Journal of Physical Chemistry Letters
·
2020
·
IF 6.71
Lei Meng,Chen He,Wei Ji,Fei Yen
We observe sharp step-down discontinuities in the magnetic susceptibility of NH4H2PO4 and NH4H2PO4-d60 (60% deuterated) along the a- and c-axes occurring exactly at their antiferroelectric transition temperatures. For the case of KH2PO4, less pronounced discontinuities occur at the ferroelectric transition temperature. To explain this, we treat the acid protons as individual oscillators that generate current elements that translate to magnetic forces in near resonance with each other. With decreasing temperature, the resonant forces become more commensurate, which amplifies a disproportionate drop off of two types of magnetic forces to eventually trigger the structural phase transitions. For the case of NH4H2PO4, the associated internal magnetic field appears to aid the NH4+ to order at a higher temperature. At 49 K, a shoulder-like anomaly in both NH4H2PO4 and KH2PO4 is attributed to a possible onset of macroscopic quantum tunneling of protons. Our findings bring forth a new category of intrinsic multiferroic systems.
研究领域:
凝聚态物理
·
材料科学
·
固态物理
·
磁学
·
铁电学
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DOI
高影响因子
APPLIED PHYSICS LETTERS
·
2019
·Vol. 115
·期 5
·
IF 3.521
Wang Jinxin,Jiang Guicheng,Huang Weicheng,Liu Danqing,Yang Bin,Cao Wenwu
Materials with an electrocaloric effect (ECE) have been extensively studied for their cooling applications. Most ECE films are oriented and are difficult to integrate into industrial production processes. Here, an ECE ( ΔS = 4.48 J K −1 kg −1 and ΔT = 6.4 °C at ΔE = 390 kV cm −1 ) is obtained in an unoriented PbZr 0.95 Ti 0.05 O 3 (PZT) film fabricated on an FTO substrate using an improved sol-gel method. To improve the ECE, Si-doped PZT films with 1–4 mol. % of Si are deposited. X-ray diffraction and X-ray photoelectron spectroscopy results confirm that Si was doped into the PZT lattice. The orthorhombic and tetragonal antiferroelectric phases coexist in the PZT/0.01 Si film. A large ECE ( ΔS = 5.89 J K −1 kg −1 and ΔT = 8.5 °C at ΔE = 390 kV cm −1 ) is acquired in the PZT/0.01 Si film, which was measured by an indirect method. This work demonstrates that ECE of unoriented PZT antiferroelectric films on FTO substrates can be improved by a certain amount of Si doping.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Lingfang Zou,Zhuan Li,Zonglong Gao,Fu Chen,Wenjie Li,Yong Yu,Yimin Li,Peng Xiao
Improving the piezoelectric activity of lead zirconate titanate (PZT) ceramics is of great importance for practical applications. In this study, the influence of Pr 3+ doping on the ferroelectric phase composition, microstructure, and electric properties on the A-site of (Pb 1-1.5x Pr x )(Zr 0.52 Ti 0.48 )O 3 is extensively investigated. A dense and fine microstructural sample is obtained with the introduction of Pr 3+ . The results show that the morphotropic phase boundary (MPB) moves to the rhombohedral phase region. The rhombohedral and tetragonal phases exhibit an ideal coexistence in the 4 mol.% Pr 3+ doped (PPZT4) samples. Lead vacancy and the reduction of the potential energy barrier are considered to be the key mechanisms for donor doping, which is upheld by the Pr 3+ doping. Combining the I-E hysteresis loops with the P-E hysteresis loops, it becomes apparent that both contribution maximums of the domain switching and residual polarisation are in PPZT4. Moreover, the thermal aging resistance of PZT is improved by doping, and the temperature stability is optimised from 83% in PZT to 96% in PPZT4. Hence, an appropriate amount of Pr 3+ doping can effectively improve the piezoelectric activity of PZT ceramics in the MPB area and optimise the performance stability of the material under application temperatures.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 23
·12632-12642
·
IF 14.511
Liang Shu,Xin Zhang,Wei Li,Jing Gao,Hongliang Wang,Yu Huang,Yue-Yu-Shan Cheng,Qian Li,Lisha Liu,Jing-Feng Li
AgNbO3-based antiferroelectric films have attracted emerging attention in the field of dielectric energy storage and possess promising applications in photocatalysis and microwave devices. Unfortunately, it remains a challenge to fabricate pure-phase AgNbO3 films on Si substrates, precluding their further integration into electronic devices. Here, we, for the first time, report phase-pure AgNbO3 films on Pt/Ti/SiO2/Si substrates by a chemical solution deposition (CSD) method. A facile CSD route without using the hazardous pyridine additive is demonstrated to obtain a stable AgNbO3 precursor for spin-coating films. By comprehensively controlling the heat treatment conditions, secondary phases are eliminated in the deposited films. The phase transitions of the AgNbO3 films are also investigated, where intriguingly the room temperature phase is determined to be the antiferroelectric M2 phase, rather than the commonly reported M1 phase in bulk AgNbO3. Meanwhile, the relative dielectric permittivity surpasses 300 at room temperature and maintains at ∼400 with low dielectric loss (<0.05; measured at frequencies of 0.1–1 MHz) over a wide temperature range of 150–350 °C, within a 5% variation. This work provides an easy-to-implement process of AgNbO3 films which may attract scientific interests and potential applications.
研究领域:
材料科学
·
电子工程
·
能源存储
✓ 已验证
DOI
高影响因子
Nano Energy
·
2022
·
IF 19.069
Hongyu Li,Chris R. Bowen,Ya Yang
Pyroelectric materials are of interest for waste heat utilization and thermal detection. However, the low output current and inefficiency reduces their effectiveness. Here, we utilize the abrupt decrease in polarization of ferroelectric BaTiO 3 materials around Curie temperature to improve the output performance of a pyroelectric nanogenerator. The variation of the polarization leads to a large change in the density of surface free charges, resulting in an increase of pyroelectric current. We have designed a temperature control and recording system to realize direct measurement of the pyroelectric output current. The pyroelectric current, power and energy conversion efficiency of the device near the Curie temperature were measured to be 15.6-fold, 18-fold and 15.8-fold higher than those acquired near room temperature. Moreover, the temperature induced current and charge density enhancement can be applied to detect temperature and temperature change. The responsivity of the self-powered temperature sensor near T c is 120 nC/cm 2 ∙K, which 4.8 times higher than that near room temperature (25.1 nC/cm 2 ∙K). The results confirmed the ability to exploit a ferroelectric phase transition for pyroelectric performance enhancement.
研究领域:
材料科学
·
能源技术
·
传感器技术
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DOI
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
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 25
·1-8
·
IF 2.8
Hu Zhilong,Liu Hongbo,Tang Jian Guo,Lee Soo Wohn,Li Jun
NaNbO 3 (NN) has potential applications in energy storage devices due to its antiferroelectricity and environmentally friendly characteristics, but its low dielectric breakdown field strength ( E b ) and energy storage efficiency ( ƞ ) limit practical applications. In this study, the structure and electrical characteristics of NaNbO 3 were modulated by introducing Sr(Mg 1/3 Nb 2/3 )O 3 (SMN) to optimize its energy storage performance. The (1- x )NN- x SMN solid solution was synthesized using a classic solid-state reaction approach. According to X-ray diffraction analysis results, the prepared ceramics exhibit a pure phase when x is less than or equal to 0.15. With the increment of x , SMN disturbs the long-range polar order, induces pronounced relaxation ferroelectric phase (RFE) with reduced remnant polarization ( P r ), and enhances E b , leading to significant increases in recoverable energy storage density ( W rec ) and η . The optimized composition 0.875NN-0.125SMN has the best dielectric energy storage properties with a W rec of 1.28 J/cm 3 and an η of 88%.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 52
·期 1
·429-438
·
IF 5.6
Shuo Wang,Lida Tong,Xiaolong Zhang,Xiaoyan Zhang,Yaohang Gu,Xiwei Qi
Although high-power-density lead-free ceramic-based dielectric capacitors are considered promising candidates for energy storage applications, achieving a high recoverable energy density ( W rec > 5 J cm −3 ) typically requires the application of an external electric field ( E > 400 kV cm −1 ), which poses significant risks to the electrical insulation system. Therefore, the development of lead-free dielectric ceramics that exhibit high energy storage performance under moderate electric fields (300 < E < 500 kV cm −1 ) has become a critical research focus. In this study, a ferroelectric - antiferroelectric binary solid solution was constructed by incorporating the antiferroelectric material NaNbO 3 into Bi 0.2 Na 0.4 Ba 0.2 La 0.2 TiO 3 ceramics. Experimental results demonstrate that the incorporation of the antiferroelectric phase effectively reduces grain size, widens the band gap, and significantly enhances the relaxation behavior, thereby enabling a high maximum polarization ( P max ) and a low remnant polarization ( P r ) under moderate electric fields. Consequently, the 0.95Bi 0.2 Na 0.4 Ba 0.2 La 0.2 TiO 3 -0.05NaNbO 3 ceramic achieved an ultra-high W rec of 6.42 J cm −3 and an excellent energy storage efficiency of 89.4 % under a moderate electric field of 400 kV cm −1 , along with outstanding thermal and frequency stability. This work presents a promising strategy for developing dielectric materials with superior energy storage performance under moderate electric fields, aligning well with the requirements of advanced energy storage technologies.
研究领域:
材料科学
·
功能陶瓷
·
电介质物理
·
能源存储
·
固态化学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2024
·Vol. 37
·期 4
·2409887
·
IF 27.4
Zhefeng Lou,Yingjie Zhao,Zhihao Gong,Ziye Zhu,Mengqi Wu,Tao Wang,Jialu Wang,Haoyu Qi,Huakun Zuo,Zhuokai Xu,Jichuang Shen,Zhiwei Wang,Lan Li,Shuigang Xu,Wei Kong,Wenbin Li,Xiaorui Zheng,Hua Wang,Xiao Lin
2D materials with remarkable second-harmonic generation (SHG) hold promise for future on-chip nonlinear optics. Relevant materials with both giant SHG response and environmental stability are long-sought targets. Here, the enormous SHG from the phase engineering of a high-performance semiconductor, Bi 2 O 2 Se (BOS), under uniaxial strain, is demonstrated. SHG signals captured in strained 20 nm-BOS films exceed those of NbOI 2 and NbOCl 2 of similar thickness by a factor of 10, and are four orders of magnitude higher than monolayer-MoS 2 , resulting in a significant second-order nonlinear susceptibility on the order of 1 nm V −1 . Intriguingly, the strain enables continuous adjustment of the ferroelectric phase transition across room temperature. An exceptionally large tunability of SHG, approximately six orders of magnitude, is achieved through strain modulation. This colossal SHG, originating from the geometric phase of Bloch wave functions and coupled with sensitive strain tunability in this air-stable 2D semiconductor, opens new possibilities for designing chip-scale, switchable nonlinear optical devices.
研究领域:
材料科学
·
非线性光学
·
凝聚态物理
·
纳米光子学
·
半导体器件
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）