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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]

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]

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]

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]

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]

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]

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]