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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]

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]

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]

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 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]

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]