell was sensitive to both the DC bias and AC fields, but the grain core was more sensitive to the DC bias electrical field than the AC field. Furthermore, the ferroelectric response in MLCC decreases with rising temperature. [ABSTRACT FROM AUTHOR]

The ferroelectric hysteresis loops of 63PbTiO3-37BiScO3 ceramics were measured under sinusoidal electric fields in the range of frequency from 0.1 to 100 Hz and field from 5 to 55 kV/cm. The fitting results showed two linear relations existed between the logarithm of hysteresis area and the logarithm of the amplitude of field E0 in the first and third field region. In the second region, no linear relation existed due to polarization reversal. These three-stage behaviors were distinct from the existing two-stage behaviors. The slopes in the third stage increase with the increasing of frequency, which can be attributed to dielectric loss under high frequency. [ABSTRACT FROM AUTHOR]

The electric field (E) controlled magnetism in the multiferroic heterostructure comprising polycrystalline yttrium iron garnet (YIG) film, Pt electrodes, and lead magnesium niobate-lead zirconate titanate (PMN-PZT) ceramic is presented in this work. The electric-field-dependent magnetization and susceptibility of YIG film reveal the strain-mediated transformation of magnetocrystalline anisotropy. A strong converse magnetoelectric (CME) effect has been observed in the YIG/Pt/PMN-PZT/Pt heterostructure, and the CME coefficient can reach 17 × 10−8 s/m at 0 Oe and 4.2 kV/cm. The reversible magnetization switching by means of a low voltage pulse (±4.6 kV/cm) can be realized at 0 Oe in the YIG/Pt/PMN-PZT/Pt heterostructure, and the E-tunable susceptibility can reach Δχ/χ0+ = 55.5% at 20 Oe and 4 kV/cm. These results show great potential in power-efficient magnetoelectric components for information storage and tunable devices. [ABSTRACT FROM AUTHOR]

The artificial multiferroic heterostructure used in this work is composed by an yttrium iron garnet (YIG) film deposited by radio frequency (rf) magnetron sputtering on a metalized PMN-PZT ceramic. We demonstrate, thanks to the well-known converse magnetoelectric (CME) coupling, the control of the magnetic state of the YIG film by means of a low electric field applied to the PMN-PZT ceramic. In particular, it is shown that the variations of the magnetization induced by the strain are functions of the magnetic sate of the film. It is shown that the maximum amplitude variation is observed at the coercive magnetic field (Hc), whereas when H increases, the strain effect has a limited impact on the film magnetization. A second effect has also been remarked on the magnetization of the YIG film but only after the first strain induced cycle has been applied. These variations, observed only under low applied magnetic fields, can be attributed to the re-orientation of some magnetic moments which are easy to switch under low magnetic fields. We find that after poling the YIG film, i.e., applying a magnetic field on it, the initial state is restored. The CME coupling coefficient is determined for different magnetic states of the YIG film, and the maximum value 11 × 10−8 s/m is obtained at H = Hc and E = Ec (the coercive field of the PMN-PZT ceramic). The relative susceptibility tunability available for the heterostructure proposed is 16.8% for an electric field applied between 0 and −4 kV/cm. [ABSTRACT FROM AUTHOR]

Abstract: The ferroelectric hysteresis loops of (1− x)BiScO3–xPbTiO3 (BSPT) ceramics with different phase structure were measured under sinusoidal electric fields. Three-stage behaviors between ln〈A〉 (〈A〉 is hysteresis loop area) and ln E 0 (E 0 is the amplitude of field) were identified with the increasing of E 0. These three-stage behaviors reflected different polarization behavior in each stage, which were distinct from the existing two-stage behavior. The shifting of dividing points between two stages with the evolution of phase structure revealed that in the tetragonal phase domain switching has a higher activation field due to the different domain structure. [Copyright &y& Elsevier]

The ferroelectric hysteresis loops of 63PbTiO3-37BiScO3 bulk ceramics were measured under sinusoidal electric fields over a frequency range of 1 Hz-100 Hz and amplitude range of 10 kV/cm-50 kV/cm. Scaling relation of ferroelectric hysteresis loops area 〈A〉 versus frequency f and the amplitude of field E0 for the saturated loops is [image omitted], while the scaling relation for the unsaturated loops takes the form of [image omitted]. [ABSTRACT FROM AUTHOR]

Ceramic‐based dielectric capacitor are highly suitable for pulsed power applications due to their high power density and excellent reliability. However, the ultrahigh applied electric field limit their applications in integrated electronic devices. In this work, (1−x){0.96(Bi0.5Na0.5)(Ti0.995Mn0.005)O3‐0.04BiAlO3}‐xNaNbO3 (BNT‐BA‐xNN, x = 0, 0.04, 0.08, 0.12, and 0.16) ternary ceramics were designed to achieve excellent energy storage properties. It was found that the introduction of NaNbO3 (NN) effectively increase the difference (ΔP) between Pmax and Pr, resulting in an obvious enhancement of the energy storage properties. High recoverable energy storage density, responsivity, and power density, that is, Wrec = 2.01 J/cm3, ξ = Wrec/E = 130.69 J/(kV⋅m2), and PD = 25.59 MW/cm3, accompanied with superior temperature stability were realized at x = 0.14 composition. In addition, the thermal stable dielectric properties of the sample can be prominently improved with increasing NN content. The temperature coefficient of capacitance (TCC) of x = 0.16 composition is lower than 15% over the temperature range from 49°C to 340°C, with a high dielectric permittivity of 1647 and a low dielectric loss (0.0107) at 150°C. All these features show that the BNT‐BA‐xNN ceramics are promising materials for energy storage application. [ABSTRACT FROM AUTHOR]

The grinding strain induced ferroelectric (FE) to antiferroelectric (AFE) phase transition with associated hysteresis loops tuning were found in bulk Pb 0.99 (Zr 0.97 Ti 0.03) 0.98 Nb 0.02 O 3 ceramics. The induced AFE phases can keep stable unless applying heat treatment or electric field. The atomic-scale characterizations reveal that the perfect coherent FE/AFE interface appears either diffuse or sharp depending on its relative orientation to polarization. The induced surface AFE layers on FE bulk can tune hysteresis loops from symmetric to asymmetric and this effect increased with the decrease of thickness of samples. These findings provide new pathway for manipulate phase state and discover novel properties in ferroics. Grinding strain induced ferroelectric-antiferroelectric phase transition with hysteresis loops tuning in bulk ceramics. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Antiferroelectrics (AFE) are considered a promising energy storage material for components that require nanosecond-level discharge. Pb(Yb 1/2 Nb 1/2)O 3 (PYN) is an AFE material with potential energy storage applications. However, the unmatched critical phase transition field (E F) and breakdown electric field (E B) conceal most of energy storage capacitance. This work is aimed to settle imbalanced E F / E B via a compositional design strategy. E F and E B were tuned in order to obtain 5.18 J cm−3 in recoverable energy density, 65% energy efficiency, and thermal and frequency stability varying within 15%, producing excellent comprehensive energy storage properties. A modified kinetic model of energetic path was used to understand the mechanism governing the variation of E F. We expect our work to contribute to further development of novel AFE materials for energy storage. [ABSTRACT FROM AUTHOR]

A magnetoelectric (ME) heterostructure was fabricated by depositing a Ni‐Mn‐Ga (NMG) magnetic film on an antiferroelectric (AFE) PLZST—(Pb, La)(Zr, Sn, Ti)O3—ceramic substrate. Significant and reversible electric field‐induced relative magnetization changes (∆M/M0) were firstly observed in this magnetic/AFE heterostructure, and the ∆M/M0 vs electric field loops have been found to correspond well with the strain‐electric field curve of PLZST ceramic. The maximum ∆M/M0 variation can reach 15%, indicating an obvious strain‐mediated converse magnetoelectric (CME) effect. A maximum CME coefficient of 1.14 × 10‐9 s/m was obtained at the switching electric fields of PLZST. The collected results suggest that AFE materials with a large electric‐field‐induced phase transition strain could be alternative candidates in ME coupling heterostructures. [ABSTRACT FROM AUTHOR]

We report the electric-field-induced ferroelectric (FEIN) to antiferroelectric (AFE) phase transition that is tuned by the poling temperatures in 0.89Bi0.5Na0.5TiO3-0.06BaTiO3-0.05K0.5Na0.5NbO3 (0.89BNT-0.06BT-0.05KNN) ceramics. Phase transition and pyroelectric behaviors of the ceramics were investigated as functions of temperature and electric field. Pyroelectric coefficient peaks of (3 ∼ 6.5) × 10-8 C cm-2 K-1 are detected at about 10 °C above the poling temperatures for the samples poled at different temperatures. The poling temperature tuned pyroelectric behaviors are attributed to the FEIN to AFE phase transition when the temperature increases. [ABSTRACT FROM AUTHOR]

Abstract Currently, there is an urgent need of extraordinary comprehensive pyroelectric materials for the wide application in detectors and energy harvesters. In this study, the (Pb 1–1.5 x La x)(Zr 0.86 Ti 0.14)O 3 (abbreviated as PLZT, x = 0.02, 0.03, 0.04 and 0.05) ceramics located in ferroelectric-antiferroelectric (FE-AFE) phase boundary were designed and synthesized by using conventional solid-state reaction method. The microstructures, phase structures, dielectric, ferroelectric, thermal depolarization and pyroelectric properties of the PLZT ceramics with different La content were investigated thoroughly. The XRD results show that the PLZT ceramics change from FE phase to AFE phase with increasing La content. The significant improvement of pyroelectric coefficient p and figures of merit (FOMs) are achieved in the PLZT ceramics with the increase in La content because of the increased metastable ferroelectric phase under the application of electric field. The (Pb 0.955 La 0.03)(Zr 0.86 Ti 0.14)O 3 (x = 0.03) ceramic exhibits not only high p of 5.2 × 10 − 8 C / cm 2 K and high depolarization temperature (T d) of 179 ℃ but also excellent FOMs with F i = 2.2 × 10 − 10 m / V , F v = 5.0 × 10 − 2 m 2 / C , and F d = 3.47 × 10 − 5 Pa − 1 / 2 . In addition, the highest p of 6.8 × 10 − 8 C / cm 2 K is achieved in (Pb 0.94 La 0.04)(Zr 0.86 Ti 0.14)O 3 (x = 0.04) ceramic. These results demonstrate that the PLZT ceramics of x = 0.03 and 0.04 are promising candidates for pyroelectric applications. [ABSTRACT FROM AUTHOR]

Well-defined polarization-electric field double hysteresis loops are rarely observed in pure NaNbO3 (NN) ceramics due to the metastability of the field-induced ferroelectric phase. In order to stabilize the antiferroelectric phase, various ABO3-type binary oxides were incorporated into a NaNbO3 ceramic, where the B-site is occupied with transition elements. In this work, CaSnO3 was chosen to construct the NaNbO3-based solid solution by reducing the Goldschmidt tolerance factor and ionic polarizability. X-ray diffraction patterns, transmission electron microscopy images, and Raman spectra indicate enhanced antiferroelectricity. Typical double hysteresis loops were also observed from polarization-electric field measurements in ambient conditions with slightly weakened maximum polarization as the content of CaSnO3 increased. Our results reveal the generality of this strategy and pave the way for various applications involving high-power energy for NaNbO3-based ceramics. [ABSTRACT FROM AUTHOR]

The electrical hysteresis behaviors and energy storage performance of Pb0.97La0.02(Zr0.58Sn0.335Ti0.085)O3 antiferroelectric ( AFE) ceramics were studied under the combined effects of electric field and temperature. It was observed that the temperature dependence of recoverable energy density ( Wre) of AFE ceramics depends critically on the applied electric field. While Wre at lower electric fields (<8 kV/mm) shows increasing tendency with increasing temperature from 20°C to 100°C, Wre at higher electric fields (>8 kV/mm) demonstrates decreasing dependence. There exists an appropriate electric field (8 kV/mm) under which the AFE ceramics exhibit nearly temperature-independent Wre (the variation is less than 0.5% per 10°C). The underlying physical principles were also discussed in this study. These results indicate that the temperature dependence of Wre of AFE materials can be tuned through selecting appropriate electric fields and provide an avenue to obtain thermal stable energy storage capacitors, which should be of great interest to modern energy storage community. [ABSTRACT FROM AUTHOR]

Reversible domain switching in aged acceptor-doped ferroelectric ceramics is a powerful method to achieve electrostrain due to the exchange of nonequal crystalline axes of domains. Nevertheless, previous work suggested that the strain obtained via reversible domain switching in unpoled ceramics was much lower than theoretical value. In this paper, we demonstrate that the strain in poled and aged acceptor-doped ferroelectric ceramics can be significantly enhanced when the driving electric field is perpendicular to the poling direction, originating from the exchange of nonequel crystalline axes of more domains. Consequently, the electrostrain of poled and aged 0.1 wt% MnO 2 -doped 0.05Pb(Mn 1/3 Sb 2/3 )O 3 −0.50PbZrO 3 −0.45PbTiO 3 could reach 0.225% which was 4.17 times larger than that of unpoled sample under a low electric field of 15 kV cm −1 . Moreover, the corresponding normalized strain d 33 * reached 1500 pm V −1 which significantly exceeded the values reported in ferroelectric ceramics. Our work provide a general effective method to enhance the electrostrain behavior via reversible domain switching in aged acceptor-doped ferroelectric ceramics. [ABSTRACT FROM AUTHOR]

The dynamic hysteresis scaling behaviors of Nb-doped Pb(Zr0.52Ti0.48)O3 ceramics have been investigated as a function of electric field amplitude ( E0) and frequency ( f) at different temperatures ( T). The loop area of saturated loops is found to follow various power laws as ∝ E00.3065 at fixed f and ∝ f 0.0120 at fixed E0. Furthermore, the linear scaling relation = k3 fα E0β + b3 is estimated under various temperatures. The exponents α (=0.01) and β (=0.10) are T-independent, whereas the slopes k3 and y-intercepts b3 are T-dependent because the increasing temperature in the same phase range only decreases the threshold field of the reversal rather than change the dynamic reversal process. [ABSTRACT FROM AUTHOR]

In this study, we investigated the scaling behavior of dynamic hysteresis with frequency f and electric field E in epitaxial PbZrO 3 antiferroelectric film on (111)-oriented SrTiO 3 substrate. The scaling relation for the saturated hysteresis loops takes the form of hysteresis area ∝ f 0.03 ( E − 499) 0.20 at relatively low testing f . However, when frequency exceeds 30 Hz, the shows stronger dependence on f while remains basically unchanged relation with E , leading to a form of ∝ f 0.10 ( E − 499) 0.20 . The scaling behavior is modeled as occurring in a viscous medium where several forces, such as viscous and restoring forces, act on the phase transition process. [ABSTRACT FROM AUTHOR]

Energy-storage properties of 0.89 Bi0.5Na0.5TiO3-0.06 BaTiO3-0.05 K0.5Na0.5NbO3 (0.89 BNT-0.06 BT-0.05 KNN) lead-free ceramics were first investigated. Measurements of dielectric properties together with switching current curves indicate a rather diffuse ferroelectric ( FE) to anti-ferroelectric ( AFE) phase transition when heating from 20°C to 90°C. The energy density ( W), which was calculated from P-E hysteresis loops, increases linearly with the external electric field when E exceeds AFE- FE transition field. W is independent of temperature and frequency, and maintains around 0.59 J/cm3 under 5.6 kV/mm in the stable AFE phase region. These properties indicate that 0.89 BNT-0.06 BT-0.05 KNN ceramics might be a promising lead-free AFE material for energy-storage capacitor application. [ABSTRACT FROM AUTHOR]

Abstract: Porous Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 ferroelectric ceramics with different pore size were prepared by solid-state sintering in air. The microstructural effect on the properties has been systematically investigated by SEM, ferroelectric hysteresis, strain–electric field curves and breakdown strength measurements. The results demonstrate that the microgeometry has a subtle effect on the ferroelectric and dielectric properties. However, the results also demonstrate that the electric field induced strain and the dielectric breakdown strength decreases with the increase of pore size. [Copyright &y& Elsevier]

Abstract: Polarization–field (P–E) hysteresis loops of – bulk ceramics were measured under sinusoidal electric fields over a frequency range of Hz and an amplitude range of 20–50 kV/cm. The scaling relations of the hysteresis loop area versus the frequency and amplitude of the applied field for the saturated loops take different forms in the low and high frequency ranges. From these two relations, it can be concluded that the relationship is a power law increase in the low frequency range while in the high frequency range the relationship turns into a power law decrease. [Copyright &y& Elsevier]

The effect of residual stress on energy storage property was investigated for a series of PbZrO3 thin films on SrTiO3 and Si substrates. Compressive or tensile residual stress influences the critical electric field EA for the ferroelectric-to-antiferroelectric phase transition, thus for films with (110)/(101) orientation, energy density W of films on SrTiO3 is 38% larger than films on Si; in contrast, (001)-oriented PbZrO3 films on SrTiO3 show slightly smaller W compared to films on Si. We conclude that the different responses of W to stress are related to the different constrain states in films with different orientations. [ABSTRACT FROM AUTHOR]

Large strain memory effect was confirmed in the poled and aged Mn-doped 0.05Pb(Mn1/3Sb2/3)O3-0.50PbZrO3-0.45PbTiO3 ceramics due to the presence of asymmetric strain hysteresis curve with two stable strain states at zero electric field. This strain memory is two times larger than that of the unipolar strain output. Moreover, the large strain memory effect is quite stable at high electric field or down to 0.01 Hz and shows good stability even after 20 000 fatigue cycles. These results indicate that strain memory piezoelectric actuator, which could keep its output strain without any operating fields, may be fabricated using this kind of material. [ABSTRACT FROM AUTHOR]

(Pb0.325Sr0.675)TiO3 (PST) ceramics were prepared by a traditional solid-state reaction technique. The dielectric and enhanced pyroelectric properties of PST ceramics were investigated under a DC bias field. The dielectric permittivity and dielectric loss of PST ceramics at Curie temperature were 2.97 × 10-4 and 0.006 without DC bias field, respectively. With a DC electric field of 0-500 V/mm, the maximum pyroelectric coefficient and the largest figure of merit (Fd) of PST ceramics were obtained, about 60 × 10-8 C cm-2 K-1 and 26 × 10-5 Pa-1/2, respectively. PST ceramics with such superior electric field enhanced pyroelectric properties have the potential for uncooled focal plane array detectors application. [ABSTRACT FROM AUTHOR]