Journal of Materiomics
·
2020
·
IF 5.797
Gang Liu,Jia Dong,Leiyang Zhang,Yan Yan,Ruiyi Jing,Li Jin
In the present work, the nature of phase evolution of (1− x )(Na 0.5 Bi 0.5 )TiO 3 - x SrTiO 3 (NBT- x ST) solid solutions with x of 0–0.6 is revealed by characterizing the dielectric and ferroelectric properties. Two unique dielectric anomalies associated with high-temperature nanoregions (PNRs) in the ergodic relaxor (ER) state and low-temperature PNRs in the nonergodic relaxor (NR) state are identified. Characteristic temperatures, including T B , T RT∗ , T m , T d and T T ∗ , are determined in fresh and poled states on the basis of the characteristics of the evolution of these two dielectric anomalies. The whole evolution of the transition from the NR state to the ER state is reflected by the temperature-dependent polarization versus electric field ( P - E ) hysteresis loops, i.e., from the square loops, via the double-like loops, to the slim loops. The characteristic temperatures, including T P-N , T N-R and T R-dis , are determined by the characteristics of the evolution of P - E loops. Accordingly, a phase diagram of NBT- x ST was constructed according to these characteristic temperatures. Most importantly, the relationship between polarization responses and heterogeneous polar phase coexistence has been established and a schematic diagram is given. This work will help to understand the phase evolution and its impact on the macroscopic properties of NBT and the associated NBT-based solid solutions.
研究领域:
材料科学
·
物理学
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产品关联
DOI
高影响因子
Journal of Materiomics
·
2021
·
IF 6.425
Yang Yin,Jing-Ru Yu,Yu-Cheng Tang,Ai-Zhen Song,Huan Liu,Dong Yang,Jing-Feng Li,Lei Zhao,Bo-Ping Zhang
NaNbO 3 -based ceramics usually show ferroelectric-like P-E loops at room temperature due to the irreversible transformation of the antiferroelectric orthorhombic phase to ferroelectric orthorhombic phase, which is not conducive to energy storage applications. Our previous work found that incorporating CaHfO 3 into NaNbO 3 can stabilize its antiferroelectric phase by reducing the tolerance factor ( t ), as indicated by the appearance of characteristic double P-E loops. Furthermore, a small amount of MnO 2 addition effectively regulate the phase structure and tolerance factor of 0.94NaNbO 3 -0.06CaHfO 3 (0.94NN-0.06CH), which can further improve the stability of antiferroelectricity. The XRD and XPS results reveal that the Mn ions preferentially replace A-sites and then B-sites as increasing MnO 2 . The antiferroelectric orthorhombic phase first increases and then decreases, while the t shows the reversed trend, thus an enhanced antiferroelectricity and the energy storage density W rec of 1.69 J/cm 3 at 240 kV/cm are obtained for 0.94NN-0.06CH-0.5%MnO 2 (in mass fraction). With the increase of Mn content to 1.0 % from 0.5 %, the efficiency increases to 81 % from 45 %, although the energy storage density decreases to 1.31 J/cm 3 due to both increased tolerance factor and non-polar phase.
研究领域:
材料科学
·
陶瓷
·
储能
·
电陶瓷
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-8
·
IF 4.259
Lu Biao,Li Peilian,Tang Zhenhua,Yao Yingbang,Gao Xingsen,Kleemann Wolfgang,Lu Sheng-Guo
Both relaxor ferroelectric and antiferroelectric materials can individually demonstrate large electrocaloric effects (ECE). However, in order to further enhance the ECE it is crucial to find a material system, which can exhibit simultaneously both relaxor ferroelectric and antiferroelectric properties, or easily convert from one into another in terms of the compositional tailoring. Here we report on a system, in which the structure can readily change from antiferroelectric into relaxor ferroelectric and vice versa. To this end relaxor ferroelectric Pb 0.89 La 0.11 (Zr 0.7 Ti 0.3 ) 0.9725 O 3 and antiferroelectric Pb 0.93 La 0.07 (Zr 0.82 Ti 0.18 ) 0.9825 O 3 ceramics were designed near the antiferroelectric-ferroelectric phase boundary line in the La 2 O 3 -PbZrO 3 -PbTiO 3 phase diagram. Conventional solid state reaction processing was used to prepare the two compositions. The ECE properties were deduced from Maxwell relations and Landau-Ginzburg-Devonshire (LGD) phenomenological theory, respectively, and also directly controlled by a computer and measured by thermometry. Large electrocaloric efficiencies were obtained and comparable with the results calculated via the phenomenological theory. Results show great potential in achieving large cooling power as refrigerants.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Energy Storage Materials
·
2021
·
IF 17.789
Jie Jiang,Xiangjun Meng,Ling Li,Shun Guo,Ming Huang,Ji Zhang,Jing Wang,Xihong Hao,Heguo Zhu,Shan-Tao Zhang
Dielectric capacitors have drawn growing attention for their wide application in future high power and/or pulsed power electronic systems. However, the recoverable energy storage density ( W rec ) for dielectric ceramics is relatively low up to now, which largely restricts their actual application. Herein, the domain engineering is employed to construct relaxor antiferroelectric NaNbO 3 -BiFeO 3 bulk ceramics, which integrates the merits of antiferroelectrics and relaxors. It is revealed that the antiferroelectric phase transforms from orthorhombic P to R phase, and antiferroelectric domain evolves from micron-sized blocks to nanoscale clusters. Of particular importance is that the 0.90NaNbO 3 –0.10BiFeO 3 ceramic demonstrates ultrahigh W rec of 18.5 J cm −3 with giant electric breakdown strength of 99.5 kV mm −1 , which is superior than state-of-the-art bulk dielectric ceramics. Moreover, the 0.90NaNbO 3 –0.10BiFeO 3 ceramic exhibits superior frequency, cycling and thermal reliability, as well as the substantial current density (2140.6 A cm −2 ), ultrahigh power density (428.1 MW cm −3 ) and ultrafast discharge rate (14 ns). These results not only suggest that the NaNbO 3 -based relaxor antiferroelectric ceramics are promising candidates for advanced energy storage capacitors, but also provide feasible strategy of domain engineering to develop novel lead-free high-performance dielectric materials.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
Advanced Electronic Materials
·
2020
·Vol. 7
·期 1
·2000778
·
IF 6.593
Wei Jin,Mingsheng Xu,Xiaojie Zhou,Jiao Wang,Yichen Cai,Husnain Jawad,Mengge Yan,Bobo Tian,Qingmiao Nie,Bo Yan,Chunxiao Cong,Zhi-Jun Qiu,Ran Liu,Laigui Hu
Organic ferroelectrics, particularly the polymer polyvinylidene fluoride and its copolymer polyvinylidene fluoride-trifluoroethylene, have received much attention owing to their low cost, flexibility, and convenient thin film fabrication. However, development of this outstanding material for electronic applications is significantly impeded by its attributes of large coercive electric fields and poor spontaneous polarization. While the recent breakthroughs reveal that several kinds of molecular ferroelectrics (e.g., diisopropylammonium bromide (DIPAB)) can exhibit excellent properties comparable to inorganic ferroelectrics, it is still difficult to obtain high-quality continuous thin films for ferroelectric devices with high performance. In this work, a simple solution strategy is used for the preparation of large-area high crystallinity or even single-crystal DIPAB films. Subsequently, planar ferroelectric capacitors are developed with large in-plane ferroelectric polarization. These capacitors possess excellent memory function with small operating voltages (1–3 V), and a record remnant polarization of 13 µC cm −2 for organic ferroelectric devices. The findings have the potential to pave the way for the substitution of conventional ferroelectric polymers with DIPAB films for future organic ferroelectric devices.
研究领域:
材料科学
·
电子工程
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED PHYSICS
·
2016
·Vol. 119
·期 12
·
IF 2.101
Wei T.,Dong Z.,Zhao C. Z.,Guo Y. Y.,Zhou Q. J.,Li Z. P.
New unfilled tetragonal tungsten bronze (TTB) oxides, Ba 5−5x Sm 5x Ti 5x Nb 10−5x O 30 (BSTN-x), where 0.10 ≤ x ≤ 0.35, have been synthesized in this work. Their crystal structure was determined and analyzed based on Rietveld structural refinement. It is found that single TTB phase can be formed in a particular x range (i.e., 0.15 ≤ x ≤ 0.3) due to the competition interaction between tolerance factor and electronegativity difference. Furthermore, dielectric and ferroelectric results indicate that phase transitions and ferroelectric states are sensitive to x. Referring to the local chemistry, we suggest that the raise of vacancies at the A 2 -site compared with that of A 1 -site will intensely depress the normal ferroelectric phase and is in favor of relaxor ferroelectric state. Macroscopically, previous A-site size difference standpoint on fill TTB compounds cannot give a reasonable explanation about the variation of dielectric maximum temperature (T m ) for present BSTN-x compounds. Alternatively, tetragonality (c/a) is adopted which can well describe the variation of T m in whole x range. In addition, one by one correspondence between tetragonality and electrical features can be found, and the compositions involving high c/a are usually stabilized in normal ferroelectric phase. It is believed that c/a is a more appropriate parameter to illustrate the variation of ferroelectric properties for unfilled TTB system.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2021
·
IF 17.881
Jia-Han Zhang,Ying Zhang,Ningning Sun,Yong Li,Jinhua Du,Lipeng Zhu,Xihong Hao
The utilization of inorganic ferroelectric ceramics is thought to be an effective approach to enhance output performances of triboelectric nanogenerators (TENGs). However, the large remnant polarization from ferroelectric ceramics traps partial charges on electrodes all the time, which limits the performance improvement of TENGs and their applications in energy harvesting and self-powered sensing. Herein, achieving absolute exploitation of dielectric polarization from inorganic ceramics for significant performance enhancement is unprecedentedly proposed by using antiferroelectric ceramics with large polarization difference. The features of nearly zero remnant polarization and large maximum polarization for antiferroelectric ceramics perfectly match the working cycle mechanism of TENGs, enabling all polarization induced charges to flow through the external circuit. Based on this concept, an ideal flexible Pb 0.94 La 0.04 Zr 0.98 Ti 0.02 O 3 (PLZT) antiferroelectric ceramic inner-layer with record-high polarization difference is developed and assembled into a triboelectric nanogenerator (PLZT-TENG). The PLZT-TENG exhibits an outstanding output of 13.5 nC cm –2 , a 1.6-fold enhancement compared with the TENG with a PbZr 0.52 Ti 0.48 O 3 (PZT) ferroelectric ceramic inner-layer. Thanks to excellent flexibility, stability, and durability, the PLZT-TENG can serve as a biomechanical energy harvester and a self-powered sensor to be applied in practice. Our findings open a generic and upgradable way to the evolution and optimization of TENGs.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2022
·Vol. 24
·期 9
·2101770
·
IF 4.122
Jiaming Zhong,Hao Ju,Chao Fu,Xianghai Ran,Wei Nie
Flexible ferroelectric polymers are key candidates for flexible capacitive electronic devices. However, there is a lack of functional and accessible methods to control the ferroelectric response of polymers. Herein, a novel and effective approach is adopted to tune the ferroelectric response of polymers, over the conventional methods (graft or block copolymerization). Specifically, a central ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) layer is sandwiched between shielding layers (polymethacrylate (PMMA)). The differently distributed electric fields were generated in inner and outer layers owing to a larger polarization gradient between PMMA and P(VDF-TrFE), building a competition in the local ferroelectric layer. Controlling the polarization and thickness of the shielding layer may result in the electric field in it being lesser than the electric field in the ferroelectric layer during reverse poling, leading to a part of the dipoles reverting to the initial direction in the ferroelectric layer. Then dipoles along antiparallel directions coexist in P(VDF-TrFE), leading to antiferroelectric-like behavior. With the low remnant polarization, antiferroelectric-like films possess an excellent discharge energy density (11.72 J cm −3 at 3300 kV cm −1 ). Given the practicability and simplicity of tuning the ferroelectric response, it is firmly believed that this method will cut a conspicuous figure in a supercapacitor with ultrahigh energy density and discharged efficiency.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 17
·11432-11440
·
IF 3.9
Yang Hu,Huazhang Zhang,Jing Zhou,Jie Shen,Binbin Chen,Ang Li,Wen Chen
The ferroelectric behavior of Bi1/2(Na0.8K0.2)1/2TiO3 has been tailored by Eu3+ doping and the intermediate relaxor state is utilized for tristate ferroelectric memory effect. As Eu3+ content increases, the local structural disorder tends to get enhanced and the stability of ferroelectric order gets weakened. The disruption effect of Eu3+ is manifested structurally in XRD and PL spectra, and electrically in the ferroelectric, dielectric and piezoelectric properties. We found that the BNKT:3.0%Eu which owns a relaxor state under electrical cycle would be suitable for tristate ferroelectric memory, where two ferroelectric states and the relaxor state are respectively served as the “±1” and “0” memory states. We designed the verification experiments, and the results show good feasibility and stability. Moreover, it is innovative using PL spectra of Eu3+ to understand the structural changes related to different memory states, owning to its sensitivity to local structural symmetry. It also implies the possibility for non-destructive optical readout.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the American Chemical Society
·
2019
·
IF 14.695
Zhong-Xia Wang,Yi Zhang,Yuan-Yuan Tang,Peng-Fei Li,Ren-Gen Xiong
Antiperovskites have developed to be one kind of important functional material over the past few decades, showing abundant physical properties such as negative thermal expansion and superconductivity, etc. However, antiperovskite ferroelectrics have scarcely been discovered in inorganic ceramics. In this article, we report a new organic–inorganic hybrid antiperovskite ferroelectric [(CH3)2(F-CH2CH2)NH]3(CdCl3)(CdCl4) based on the strategy of molecular design. The replacement of one methyl in [(CH3)3NH]CdCl3 with ethyl produces the lower symmetric [(CH3)2(CH2CH3)NH]CdCl3 with nonpolar perovskite structure, while the polar hexagonal antiperovskite structure with the formula of X3BA (where X = [(CH3)2(F-CH2CH2)NH]+, B = [CdCl3]−, and A = [CdCl4]2–) was received after further fluoridation of the ethyl group. Therefore, fluoridation successfully achieves the structural transformation from perovskite to antiperovskite, as well as the significant changes in physical properties from nonferroelectric to ferroelectric. The antiperovskite [(CH3)2(F-CH2CH2)NH]3(CdCl3)(CdCl4) exhibits typical ferroelectric phase transition above room temperature (Tc = 333 K) including thermal anomalies, dielectric transitions, and second harmonic generation (SHG) responses. Moreover, lower coercive fields and easy polarization switching are observed by the measurements of hysteresis loops and ferroelectric domains. The saturated polarization (Ps) of 4.0 μC/cm2 is almost 10 times as large as those recently discovered antiperovskite molecular ferroelectrics. This finding provides a novel strategy to design and explore more antiperovskite organic–inorganic hybrid ferroelectric materials.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS LETTERS
·
2023
·Vol. 122
·期 24
·
IF 4
Gong Xin,Li Guannan,Lin Hua,Zhou Zengjie,Tang Jianfeng,Lu Yuming
BiFeO 3 -BaTiO 3 (BFO-BTO)-based lead-free electroceramics have long been synthesized using the microwave sintering approach, but the resulting multiferroic performance has not been excellent. In this work, we report an attempt to achieve competitive ferroelectric properties in microwave-sintered x BFO-(1– x )BTO ( x = 0.6–0.8) ceramics. Adopting a sintering process with a short dwell time of 30 min at 970 °C, we obtain high-quality ceramics with a high density, pure perovskite structure, uniform element distribution, and coarse grains. Furthermore, the fabricated ceramics can reproduce the typical characteristics of pure BFO-BTO, including a morphotropic phase boundary (MPB), relaxor ferroelectric behavior, weak ferromagnetism, and enhanced ferroelectricity near the MPB. More remarkably, a large intrinsic remnant polarization P r as high as ∼28 μ C/cm 2 is achieved by combing the MPB-enhanced ferroelectricity and the advantages of microwave synthesis. The maximal P r accomplished here is competitive with that of the same bulk solid solution obtained via other fabrication approaches. Our study illustrates that microwave synthesis is a powerful approach with which to prepare high-performance BFO-BTO-based ceramics.
研究领域:
材料科学
·
固态物理
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2018
·
IF 13.325
Cai Wei,Liu Kaihua,Gao Rongli,Deng Xiaoling,Chen Gang,Fu Chunlin
Bismuth ferrite (BiFeO 3 , short for BFO) is an important room-temperature single phase multiferroic materials. To further improve electric properties of BFO, La 3+ was introduced. Bi 1− x La
x
FeO 3 ( x = 0–0.12) thin films were fabricated by sol-gel method. The microstructure, optical and electric properties of Bi 1− x La
x
FeO 3 thin films have been investigated. XRD results show that Bi 1− x La
x
FeO 3 thin films is rhombohedral distortion perovskite structure and the addition of La 3+ can inhibit the formation of impure phase. The substitution of La 3+ for Bi 3+ on A sites can restrain the growth of grain and improve the roughness of thin films. The band gap of Bi 1− x La
x
FeO 3 thin films is less than that of BFO thin films, and its band gap decreases first and then increases as the content of La 3+ increases, which results from both Burstein-Moss effect and impurity level. A larger amount of La 3+ ( x = 0.12) can make leakage current of BFO thin films obviously decrease. Moreover, the remnant polarization and coercive electric field of Bi 1− x La
x
FeO 3 thin films increase with the increasing of La 3+ content. It results from the decrease of oxygen vacancy and effects of grain size. Keywords Bismuth ferrite Lanthanum Optical Dielectric Ferroelectric
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
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