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Antiferroelectric thin films have attracted blooming interest due to their potential application in energy storage areas. Pb(1−3x/2)LaxHfO3 (PLHO-x, x = 0–0.05) thin films were fabricated on Pt(111)/TiO2/SiO2/Si substrates via the chemical solution deposition method. The x-ray diffraction and high-resolution transmission electron microscopy results show that the doping of La3+, which has a smaller ion radius, leads to a slight decrease in the lattice constant and unit cell volume, which can induce the lattice distortion. In addition, the dielectric and polarization properties indicate that with an increase in the temperature or La3+ content, the antiferroelectric (AFE) I phase can transform into an AFE II phase, exhibiting a slimmer P–E loop with enhanced switching field and more pronounced polarization dispersion. Notably, PLHO-0.04 showcases excellent energy storage performance (55 J/cm3, at 2.8 MV/cm). This material also exhibits good thermal, frequency, and fatigue stability. These results suggest that the energy storage performance of PbHfO3-based films can be enhanced through the phase structure design, presenting a valuable approach to fulfill the growing demand for advanced energy storage devices. [ABSTRACT FROM AUTHOR]

Antiferroelectric and ferroelectric materials are prominent non-linear dielectric materials with significant applications across various fields. To fully understand their electrical properties, it is crucial to accurately discriminate the two phases, especially in compositions with the coexistence of antiferroelectric and ferroelectric phases. In this study, we propose an easy method for differentiating domain structures from phase coexistence based on split outskirt reflections. The proposed method addresses existing limitations in the spatial phase distribution and lays the groundwork for understanding their structure–property relationships. [ABSTRACT FROM AUTHOR]

With the developments of the electronic industry, efforts to achieve high DC insulating reliability are underway to improve the mean time to failure (MTTF) of multilayer ceramic capacitors (MLCCs). However, there are few studies on appropriate measuring methods to evaluate their different reliability characteristics quantificationally. This study measured different reliability characteristics of BaTiO 3 -based multilayer ceramic capacitors sintered at three different temperatures with highly accelerated life tests (HALTs). Kaplan–Meier survival analysis, two-parameter Weibull fitting, and a new method using a stud genetic algorithm were used to calculate their MTTF in HALT conditions, and the comparison among them was carried out to select a proper fitting way. With the appropriate method, their MTTF at the rated condition was predicted and compared. Their conduction modes were also differentiated to explain their aging sensitivities to temperature and voltage. As a result, a proper way to evaluate the sample's reliability characteristics with a bathtub curve was established, and the best sintering temperature for capacitance that is also the best for reliability at the rated condition was confirmed. Meanwhile, different conducting models of MLCCs were also proved to be related to their insulation stability. [ABSTRACT FROM AUTHOR]

Pyroelectric materials have been widely studied because of their important role in infrared detectors, sensors, thermal imaging, and other applications, among which, lead-based ceramics are extensively adopted. However, the environmental problems caused by lead-based compounds in production and processing are becoming increasingly serious. Meanwhile, the surface mounting technology is extensively employed in the electronics industry for device miniaturization and integration. However, due to its high processing temperature (∼260 °C), it makes most pyroelectric ceramic materials unsuitable for this process. Therefore, it is of great significance to develop novel high-performance lead-free pyroelectric ceramics with high depolarization temperature (>260 °C). In this work, we report the Na0.995Ag0.005NbO3-0.1%Mn (NANM) pyroelectric ceramics. The antiferroelectric–ferroelectric phase transition field and coercive field of NaNbO3 ceramics were reduced by the introduction of AgNbO3 and Mn, making it easier to induce the ferroelectric phase and realize poling in NANM ceramics. The NANM ceramics exhibited an excellent pyroelectric coefficient of 2.55 × 10−4 C m−2 K−1 and figures of merit as Fi = 0.93 × 10−10 m/V, Fv = 6.46 × 10−2 m2/C, and Fd = 2.92 × 10−5 Pa−1/2 at room temperature. More importantly, a high depolarization temperature of 280 °C was achieved, ensuring the ability to withstand high temperature during production and operation. The NANM ceramics with excellent pyroelectric properties and high depolarization temperature are expected to be a promising lead-free candidate for uncooled infrared detector applications. [ABSTRACT FROM AUTHOR]

The discharge performance of antiferroelectric (AFE) capacitors is complicated and difficult to simulate due to the nonlinear polarization behavior of AFE. In this work, a nonlinear model for pulsed discharge AFEs was proposed based on a combination of the Preisach model and Kirchhoff's law. The model was driven by the data from first-order reversal curves and direct-current-bias (DC-bias) dielectric test measurements. Thus, the discharge behavior of the AFE can be studied without actual discharge experiments. Specifically, AFE discharge waveforms were calculated and evaluated for different size parameters and external circuit parameters that were conducive to compare the properties of different AFE materials. Moreover, the size effect of the capacitor on the discharge performance was discussed, which should draw the attention of researchers to prevent exaggerated conclusions. As a consequence, this method would fill the gap of AFE discharge simulation. [ABSTRACT FROM AUTHOR]

The capacitors are in rising demand for cryogenic applications. As for now, it still remains an ongoing challenge for simultaneously achieving high energy storage density and cryogenic temperature stability. Herein, the strategy of stable backward phase transition was demonstrated in the antiferroelectric composition of (Pb0.9175La0.055)(Zr0.975Ti0.025)O3. As a result, we achieved high recoverable energy density about 10 J/cm3 with exceptional low-temperature stability from −160 to 25 °C. Multi-layer ceramic capacitors designed for pulse discharge applications also demonstrated high performance in cryogenic conditions, with the peak current fluctuations of less than 4%. Through in situ characterizations using x-ray diffraction, Raman spectra, and transmission electron microscopy, we discovered that the anisotropic structural evolution is responsible for a stable backward phase transition, providing the material with robust stability at cryogenic temperatures. These results offer a good paradigm for improving the temperature stability of antiferroelectric multi-layer capacitors to meet the rigorous demands of energy storage applications. [ABSTRACT FROM AUTHOR]

Antiferroelectric ceramics can realize ultra-high energy storage, which benefits from transformation between an antiferroelectric phase and a ferroelectric phase. Understanding the mechanism of such phase transition is the key point for building the structure-property correlation. Here, we report the observation of electric-induced devil's staircase in the course of antiferroelectric–ferroelectric phase transition in PbZrO3-based antiferroelectric ceramics by in situ transmission electron microscopy. The dynamic evolution as-revealed in both reciprocal- and real-space involves stepwise rather than monotonic increase in modulation periods along with simultaneous proliferation of nanodomains. Desynchrony of phase transition is observed for incommensurate domains with different initial modulation periods within a single antiferroelectric domain. Then, the synergistic effect of the devil's staircase and as small as possible the initial modulation period is believed to contribute to the superior energy-storage performance. These findings will be helpful for the development of theories for antiferroelectric–ferroelectric phase transition and the design of high-power antiferroelectric materials. [ABSTRACT FROM AUTHOR]

Recently, Bi0.5Na0.5TiO3-based ceramics have drawn widespread attention due to their excellent energy storage properties. Here, a comprehensive analysis of the composition- and temperature-driven transition processes in (1 − x)Bi0.5Na0.5TiO3-xSm2Ti2O7 (BNST-x) polycrystals have been presented using Raman scattering and spectroscopic ellipsometry. With increasing Sm2Ti2O7 content, BNST-x ceramic gradually becomes disordered and belongs to the superparaelectric state at x = 0.12 near room temperature. Moreover, the thermal evolution of the lattice kinetic behaviors shows two crucial temperatures: the depolarization temperature Td and the temperature at the maximum dielectric permittivity Tm, which suggest the transitions from nonergodic relaxor ferroelectric—ergodic relaxor (ER) ferroelectric and ER ferroelectric—superparaelectric, respectively. It is noteworthy that the series of changes is closely related to the ordering degree of the B-site ion affected by the doping and the temperature. This work gives an insight into the connection among the phonon behavior, electronic transition, and lattice structure of BNST-x ceramics, which can further understand the phase transition mechanisms under the doping and thermal field. [ABSTRACT FROM AUTHOR]

This article was originally published online on 15 November 2023 missing an affiliation. All affiliations and identifiers are correct as they appear above. All online versions of this article were corrected on 20 November 2023.By Zhifei Wang; Shiguang Yan; Fei Cao; Zhichao Hong; Yuelong Xiong; Benxia Chen; Chenhong Xu and Genshui WangReported by Author; Author; Author; Author; Author; Author; Author; Author [Extracted from the article]

High polarization of ferroelectric materials has profound research significance and is the decisive factor in the application of energy storage, pyroelectricity, and explosive energy conversion. Herein, in force-electric conversion field, an ultrahigh remanent polarization (51.43 μC/cm2) and record-breaking energy density (4.59 J/cm3) after poling were achieved with a lead-free (1 − x)Bi0.5Na0.5TiO3 − xAgNbO3 [(1 − x)BNT – xAN] relaxor ceramics. The enhancement effect of AgNbO3 on polarization is attributed to the increase in lattice distortion and orientation after poling. Additionally, a significant force-electric conversion effect under hydrostatic pressure (depolarization rate ∼44.8%, 400 MPa) and shock pressure (depolarization rate ∼54.4%, 6.3 GPa) in (1 − x)BNT – xAN was attributed to the pressure-driven ferroelectric/relaxor (FE/RE) phase transition. This work is expected to enlighten the further design of ferroelectric materials with high polarization for pulse power energy conversion application. [ABSTRACT FROM AUTHOR]

Compared to the bulky ceramic counterparts, antiferroelectric (AFE) thin films exhibit higher energy-storage performance. It has been demonstrated that the performance of the AFE thin films is strongly affected by the thickness. However, possible changes in the phase structures and microstructures accompanied by varying thicknesses have been less known, which makes it hard to fully understand the physical insight of the thickness effect. Herein, we fabricate a series of PbZrO3 (PZ) thin films by chemical solution deposition whose thickness is approximately proportional to the number of deposition layers, i.e., one to four layers with each layer of about 60 nm in thickness. The detailed structural characterization has been performed by using x-ray diffraction, a scanning electron microscope, and a transmission electron microscope. The films are composed of nanorods oriented normal to the films in which each nanorod maintains single crystalline though segmented by the horizontal interfaces between each of the two neighboring layers, suggesting nearly perfect epitaxy during multilayer growth. The multidomain state is found in three-/four-layer PZ thin films while the one-/two-layer PZ films always present a monodomain state. Meanwhile, incommensurate phases with different modulation periods have been observed in the four-layer PZ films. By comparing the as-observed structural features with the measured electrical properties of different films, it seems that microstructural evolution with the film thickness should not be negligible in evaluating the structure–property relation of PZ-based thin films. [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]

Practical pyroelectric materials require excellent pyroelectric performance, high depolarization temperature, and good temperature stability. In this work, the microstructure, ferroelectric, dielectric, and pyroelectric properties were studied systematically in (Bi0.5Na0.5)TiO3–0.1%MnCO3 (BNT–Mn) lead-free ceramics. It is observed that the pyroelectric coefficient p reaches 2.90 × 10−4 C m−2 K−1 at room temperature in the samples. Due to the low dielectric constant (291) and dielectric loss (0.010), the figures of merit (FoMs) Fi, Fv, and FD are as high as 1.03 × 10−10 m/V, 4.05 × 10−2 m2/C, and 1.86 × 10−5 Pa−1/2, measured at 1 kHz. With the increase in temperature, the p and FoMs change slightly, showing good temperature stability. More importantly, a relatively high depolarization temperature of 205 °C is achieved, which should help deliver reliable operation in practice. In general, all performances reveal that BNT–Mn ceramics are expected to pave the way for uncooled infrared detector applications. [ABSTRACT FROM AUTHOR]

As one of the classic antiferroelectrics, high complexity of a NaNbO3 structure sequence attracts great attention in the ferroelectric physics field. Here, temperature-pressure phase diagrams as a function of a CaSnO3 content for antiferroelectric (1-x)NaNbO3-xCaSnO3 ceramics have been improved by Raman spectroscopy. We clarify structural order of phase transitions on CaSnO3-modified NaNbO3 ceramics within the temperature range of 80–840 K by discussing the anomalies of lattice and phonon dynamics. The doping effect of CaSnO3 on the P-R phase transition has been summarized from the decreased critical temperature from 660 to 580 K. The intermediate phase at 480 K was recognized as an incommensurate phase. In addition, the anomalous pressure with respect to phonon frequency at the stress field of 0–25 GPa also provides the evidence of structural transformations at 6.55 and 10.05 GPa. Upon increasing the CaSnO3 content, phase transition moves to a lower pressure range. This work would provide the powerful supplement of phase transitions for the broad NaNbO3-based crystalline family with Raman scattering. [ABSTRACT FROM AUTHOR]

The scaling behaviors of dynamic hysteresis were investigated in serial rhombohedral Nb-doped Pb(Zr1-xTix)O3 (PZT) bulk ceramics as a function of frequency (f) and field amplitude (E0). Three distinct regions were plotted including linear loops, minor loops, and saturated loops with an increase of E0. When the external fields were over ∼1.5 times of coercive field (Ec), the scaling relations of saturated loops for these PZT ceramics could be expressed with an identical form as hysteresis area ∝ f 0.01E00.10, which indicated that similar ferroelectric systems with different compositions could display a uniform scaling law under high-E0 and low-f regions. [ABSTRACT FROM AUTHOR]

The temperature scaling of the ferroelectric hysteresis was first investigated in (K,Na)NbO3 films grown on SrRuO3/SrTiO3 over a temperature range from 100 K to 340 K. The power-law temperature scaling relations were obtained for , Pr, and Ec in the two distinguished temperature regions, separated by T ∼ 245 K. It was observed that and Pr had a similar temperature dependence, compared with Ec. With increasing T, and Pr decreased in the first region, and increased in the second region. While Ec decreased in the whole temperature range, but with different decrease rate in the two temperature regions. [ABSTRACT FROM AUTHOR]

In the practical application of capacitors, especially in pulsed application, recoverable energy is a key parameter, which represents the ability to store energy. However, many existing evaluation methods for energy storage calculation have not been systematically implemented and comprehensively understood. In this work, four methods were applied to calculate the energy storage in linear, ferroelectric, and antiferroelectric capacitors. All methods were valid when the linear capacitor was examined. In terms of the ferroelectric capacitor, the method of equivalent parameter using DC-bias capacitance was infeasible under the high voltage owing to a massive decrease in field-dependent capacitance. As for the antiferroelectric capacitor with noticeable hysteresis, the maximum of energy storage was obtained by the method of integration of hysteresis loop, while the lower one was obtained in the fast discharge condition by the method of integration of UI (product of voltage and current). In summary, for different materials, both test conditions and calculation methods should be considered to get accurate energy storage, which best fits the working conditions. [ABSTRACT FROM AUTHOR]

Utilizing temperature and magnetic field dependent dielectric spectroscopy, two different dielectric relaxation processes, both accompanied with prominent positive magnetodielectric (MD) effects, were observed in Pt/BiScO3-PbTiO3/La0.7Sr0.3MnO3 (Pt/BSPT/LSMO) heterostructure. An equivalent circuit model is established to quantitatively describe the relaxation data well. The simulation results elucidated that one relaxation process can be attributed to magnetic order associated BSPT/LSMO interfacial relaxation with abnormal dynamics feature. Another one is due to the external contact interface contributions. Both relaxation dynamics can be tuned, via magnetic field controlled localization of free interfacial charges, to induce MD effects in BSPT/LSMO interfaces and nonmagnetic Pt/BSPT contacts. [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]

The charge-discharge properties of lanthanum- and niobium-doped lead zirconate stannate titanate ceramics were investigated by directly measuring the hysteresis loops, dielectric constants under a dc bias field, and pulse discharge current-time curves after varying charge-discharge circulations. It was found that there was no significant effect of the charge-discharge circulation on these properties. The first pulse current peak reached 1.8 kA at 40 kV/cm, and most of the stored charge was released in 500 ns. These results show that the obtained slanted ceramics with high energy density can withstand hundreds of charge-discharge circulations and are very promising for pulse capacitor applications. [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]

Using spectroscopic ellipsometry, the optical properties of the Bi[sub 3.25]La[sub 0.75]Ti[sub 3]O[sub 12] (BLT) thin films with different film thicknesses on platinized silicon substrates prepared by chemical solution methods have been investigated in the 400-1700 nm wavelength range. By fitting the measured ellipsometric parameter (ψ and Δ) data with a multilayer model system and the classical dispersion relation for the BLT thin films, the optical constants and thicknesses of the thin films have been obtained. Meanwhile, some degree of inhomogeneity (in the form of low density layers or surface roughness) has been found in the BLT thin films except for the thinnest film, which was homogeneous throughout its thickness. The multilayer model system became very complicated with increasing thickness. It indicated that the microstructure of the BLT thin films varied with increasing thickness. The refractive index n of the BLT thin films increases with increasing thickness, and on the contrary, the extinction coefficient k decreases with increasing thickness. The dispersion of the refractive index can be well explained by a single-term Sellmeier relation. [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]

To support practical infrared detector applications, pyroelectric ceramics should exhibit excellent pyroelectric performances, high depolarization temperatures, and good thermal stabilities. In this study, the pyroelectric properties, depolarization behaviors, and thermal stabilities of tetragonal 0.8Bi0.5Na0.5TiO3–0.2BaTiO3 (0.8BNT–0.2BT) ceramics are studied systematically. The samples exhibit high depolarization temperatures (∼209 °C) and excellent thermal stabilities. More importantly, they display high pyroelectric coefficients (p = 2.42 × 10−8 C cm−2 K−1), as well as high voltage responsivity (Fv = 2.68 × 10−2 m2 C−1) and specific detectivity (Fd = 1.53 × 10−5 Pa−1/2) figures of merit at room temperature and 1 kHz. The overall properties of tetragonal 0.8BNT–0.2BT ceramics indicate their potential for application in infrared detectors. [ABSTRACT FROM AUTHOR]

Recently, dielectrics for energy storage have been attracting increasing attention due to their ultrahigh power density. However, the widespread application of dielectrics remains limited by their low energy density. In this work, lead-free single-phase relaxor (1 − x)Ba0.55Sr0.45TiO3-xBiMg2/3Nb1/3O3 [(1 − x)BST-xBMN] (x = 0, 0.05, 0.07, and 0.10) bulk ceramics were prepared by a conventional solid-state reaction process. The dielectric properties, the relaxor behavior, and the energy storage properties were explored in detail. With increasing BMN content, the observed increase in activation energy (Ea) and the decrease in freezing temperature (Tf) indicate that the coupling between polar nano-regions (PNRs) gradually weakened, leading to the decrease in remanent polarization (Pr) and the increase in energy storage efficiency (η). For the composition x = 0.07, the breakdown strength (BDS) significantly increased from 240 kV cm of pure BST to 450 kV cm. Finally, large Wrec (4.55 J cm3) and high η (81.8%) were achieved in 0.93BST-0.07BMN ceramics. The results demonstrate that the (1 − x)BST-xBMN ceramics have superior potential for use in advanced pulsed power capacitors. [ABSTRACT FROM AUTHOR]

Dielectric relaxation and magnetodielectric (MD) effects were observed in 0.36BiScO3-0.64PbTiO3/La0.7Sr0.3MnO3 thin films. The universal dielectric response and distribution of relaxation time modifications were introduced into the Maxwell-Wagner (MW) model. Based on modified MW model, the negative MD response at low frequencies was attributed to magnetostriction of La0.7Sr0.3MnO3, while the large positive response at high frequencies mainly to the magnetoresistance of La0.7Sr0.3MnO3, and these two factors canceled each other out at intermediate frequencies. Moreover, a giant room temperature MD response of 9.5% was observed, and the linear MD response at 52 kHz was ascribed to the linear magnetoresistance effects. [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 temperature scaling relations of the dynamic hysteresis were investigated in Zr-rich lead zirconate titanate (PZT) bulk ceramics. At each relation curve, there is a discontinuous district corresponding to the low- and high-temperature phase transitions. The temperatures are divided into low-T region and high-T region. At each temperature region, three power-law scaling relations were obtained for hysteresis area , coercivity Ec, and remnant polarization Pr with T, respectively. The six temperature scaling relations are field dependent and the simplified forms are different from the results obtained from the soft and hard PZT ceramics. [ABSTRACT FROM AUTHOR]

The pulsed power supply that generates megawatts of electrical power has drawn important attention for many decades. Despite that the large energy output has been obtained in lead-containing materials such as Pb(Zr0.95Ti0.05)O3 (PZT95/5) ceramics, lead-free ferroelectric candidates are highly desired due to the environmental concerns. In this work, we report the depolarization behavior of lead-free ternary 0.99[0.98(Bi0.5Na0.5)(Ti0.995Mn0.005)O3-0.02BiAlO3]-0.01NaNbO3 ferroelectric ceramics under shock wave compression. A current profile with a maximum value of ∼25 A and a FWHM of ∼2.3 μs was obtained. Particularly, the poled BNT-BA-0.01NN ceramics were almost completely depolarized under high strain rate loading, releasing a high charge density J of 38 μC/cm2. The released J was approximately 96% of thermal-induced charge density (∼40 μC/cm2), which was 18% higher than that of PZT95/5 ceramics. The shock-induced depolarization mechanism can be attributed to the ferroelectric-ergodic relaxor phase transition. These results reveal the BNT-based ceramics as promising candidates for pulsed power applications. [ABSTRACT FROM AUTHOR]

In this paper, the converse magnetoelectric (CME) effect by electric field tuning of magnetization in an original heterostructure composed of a polycrystalline yttrium iron garnet (YIG) film and a lead magnesium niobate-lead zirconate titanate (PMN-PZT) ceramic is presented. The magnetic performances of the YIG films with different thicknesses under a DC electric field applied to the PMN-PZT ceramics and a bias magnetic field are investigated. All the magnetization-electric field curves are found to be in good agreement with the butterfly like strain curve of the PMN-PZT ceramic. Both the sharp deformation of about 2.5‰ of PMN-PZT and the easy magnetization switching of YIG are proposed to be the reasons for the strongest CME interaction in the composite at the small electric coercive field of PMN-PZT (4.1 kV/cm) and the small magnetic coercive field of YIG (20 Oe) where the magnetic susceptibility reaches its maximum value. A remarkable CME coefficient of 3.1 × 10−7 s/m is obtained in the system with a 600 nm-thick YIG film. This heterostructure combining multiferroics and partially magnetized ferrite concepts is able to operate under a small or even in the absence of an external bias magnetic field and is more compact and power efficient than the traditional magnetoelectric devices. [ABSTRACT FROM AUTHOR]

The depolarization temperature Td determines the upper temperature limit for the application of piezoelectric materials. However, the origin of depolarization behavior for Bi-based materials still remains controversial and the mechanism is intricate for different (Bi0.5Na0.5)TiO3-based systems. In this work, the structure and depolarization behavior of (1-x)(Bi0.5Na0.5)TiO3-xBiAlO3 (BNT-BA, x = 0, 0.02, 0.04, 0.06, 0.07) ceramics were investigated using a combination of X-ray diffraction and electrical measurements. It was found that as temperature increased, the induced long-range ferroelectric phase irreversibly transformed to the relaxor phase as evidenced by the temperature-dependent ferroelectric and dielectric properties, which corresponded to a gradual structural change from the rhombohedral to the pseudocubic phase. Therefore, the thermal depolarization behavior of BNT-BA ceramics was proposed to be directly related to the rhombohedral–pseudocubic transition. Furthermore, Td (obtained from thermally stimulated depolarization currents curves) was higher than the induced ferroelectric-relaxor phase transition temperature TFR (measured from dielectric curves). The phenomenon was quite different from other reported BNT-based systems, which may suggest the formation of polar nanoregions (PNRs) within macrodomains prior to the detexturation of short-range ferroelectric domains with PNRs or nanodomains. [ABSTRACT FROM AUTHOR]

The current decay characteristic in the time domain is studied in Y3+ and Mn2+ modified Ba0.67Sr0.33TiO3 ceramics under different temperatures (25 °C-213 °C) and voltage stresses (0 V-800 V). The decay of the current is correlated with the overlapping of the relaxation process and leakage current. With respect to the inherent remarkable dielectric nonlinearity, a simple method through curve fitting is derived to differentiate these two currents. Two mechanisms of the relaxation process are proposed: a distribution of the potential barriers mode around room temperature and an electron injection mode at the elevated temperature of 110 °C. [ABSTRACT FROM AUTHOR]

This investigation presents a simple approach to realize the low temperature crystallization of Pb0.4Sr0.6TiO3 thin films at 400 °C by taking advantage of well controlled lead excess and kinetic-driving-force compensated thermodynamics crystalline via sputtering deposition. The thin films prepared at low temperature show fine-grained micro-structure because of the suppressed grain growth, furthermore, the intrinsic dielectric response can be modulated by the distinct level of crystallinity. The film processed at 450 °C exhibited a dielectric constant of 435 and high figure merit of 130 at 400 kV/cm, superior ferroelectric property, and stable performance with temperature and frequency. [ABSTRACT FROM AUTHOR]

The temperature scaling of dynamic hysteresis was investigated in Mn-doped Pb(Mn1/3Sb2/3)O3-Pb(Zr,Ti)O3 ceramic with internal bias field. A set of simple linear temperature scaling relations were established for hysteresis area , coercivity Ec, and internal bias field Ei, which are different from the power-law scaling relationships for the soft and hard PZT ceramics. The proposed scaling relation between and T can be predicted by the temperature dependent response of Ec and vice versa. It is suggested that the thermal deaging which related to the redistribution of the preferentially oriented defect dipoles is responsible for these dynamic hysteresis behaviors. [ABSTRACT FROM AUTHOR]

Polarization switching and energy storage properties of highly (100) oriented antiferroelectric (AFE) (Pb,La)(Zr,Ti)O3 thin films (≤250 nm) deposited via a sol-gel process with both LaNiO3 and Pt top electrodes were investigated. By using LaNiO3 top electrodes, the energy density as well as energy efficiency can be enhanced by 4.6 J/cm3 and 11%, respectively. Furthermore, the films with LaNiO3 top electrodes are more capable of providing high energy density over a wide temperature regime above room temperature compared to Pt. This work clearly highlights that oxide top electrodes can greatly improve the energy storage performance of antiferroelectric thin film capacitors. [ABSTRACT FROM AUTHOR]

Pyroelectric response mechanism of Ba0.70Sr0.30TiO3 ceramics under dielectric bolometer (DB) mode was investigated by dielectric and pyroelectric properties measurement. The variations of total, intrinsic, and induced pyroelectric coefficients (ptot, pint, pind) with temperatures and bias fields were analyzed. pint plays the dominant role to ptot through most of the temperature range and pind will be slightly higher than pint above T0. The essence of the enhancing effect of DC bias field on pyroelectric coefficient can be attributed to the high value of pint. This mechanism is useful for the pyroelectric materials (DB mode) applications. [ABSTRACT FROM AUTHOR]

Antiferroelectric Pb(Zr, Nb, Ti)O3 (PZNT) films were deposited via a sol-gel process on Pt(111)/Ti/SiO2/Si, LaNiO3- and La0.5Sr0.5CoO3-buffered Si substrate. The scaling behavior of the energy density W of antiferroelectric films was investigated. The scaling behavior of W against frequency f of PZNT on LaNiO3-buffered Si takes the form of W ∝ f0.08, which differs significantly from that form of W ∝ f-0.14 of PZNT on La0.5Sr0.5CoO3-buffered Si. This indicates that the scaling relations of W vary substantially as bottom electrodes change and might be closely related to the variation of nonuniform strain field and depolarization field within the AFE films. [ABSTRACT FROM AUTHOR]

The ferroelectric Ba0.6Sr0.4TiO3 (BST) and dielectric MgO composites with three different structures: columnar, layered, and spherical inclusion were prepared by spark plasma sintering (SPS). The microstructure and dielectric properties were investigated. Results show that the columnar composite exhibits an appreciable tunability (44.3%) as high as that of pure BST while the permittivity has been reduced from 5872 to 3998 at 10 kHz at room temperature, leading to a reduction of permittivity without deterioration of tunability in the bulk ceramics. This is a feasible way to balance the permittivity and the tunability, which is very promising for tunable devices application. [ABSTRACT FROM AUTHOR]

Pb0.7Sr0.3TiO3/La0.7Sr0.3MnO3 (PST/LSMO) thin film has been deposited on Si substrate by chemical solution deposition. Obvious changes in dielectric constant and loss as functions of frequency and magnetic field were observed in PST/LSMO thin film. By applying both dc bias electric and magnetic fields, apparent dielectric anomalies were observed in the 'butterfly-hysteresis' curves. These effects may be useful for practical application. The mechanism for the magnetocapacitance effects in PST/LSMO is rationalized by combining the Maxwell-Wagner capacitor model and the magnetoresistivity and magnetostriction of the LSMO. [ABSTRACT FROM AUTHOR]

Perovskite Ba0.6Sr0.4TiO3 (BST) thin films have been grown on Al2O3(0001) substrates without/with inserting an ultrathin TiOx seeding layer by rf magnetron sputtering. X-ray diffraction and pole figure studies reveal that the film with the TiOx layer (12-Å-thick) is highly oriented along the (111) direction and exhibits a good in-plane relationship of BST(111)∥Al2O3(0001). The high frequency dielectric measurements demonstrate that the complex permittivity ([variant_greek_epsilon]=[variant_greek_epsilon]′-j[variant_greek_epsilon]″) is well described by a Curie-von Scheidler dispersion with an exponent of 0.40. The resulting epitaxial BST films show high permittivity (∼428) and tunability (∼41%, at 300 kV/cm and 40 GHz) and their microwave properties (1-40 GHz) potentially could be made suitable for tunable devices. [ABSTRACT FROM AUTHOR]

A correction to the article "Magnetic field modulated dielectric relaxation behavior of Pt/BiScO3-PbTiO3/La0.7Sr0.3MnO3 heterostructure in metal-insulator transition region: An equivalent-circuit method" that was published online on January 19, 2012 is presented.

Both high pyroelectric properties and good temperature stability of ferroelectric materials are desirable when used for applications in infrared thermal detectors. In this work, we report lead-free ternary 0.97(0.99Bi0.5Na0.5TiO3-0.01BiAlO3)-0.03K0.5Na0.5NbO3 (BNT-BA-KNN) ceramics, which not only exhibits a large pyroelectric coefficient (p ∼ 3.7 × 10−8 C cm−2 K−1) and figures of merit (Fi, Fv, and Fd) but also shows excellent thermal stable properties. At room temperature, Fi, Fv, and Fd are determined as high as 1.32 × 10−10 m/V, 2.89 × 10−2 m2/C, and 1.15 × 10−5 Pa−1/2 at 1 kHz and 1.32 × 10−10 m/V, 2.70 × 10−2 m2/C, and 1.09 × 10−5 Pa−1/2 at 20 Hz, respectively. During the temperature range of RT to 85 °C, the achieved p, Fi, Fv, and Fd do not vary too much. The high depolarization temperature and the undispersed ferroelectric-ergodic relaxor phase transition with a sharp pyroelectric coefficient peak value of ∼400 × 10−8 C cm−2 K−1 are suggested to be responsible for this thermal stability, which ensures reliable actual operation. The results reveal the BNT-BA-KNN ceramics as promising lead-free candidates for infrared thermal detector applications. [ABSTRACT FROM AUTHOR]

Several 0.97PbZrO3–0.03Ba(Mg1/3Nb2/3)O3 (0.97PZ–0.03BMN) ceramics were prepared via the columbite precursor method. Their microstructures and pressure-dependent ferroelectric and depolarization performances were then studied. The X-ray diffraction patterns of ground and fresh samples indicate that a main rhombohedral symmetry crystal structure is present in the bulk and that it sits alongside a trace quantity of an orthorhombic antiferroelectric phase that results from the effect of grinding on the surface. The remanent polarization (Pr) of the 0.97PZ–0.03BMN reached 32.4 μC/cm2 at 4.5 kV/mm and ambient pressure. In an in situ pressure-induced current measurement, more than 91% of the retained Pr of the pre-poled sample was released when the pressure was increased from 194 MPa to 238 MPa. That this pressure-driven depolarization should be attributed to the pressure-induced ferroelectric–antiferroelectric phase transition is supported by the emergence of double P–E loops at high hydrostatic pressures. Moreover, the 0.97PZ-0.03BMN ceramics exhibit no temperature-induced phase transitions and little related polarization loss up to 125 °C, which suggests that Pr has excellent thermal stability. The sharp depolarization behavior at low pressures and excellent temperature stability reveal that our 0.97PZ–0.03BMN ceramics exhibit superior performances in mechanical–electrical energy conversion applications. [ABSTRACT FROM AUTHOR]

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]

Cax(Sr0.5Ba0.5)1-xNb2O6 [CSBN(x), x = 0.00, 0.10, 0.15, and 0.20] lead-Free ceramics were prepared by a traditional solid-state reaction technique. Dielectric, ferroelectric, and pyroelectric properties of CSBN(x) lead-Free ceramics were systematically investigated. The pyroelectric properties of CSBN(x) have been enhanced remarkably due to Ca addition and reached the maximum values at x = 0.15, with pyroelectric coefficient of 3.61 × 10-8 C/cm2 K and pyroelectric figure of merit of Fi = 172 pm/V, Fv = 0.021 m2/C, and Fd = 11.5 μPa-1/2, which are superior to other lead-free ferroelectric ceramics. These results indicate the potential of CSBN(x) ceramics for infrared detector applications. [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]