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© 2020, The Author(s). Benefitting from the reversible phase transition between antiferroelectric and ferroelectric states, antiferroelectric materials have recently received widespread attentions for energy storage applications. Antiferroelectric configuration with specific antiparallel dipoles has been used to establish antiferroelectric theories and understand its characteristic behaviors. Here, we report that the so-called antiferroelectric (Pb,La)(Zr,Sn,Ti)O3 system is actually ferrielectric in nature. We demonstrate different ferrielectric configurations, which consists of ferroelectric ordering segments with either magnitude or angle modulation of dipoles. The ferrielectric configurations are mainly contributed from the coupling between A-cations and O-anions, and their displacement behavior is dependent largely on the chemical doping. Of particular significance is that the width and net polarization of ferroelectric ordering segments can be tailored by composition, which is linearly related to the key electrical characteristics, including switching field, remanent polarization and dielectric constant. These findings provide opportunities for comprehending structure-property correlation, developing antiferroelectric/ferrielectric theories and designing novel ferroic materials.

© 2020, The Author(s). Benefitting from the reversible phase transition between antiferroelectric and ferroelectric states, antiferroelectric materials have recently received widespread attentions for energy storage applications. Antiferroelectric configuration with specific antiparallel dipoles has been used to establish antiferroelectric theories and understand its characteristic behaviors. Here, we report that the so-called antiferroelectric (Pb,La)(Zr,Sn,Ti)O3 system is actually ferrielectric in nature. We demonstrate different ferrielectric configurations, which consists of ferroelectric ordering segments with either magnitude or angle modulation of dipoles. The ferrielectric configurations are mainly contributed from the coupling between A-cations and O-anions, and their displacement behavior is dependent largely on the chemical doping. Of particular significance is that the width and net polarization of ferroelectric ordering segments can be tailored by composition, which is linearly related to the key electrical characteristics, including switching field, remanent polarization and dielectric constant. These findings provide opportunities for comprehending structure-property correlation, developing antiferroelectric/ferrielectric theories and designing novel ferroic materials.

© 2020, The Author(s). Benefitting from the reversible phase transition between antiferroelectric and ferroelectric states, antiferroelectric materials have recently received widespread attentions for energy storage applications. Antiferroelectric configuration with specific antiparallel dipoles has been used to establish antiferroelectric theories and understand its characteristic behaviors. Here, we report that the so-called antiferroelectric (Pb,La)(Zr,Sn,Ti)O3 system is actually ferrielectric in nature. We demonstrate different ferrielectric configurations, which consists of ferroelectric ordering segments with either magnitude or angle modulation of dipoles. The ferrielectric configurations are mainly contributed from the coupling between A-cations and O-anions, and their displacement behavior is dependent largely on the chemical doping. Of particular significance is that the width and net polarization of ferroelectric ordering segments can be tailored by composition, which is linearly related to the key electrical characteristics, including switching field, remanent polarization and dielectric constant. These findings provide opportunities for comprehending structure-property correlation, developing antiferroelectric/ferrielectric theories and designing novel ferroic materials.

© 2020, The Author(s). Benefitting from the reversible phase transition between antiferroelectric and ferroelectric states, antiferroelectric materials have recently received widespread attentions for energy storage applications. Antiferroelectric configuration with specific antiparallel dipoles has been used to establish antiferroelectric theories and understand its characteristic behaviors. Here, we report that the so-called antiferroelectric (Pb,La)(Zr,Sn,Ti)O3 system is actually ferrielectric in nature. We demonstrate different ferrielectric configurations, which consists of ferroelectric ordering segments with either magnitude or angle modulation of dipoles. The ferrielectric configurations are mainly contributed from the coupling between A-cations and O-anions, and their displacement behavior is dependent largely on the chemical doping. Of particular significance is that the width and net polarization of ferroelectric ordering segments can be tailored by composition, which is linearly related to the key electrical characteristics, including switching field, remanent polarization and dielectric constant. These findings provide opportunities for comprehending structure-property correlation, developing antiferroelectric/ferrielectric theories and designing novel ferroic materials.

Energy storage materials and their applications have long been areas of intense research interest for both the academic and industry communities. Dielectric capacitors using antiferroelectric materials are capable of displaying higher energy densities as well as higher power/charge release densities by comparison with their ferroelectric and linear dielectric counterparts and therefore have greater potential for practical energy storage applications. Over the past decade, extensive efforts have been devoted to the development of high performance, antiferroelectric, energy storage ceramics and much progress has been achieved. In this review, the current state-of-the-art as regards antiferroelectric ceramic systems, including PbZrO3-based, AgNbO3-based, and (Bi,Na)TiO3-based systems, are comprehensively summarized with regards to their energy storage performance. Strategies are then discussed for the further improvement of the energy storage properties of these antiferroelectric ceramic systems. This is followed by a review of the low temperature sintering techniques and the charge–discharge performance of antiferroelectric ceramics from a practical point of view. The review will be of benefit for researchers in the area as it offers a quick overview of recent progress in the development of various kinds of antiferroelectric ceramics and their properties. It should also stimulate the development of novel antiferroelectric ceramics with high energy storage performance.

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-2K-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 × 10-5Pa-1/2 at 1 kHz and 1.32 × 10-10 m/V, 2.70 × 10-2 m2/C, and 1.09 × 10-5Pa-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-2K-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.

Ferroelectricity in Langmuir-Blodgett (LB) films (Z-type and alternated Y-type) of nitrogencrown (NC) and arachidic acid (AA) was investigated by electric polarization measurements and small angle X-ray diffraction (SAXD). For Z-type AA LB multilayer and the AA LB films incorporating barium ions, as well as for Z-type NC LB multilayer and the Y-type NC/AA alternating LB films, hysteresis loops of the samples were observed and confirmed existence of the remnant polarizations in the LB films. Their corresponding remnant polarizations were found to be 15, 180, 450 and 9400 μC m-2, respectively. Therefore, the maximum ratios of remnant polarizations up to 620 (9400/15)-folds were obtained from NC/AA alternating LB films. The enhancement of ferroelectricity in NC/AA alternating LB films was observed for the first time. It was demonstrated that the enhancement of ferroelectricity in the LB films could be created by incorporation of barium ions into the LB film structures and strong interaction due to electron clouds redistribution largely originated from the compact insertion configuration of AA between two chains of NC molecules in interleaving films. © 2005 Elsevier B.V. All rights reserved.

Typical ferroelectricity in Langmuir-Blodgett multilayers prepared from hemicyanine dyes has been demonstrated by observed ferroelectric hysteresis loop. Their ferroelectric properties are found to be thickness dependent. The coercive field decreased with increasing film thickness monotonously and may be approximated by a power law Ec ∞ N-4/3 in the range from 30 to 200 nm, which is coincident with other conventional ferroelectric materials. The optimum thickness of hemicyanine LB multiplayer is about 60 nm and their optimum value as ferroelectric storage-devices has the same order of magnitude as P(VdF-TrEE) (n:n = 70:30).

Typical ferroelectricity in Langmuir-Blodgett multilayers prepared from hemicyanine dyes has been demonstrated by observed ferroelectric hysteresis loop. Their ferroelectric properties are found to be thickness dependent. The coercive field decreased with increasing film thickness monotonously and may be approximated by a power law Ec ∞ N-4/3 in the range from 30 to 200 nm, which is coincident with other conventional ferroelectric materials. The optimum thickness of hemicyanine LB multiplayer is about 60 nm and their optimum value as ferroelectric storage-devices has the same order of magnitude as P(VdF-TrEE) (n:n = 70:30).

Typical ferroelectricity in Langmuir-Blodgett multilayers prepared from hemicyanine dyes has been demonstrated by observed ferroelectric hysteresis loop. Their ferroelectric properties are found to be thickness dependent. The coercive field decreased with increasing film thickness monotonously and may be approximated by a power law Ec ∞ N-4/3 in the range from 30 to 200 nm, which is coincident with other conventional ferroelectric materials. The optimum thickness of hemicyanine LB multiplayer is about 60 nm and their optimum value as ferroelectric storage-devices has the same order of magnitude as P(VdF-TrEE) (n:n = 70:30).