PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2014
·Vol. 16
·期 26
·13078-13085
·
IF 4.198
Dan Xu,Lidong Wang,Weili Li,Wei Wang,Yafei Hou,Wenping Cao,Yu Feng,Weidong Fei
BaTiO3–xAlN (BT–xAlN) composite ceramics were prepared by conventional solid state reaction sintering. The effects of the AlN content on the crystalline structures, densities, and electrical and mechanical properties of the BT ceramics were investigated. The BT–1.5%AlN ceramic exhibits a good piezoelectric constant of 305 pC N−1 and an improved Vickers hardness of 5.9 GPa. The enhanced piezoelectricity originates from interactions between defect dipoles and spontaneous polarization inside the domains due to the occurrence of local symmetry, caused by the preferential distribution of the Al3+–N3− pairs vertical to the c axis. The hardening of the material is attributed to the improved density, and particle and grain boundary strengthening. Our work indicates that if a suitable doping ion pair is designed, lead-free ceramic systems prepared from ordinary raw materials by a conventional sintering method have a high probability of exhibiting good piezoelectric and mechanical properties simultaneously.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Jie Wu,Gaochao Zhao,Wei Dong,Chengbing Pan,Kun Tao,Wenjuan Huang,Peng Tong,Jie Yang,Xuebin Zhu,Lihua Yin,Wenhai Song,Yuping Sun
The effects of quenching on the structural, electrical, dielectric, ferroelectric (FE), and piezoelectric properties are investigated systematically in the 0.85BiFe1-xCrxO3-0.15BaTi1-xMnxO3 (0 ≤ x ≤ 0.03) ceramics. Optimal piezoelectricity and FE Curie temperature are obtained through optimized quenching rate and temperature. Quenching effect on piezoelectricity is especially significant for the samples near morphotropic phase boundaries (MPB), which can be ascribed to quenching-induced changes in phase ratio (rhombohedral and tetragonal phase) and domain structure/defect dipole orientation. Moreover, a new poling method, that is, cooling the sample at a constant dc current across FE TC, is established to improve the piezoelectricity. This work not only reveals the possible mechanism of quenching effect on the improved piezoelectricity in the BFO-based piezoceramics (especially near the MPB) but also suggests an electric current poling strategy for improving piezoelectricity by suppressing the defect dipole effects in BFO-based and even other piezoelectrics.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Jimin Lin,Jin Qian,Yunjing Shi,Simin Wang,Jinfeng Lin,Guanglong Ge,Yin Hua,Bo Shen,Jiwei Zhai
The impact of defects on the performance of piezoelectric materials has been a topic of considerable debate, due to the competing actions of the deteriorating effect of the defects themselves on the ceramic resistance and the positive effect on the piezoelectric performance resulting from the defect polarization. In order to probe its combined influence on piezoelectric properties, here, we designed BiFeO3 (BF)-based ceramics with different defect concentrations. It has been demonstrated that the incorporation of an appropriate concentration of defects into ceramics can effectively enhance their piezoelectric properties while maintaining their insulating properties. During the polarization process, both the intrinsic polarization and defect dipoles are oriented along the direction of the electric field. This occurs in the presence of a high temperature environment as well as an applied electric field, which results in a complementary enhancement of the macroscopic ferro- and piezoelectric properties. Consequently, the piezoelectric performance of BF–BT–BKT ceramics is achieved (d33 = 203 ± 5 pC/N, TC = 502 °C, kp = 33.05%). This work provides a framework for understanding the intrinsic structural mechanism of bismuth ferrate.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2024
·
IF 5.2
Jiaqi He,Jiao Han,Menghong Li,Mingwei Li,Ju Zhou,Ping Yang,Shiqi Li,Wenhan Qi,Zehui Lin,Gang Wang,Yiming Zeng,Li Chen
A series of Sr 1‒1.5 x Lu x TiO 3 ( x = 0, 0.005, 0.01, 0.015, and 0.02) ceramics was sintered under an air atmosphere through the solid-state reaction method. The results show that doping with Lu 3+ considerably enhances material permittivity. The ceramic with x = 0.01 exhibits a colossal permittivity (CP) of ∼101000 with a tan δ of ∼0.16 at a frequency of 1 kHz, demonstrating enhanced stability over a wide temperature (30 to 300 °C) and frequency (10 2 to 10 6 Hz) range. Based on the analysis of dielectric relaxation, X-ray photoelectron spectroscopy (XPS), and the universal dielectric response law, the CP effect is primarily due to the formation of defect dipoles, which are correlated with the presence of oxygen vacancies, such as Ti 3+ Ti 3+ , , Ti 3+ , and Ti 3+ . These defect dipoles serve to pin electrons, limiting long-range transitions, and enhancing local polarization. Doping with Lu 3+ also induces a secondary Lu 2 Ti 2 O 7 phase, which are characterized by X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The results generated in this study can inform the development and application of new CP materials based on SrTiO 3 .
研究领域:
材料科学
·
固态化学
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
·
2023
·Vol. 120
·期 12
·e2216627120
·
IF 11.1
Xiaolin Lu,Xujie Wang,Yong Liu,Tao Ding
Chiral nanostructures based on semiconductors exhibit pronounced properties of chiral luminescence and optoelectronic responses, which are fundamental for chiroptoelectronic devices. However, the state-of-the-art techniques of generating semiconductors with chiral configurations are poorly developed, most of which are complicated or of low yield, rendering low compatibility to the platform of optoelectronic devices. Here we show polarization-directed oriented growth of platinum oxide/sulfide nanoparticles based on optical dipole interactions and near-field–enhanced photochemical deposition. By rotating the polarization during the irradiation or employing vector beam, both three dimensional and planar chiral nanostructures can be obtained, which is extendable to cadmium sulfide. These chiral superstructures exhibit broadband optical activity with a g-factor of ~0.2 and a luminescence g-factor of ~0.5 in the visible, making them promising candidate for chiroptoelectronic devices.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Xingxing Zhou,Minghe Cao,Zhijian Wang,Yun Rao,Qu Luo,Bo Yang,Hua Hao,Zhonghua Yao,Zhiyong Yu,Hanxing Liu
Sr 0.99 Ce 0.01 Ti 1-x O 3 (SCT, x = 0, ± 0.0025, ± 0.0050, 0.0075) ceramics were prepared by solid state reaction methods and sintered in air atmosphere at different temperatures, with a soaking time of 2 h. The dielectric properties of all samples presented excellent temperature independence over a broad temperature range from 25 to 330 ℃ and frequency independence between 10 kHz and 1 MHz. Sr 0.99 Ce 0.01 Ti 0.9925 O 3 (SCT0.9925) ceramics sintered in air atmosphere exhibited a high permittivity (~5400) and a low dielectric loss (~0.01) measured at room temperature and 1 kHz. XPS and complex impedance spectroscopy analysis confirmed that the high permittivity and low dielectric loss were attributed to the fully ionized oxygen vacancies and giant defect-dipoles in Ti-deficient samples. However, a higher dielectric loss of Ti-rich samples is owing to the destruction of giant defect dipoles, in which highly localized electrons were transformed into hopping electrons.
研究领域:
材料科学
·
陶瓷工程
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 10
·1-8
·
IF 2.8
Liu Yingchun,Meng Xianghe,Shi Wenming,Deng Yuanhao,Zhang Hongjun
The high-temperature poling strategy (110 °C, 30 kV/cm, 20 min) was imposed on Cu-doped (Ba 0.94 Ca 0.06 )(Zr 0.05 Ti 0.95 )O 3 ceramics which had the Curie temperature of 117 °C, to enhance the piezoelectric performances. The high-temperature poled piezoelectric constants d 33 and electromechanical coupling factors k p were 410 pC/N and 0.516, which were enhanced by 17.1% and 15.4%, respectively, higher than that of traditional poled ones. Effects of high-temperature poling on the switching characteristic between non-180° and 180° domains were verified by the intensity ratio of splitting peaks at 2 θ around 45°, using the X-ray diffraction analysis. The high-temperature poled samples showed more asymmetric hysteresis loops, with higher internal bias field of 1.8 kV/cm, maximum polarization of 18.5 μC/cm 2 , and residual polarization of 10.7 μC/cm 2 , but lower coercive field of 2.5 kV/cm and smaller positive hysteresis of 1.3%. The high-field piezoelectric constant d 33 * showed a pronounced jump of 112.2 pm/V at 110 °C, confirming the optimal poling temperature. The stronger compensating defect dipole field mainly contributed to the asymmetry. And the tiny and easily reversible domains, observed by the in-situ piezoelectric force microscopy, were responsible to the improvement on piezoelectricity.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2024
·
IF 3.7
Tingyu Zhao,Ruirui Cui,Kaixin Guo,Min Zhang,Xu Wang,Jun Zhang,Chaoyong Deng
In this work, by doping the B-site of BaTiO 3 with Mg elements, we have prepared BaMg x Ti 1- x O 3- x (BM x T) films with superparaelectric behaviors. The microstructures, polarization behaviors, breakdown strength, leakage current density, and energy storage performance are investigated systematically of the BM x T films. The breakdown strength of the film reaches 7.5 MV/cm when x = 0.18, at the same time, excellent energy storage density (67.7 J/cm 3 ) and energy storage efficiency (94.9 %) are obtained, which is attributed to the doping of the acceptor element Mg. By doping Mg with a lower chemical valence state to form defect dipoles in the lattice, the breakdown strength and polarization properties of the film are improved while reducing the crystallinity of the film, forming a hysteresis loop with superparaelectric properties. This work provides a feasible route to design superparaelectric materials with simple compositions for high-performance capacitive energy-storage.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2021
·
IF 5.985
Haoran Xu,Guanghu He,Sheng Chen,Shaonan Chen,Rui Qiao,Hang Luo,Dou Zhang
Although polymer dielectrics show wide application prospects in electronic and electrical fields, a low relative dielectric constant and a low energy density restrict their rapid developments. To overcome these shortcomings, a strategy is proposed to facilitate orientational polarization through the incorporation of the π–π stacked biphenyl side groups in dipolar polymers. In this study, sulfonyl-containing poly(norbornene)s with and without biphenyl groups were synthesized by ring-opening metathesis polymerization, denoted as PBTMD-SO2 and PTMD-SO2, respectively. Their dielectric behaviors and energy-storage properties were investigated. The dielectric constant of PBTMD-SO2 with the biphenyl side groups was as high as 11.1 at 25 °C and 1 kHz, which was nearly 35% higher than that of PTMD-SO2 due to the stronger orientational polarization. In addition, the dielectric loss in the range of 1 kHz to 1 MHz increased from 0.061 to 0.172 for PTMD-SO2 and from 0.075 to 0.110 for PBTMD-SO2. Electric displacement–electric field loops studies indicated that the discharge energy density of PBTMD-SO2 reached 1.69 J/cm3 at 180 MV/m with a high efficiency of 87.1%, which exceeded the discharge energy density of 1.29 J/cm3 for PTMD-SO2 at 200 MV/m. This work offers a new idea for the design of high-performance dielectric polymers.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
POLYMER
·
2019
·
IF 3.771
Haibin Sun,Xueying Liu,Haichao Yan,Zhanbin Feng,Bing Yu,Nanying Ning,Ming Tian,Liqun Zhang
Grafting polar groups onto elastomer chains has proven to be an effective method to achieve high performance homogeneous dielectric elastomers (DE). Up to now, there still lacks an in-depth understanding of the effect of structure and content of these grafted dipoles on the electromechanical properties of the modified DE. In this study, three kinds of polar groups including carboxyl (COOH), hydroxyl (OH), and ester (COOCH 3 ) were grafted onto polymethylvinylsiloxane (PMVS) by using a photochemical thiol-ene reaction to prepare PMVS-COOH, PMVS-OH and PMVS-COOCH 3 DE. Three grafting degrees (15%, 50% and 95%) were prepared for each kind of modified PMVS. Interestingly, although the dipolar moment of COOH is higher than that of OH and COOCH 3 , at the same grafting degree, the dielectric constant of PMVS-OH is much higher than that of PMVS-COOCH 3 and PMVS-COOH. At high grafting degree (50% and 95%), the actuated strain at a specific electric field of PMVS-OH is significantly higher than that of PMVS-COOH and PMVS-COOCH 3 . The actuated train at 15 kV/mm sharply increases from 0.2% for PMVS to 9.1% for PMVS-OH with the grafting degree of 95%, higher than that of the commercial silicone DE and the new structured silicone DE reported previously. These dielectric, mechanical and actuated properties are affected by the combined effects of moment, mobility and interactions of these dipoles, which have been deeply discussed. The present study provides guidance for the preparation of high-performance homogeneous DE by rational designing the dipolar structure and content.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2024
·
IF 10.5
Ying Su,Bin Jiang,Haochen Shen,Na Yang,Xiaowei Tantai,Xiaoming Xiao,Yongli Sun,Luhong Zhang
Carbon materials have obtained some achievements in electromagnetic wave (EMW) absorption owing to their excellent electrical conductivity and low density. However, poor impedance matching and high electrical conductivity limit their EMW absorption properties. Metal single atoms absorbers have garnered considerable attention in EMW absorption, largely due to the high metal availability and special coordination structure, but the modulation of the EMW absorption properties still needs to be improved. Herein, atomically dispersed Fe sites embedded into the N-doped mesoporous carbon spheres (Fe–SAs/NC) were synthesized through a facile coordination-assisted polymerization assembly strategy without acid leaching treatment. Benefitting from abundant mesoporous structure, the Fe–SAs/NC displays large specific surface area (339 m 2 g −1 ) and optimized impedance matching, which results in an effective reduction of the absorber density. The homogeneously dispersed Fe single atoms (Fe–SAs) on the carbon skeleton lead to the improvement in conduction and dipole polarization losses of Fe–SAs/NC, which endows Fe–SAs/NC with exceptional EMW absorption properties. Experimental results indicate that Fe–SAs/NC displays desirable EMW absorption properties with the minimal reflection loss of −52.5 dB at 2.8 mm and the effective absorption bandwidth of 4.8 GHz. The study provides valuable insights for the development of carbon materials modified with atomically dispersed metal sites to achieve high-efficient EMW absorbers.
研究领域:
材料科学
·
电磁学
·
纳米技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yaxuan Chen,Shangxian Zhou,Jinsheng Li,Shuning Li,Huanyu Zhao,Mengwen Zhang,Pengfei Li,Xiwei Qi
In this study, La 2 (TiZrSnHfGe) 2 O 7 high entropy oxides were firstly prepared by solid state reaction method. The effects of different sintering temperatures on the structure, morphology and dielectric properties were studied. When the pre-calcination temperature is 1300 °C, the powder exhibits a single pyrochlore phase instead of defective fluorite phase. The existence of high entropy affects the changes in the crystal structure of A 2 B 2 O 7 type oxides, resulting in lattice distortion. The dielectric results showed that the ceramics have certain frequency dispersion, and the dielectric properties are affected by temperature and frequency. Due to the high entropy effect, the La 2 (TiZrSnHfGe) 2 O 7 ceramic exhibits good dielectric stability at both high and low frequencies. The formation of defect dipole clusters in the system results in the increase of dielectric constant. It is feasible to change the dielectric properties of ceramics by designing high entropy oxides, which showed the potential value in microelectronics field.
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
危险品化学品经营许可证（带存储）