CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Feng Luo,Zhimin Li,Jiyuan Chen,Yuanshui Liu,Linzhuang Xing,Yangxi Yan,Yue Hao
Ecologically sustainable hard type piezoelectric ceramics are highly demanded for high power transducer applications in replacing lead-based piezoelectric ceramics. In this study, MnO was proposed as acceptor dopant to modify the electric properties of 0.75BiFeO 3 -0.25BaTiO 3 piezoelectric ceramics. Results showed that MnO doping reduced the lattice distortion of rhombohedral phase and facilitated the formation of pseudo cubic phase of 0.75BiFeO 3 -0.25BaTiO 3 system. Moreover, it caused the diversity of domain morphology and reduced the domain size as well. XPS analysis indicated that Mn 2+ ions suppressed the transition from Fe 3+ ions to Fe 2+ ions and gave rise to the increase of oxygen vacancies . Accordingly, the introduction of MnO synergistically increases the d 33 , K p , and Q m and lowers the tan δ of 0.75BiFeO 3 -0.25BaTiO 3 ceramics. The abnormal enhancement in hard type properties is ascribed mainly to the increase of extrinsic contribution rather than the pinning effect arising from oxygen vacancies. Finally, based on an optimal 0.75Bi(Fe 0.985 Mn 0.015 )O 3 -0.25BaTiO 3 system, an atomizer prototype was fabricated. The remarkable atomization effect suggests a competitive potential of 0.75BF-0.25BT ceramic for transducer application.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2023
·
IF 10.9
Mingxin Zhang,Cuiying Pei,Qi Wang,Yi Zhao,Changhua Li,Weizheng Cao,Shihao Zhu,Juefei Wu,Yanpeng Qi
Recently, the discovery of superconductivity with a critical temperature T c up to 80 K in Ruddlesden–Popper phases La n +1 Ni n O 3 n +1 ( n = 2) under pressure has garnered considerable attention. Up to now, the superconductivity was only observed in La 3 Ni 2 O 7 single crystal grown with the optical-image floating zone furnace under oxygen pressure. It remains to be understood the effect of chemical doping on superconducting La 3 Ni 2 O 7 as well as other Ruddlesden–Popper phases. Here, we systematically investigate the effect of external pressure and chemical doping on polycrystalline Ruddlesden–Popper phases. Our results demonstrate that the application of pressure and doping effectively tunes the transport properties of Ruddlesden–Popper phases. We find pressure-induced superconductivity up to 86 K in La 3 Ni 2 O 7 polycrystalline sample, while no signatures of superconductivity are observed in La 2 NiO 4 and La 4 Ni 3 O 10 polycrystalline samples under high pressure up to 50 GPa. Our study sheds light on the exploration of high- T c superconductivity in nickelates.
研究领域:
凝聚态物理
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Boyan Fu,Leyao Bi,Jiahui Lin,Jiaxing Fu,Junsheng Wen,Binglin Zou,Chunjie Wang,Yue Wang
ABO 3 -type gas sensors for ethanol gas-sensing remain a significant challenge. In this paper, porous microspheres of La 0.9 Fe 1-x Co x O 3 (x = 0, 0.05, 0.1, 0.15, 0.2) were synthesized via a ultrasonic-assisted hydrothermal method. The materials were characterized with various techniques to determine their phase structures, morphologies, electrochemical properties, and sensing abilities. For all investigated sensors, La 0.9 Fe 0.85 Co 0.15 O 3 exhibited a response value of 50.445 for 100 ppm ethanol gas at 200 °C (RH = 35 %), which is over eight times higher than that of LaFeO 3 under the same conditions. In addition to its high response to ethanol, La 0.9 Fe 0.85 Co 0.15 O 3 has excellent selectivity, humidity resistance (35–95 % RH), and a fast response/recovery time (18/9 s). Further analyses demonstrate that the synergistic effect of A-site cation defects and Co-doping plays a pivotal role in enhancing sensing performance by effectively increasing oxygen vacancy content and adsorption energy. This work presents an effective approach for developing high-performance ethanol gas sensors based on LaFeO 3 .
研究领域:
材料科学
·
化学传感
·
纳米技术
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Chenlong Liu,Dong Chen,Jangam Ashok,Plaifa Hongmanorom,Wenju Wang,Tianle Li,Zhigang Wang,Sibudjing Kawi
Chemical looping steam reforming of bio-oil is novel conversion technology utilizing waste energy, which is an advantage to reduce cost and improve environmental. However, complex reaction process between oxygen carrier and bio-oil constrain its development. In this study, perovskite based La 0.8 M 0.2 Ni 0.8 Fe 0.2 O 3 (M = Ca, Ce and Zr) were investigated as an oxygen carrier for chemical looping steam reforming of bio-oil model reaction. The perovskites were prepared via sol-gel method and the effect of doping for reforming of acetic acid as bio-oil model compound is also investigated. Among all the perovskite tested, Ce doped La 0.8 Ce 0.2 Ni 0.8 Fe 0.2 O 3 oxygen carrier gave superior and stable catalytic performance for 1440 min at 600 °C and steam/carbon mole ratio (S/C = 2). The fresh and spent oxygen carriers were characterized using XRD , H 2 -TPR, CO 2 -TPD, TG-DTG, Dielectric constant , Raman, XPS and XANES . Doping with base metal generally, improved coke resistance ability of the perovskite. CO 2 -TPD and XPS analysis reveal that the highest carbon resistance for La 0.8 Ce 0.2 Ni 0.8 Fe 0.2 O 3 perovskite is due to enhanced stronger surface basicity and oxygen adsorption. From DFT simulation and Dielectric constant results, the better activity for La 0.8 Ce 0.2 Ni 0.8 Fe 0.2 O 3 is attributed to its adsorption ability of reactants, oxygen and electron transfer from sub-surface to surface of the perovskite.
研究领域:
能源科学
·
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Zhao Changxing,Chen Liang,Yu Junxi,Zhu Qingfeng,Xian Zhenhui,Zeng Yang,Shan Dongliang,Shuhong Xie
The high-quality (0.78-x)BiTi0.1Fe0.8Mg0.1O3-0.22CaTiO3-(x)Na0.5Bi0.5TiO3 nanoscale-thick thin films were prepared successfully on the Pt/Ti/SiO2/Si substrate via the sol–gel method. The influence of Na0.5Bi0.5TiO3 doping on the structure, topography, piezoelectricity, ferroelectricity, and dielectricity of BTFM-CTO-NBT thin films was investigated systematically. The X-ray diffraction and Raman results manifested that NBT doping induced the formation of the tetragonal phase, which existed between the rhombohedral and orthorhombic phases, and the elemental mappings revealed that the distribution of each element was uniform simultaneously. X-ray photoelectron spectroscopy analysis showed that NBT doping could effectively restrain the reduction of Fe3+, thereby reducing the oxygen vacancy concentration. The film had a minimum leakage current of about 3.19 × 10–10 A/cm2, a higher piezoelectric response, a maximum remnant polarization (2Pr = 174.64 μC/cm2), and a relatively smaller coercive field (Ec = 359.90 kV/cm) as x = 0.05. At the same time, the corresponding film had a maximum dielectric constant (469.6) and a minimum dielectric loss (0.063) at 1 kHz. These insights offer an alternative pathway to enhance the properties of BTFM-CTO thin films.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2024
·Vol. 21
·期 3
·1688-1699
·
IF 1.8
Xiangtai Guo,Yu Sun,Liangliang Liu,Zilong Yu,Juan Liu
BiFeO 3 -BaTiO 3 -based ceramics are promising multiferroic materials for a wide range of applications. In this paper, the effects of different ionic valence state((Ga 0.5 Ta 0.5 ) 4+ , Ta 5+ ) doping on the structure and properties of 0.73BiFeO 3 -0.27BaTi 1- y (Ga 1- x Ta x ) y O 3 ceramics were investigated. X-ray diffraction analysis showed that all samples were determined by rhombohedral R3c phase and tetragonal P4mm phase. A frequency-independent dielectric anomaly with obvious thermal hysteresis was detected in all samples, indicating the first-order ferroelectric phase transition, and the Curie temperatures were all above 600°C. The ferroelectric analysis found that the doping of donor element Ta reduced the coercive field, with a slight decrease of remanent polarization, which can be attributed to the soft effect of Ta element. Meanwhile, the magnetic properties were enhanced for all samples, with a maximum in 15T ( x = 1, y = .015) sample, where M r = .13 emu/g. According to relevant analysis, high-valence element substitution can enhance the magnetic properties and reduce the coercive field of BiFeO 3 , while low-valence element substitution can reduce dielectric loss. This result points out a way for us to choose appropriate doping elements to improve the performance of BiFeO 3 ceramics.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2022
·Vol. 46
·期 7
·9733-9747
·
IF 4.672
Yingwei Xiong,Jinglan Wang,Min Jin,Xiaohong Wang
Summary Fe 2 O 3 is recognized as a promising oxygen carrier, but the susceptibility to sintering over the redox cycles limits its application. Although depositing Fe 2 O 3 on CeO 2 can simultaneously improve the activity and durability, the formation of CeFeO 3 will decrease the oxygen capacity and thus the efficiency of chemical looping water-gas shift reaction. Doping foreign elements can effectively mitigate the reaction between Fe 2 O 3 and CeO 2 and improve redox reactivity. This work employs Gd 3+ and Sm 3+ as doping elements and investigates the doping effect on hydrogen generation of Fe 2 O 3 /CeO 2 in water-gas shift with chemical looping. The characterizations demonstrate that both Gd and Sm are incorporated into the lattice of CeO 2 and increase the oxygen defect concentration, which boosts the redox reactivities. In addition, the interaction between the dopants and CeO 2 promotes the reduction depth by suppressing the solid reaction between Fe 2 O 3 and CeO 2 and improves the reoxidation reaction between reduced oxygen carriers with steam. As a result, Fe 2 O 3 /Ce 0.8 Sm 0.1 Gd 0.1 O 1.9 shows a high hydrogen yield (8.73 mmol.g −1 ) and hydrogen production rate (582.2 μmol.g −1 .min −1 ), which is 1.67 times higher than that of Fe 2 O 3 /CeO 2 . The performance remains stable over 40 cycles. The introduction of foreign cations may provide an effective method and significantly impact the oxygen carrier design.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Xue Zhang,Guoshuai Li,Feng Mao,Dongdong Han,Chengbin Jing,Ye Chen,Pingxiong Yang,Junhao Chu,Fangyu Yue
Doping- and temperature-induced phase transitions and optical/electric-properties for (1- x )KNbO 3 - x (Ba 0.5 Bi 0.5 )(Nb 0.5 Zn 0.5 )O 3 ceramics are studied. With the increase of x -value, a series of structural phase transitions from orthorhombic to tetragonal and to cubic is observed, and the phase transition temperatures are also improved for forming a stable phase. The deteriorated ferroelectric property , which also suggests the doping-induced phase transition due to the enhancement of the crystal symmetry , can be tentatively interpreted from the optical evolution with doping. This doping can introduce or enhance the bandedge- or in-gap states but without influence upon the optical bandgap of KNbO 3 . These results help in understanding the control of the structure, optical and electrical properties in KNbO 3 -based ferroelectric oxides.
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 Research Express
·
2022
·Vol. 9
·期 1
·016302
·
IF 2.025
Meizhen Zhuo,Chun-e Huang,Changzhi Zhao,Jiongjiong Yin,Chunying Shen
ZnO linear resistance ceramics were synthesized from ZnO–Al2O3–MgO–TiO2–SiO2–Ta2O5 by a conventional ceramics method. Effects of Ta2O5 on the phase composition, microstructures, and electrical properties of ZnO linear resistive ceramics were investigated. The results show that doping with appropriate amount of Ta2O5 can refine the grains of the main crystalline phase ZnO and the secondary crystalline phase ZnAl2O4 in terms of microstructure, and also can reduce the grain boundary barrier and optimize the I–V characteristics in terms of electrical properties. In addition, the doping of Ta2O5 can improve the stability of the resistivity , and the impedance frequency indicates that the doping of Ta2O5 makes the sample suitable for high-frequency electric fields. The resistivity of the sample doped with 0.2 mol% Ta2O5 is 56.2 Ω·cm, and this sample has the best grain boundary barrier height, nonlinear coefficient and temperature coefficient of resistance of 0.054 eV, 1.04 and −3.48 × 10−3 °C−1, respectively.
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
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Yingxin Li,Wei Qian,Yinqun Hua,Yunxia Ye,Fengze Dai,Jie Cai
Thermal barrier coatings with excellent thermal performance and corrosion resistance are essential for improving the performance of aero-engines. In this paper, (Y 3-x Yb x )(Al 5-x Sc x )O 12 (x = 0, 0.1, 0.2, 0.3) thermal barrier coating materials were synthesized by a combination of sol-gel method and ball milling refinement method. The thermal properties of the (Y 3-x Yb x )(Al 5-x Sc x )O 12 ceramics were significantly improved by increasing Yb and Sc doping content. Among designed ceramics, (Y 2.8 Yb 0.2 )(Al 4.8 Sc 0.2 )O 12 (YS-YAG) showed the lowest thermal conductivity (1.58 Wm −1 K −1 , at 800 °C) and the highest thermal expansion coefficient (10.7 × 10 −6 K −1 , at 1000 °C). In addition, calcium-magnesium- aluminum -silicate (CMAS) corrosion resistance of YS-YAG was further investigated. It was observed that YS-YAG ceramic effectively prevented CMAS corrosion due to its chemical inertness to CMAS as well as its unique and complex structure. Due to the excellent thermal properties and CMAS corrosion resistance, YS-YAG is considered to be prospective material for thermal barrier coatings.
研究领域:
材料科学
·
航空工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2023
·
IF 13.1
Fei Wu,Mengyun Ling,Lei Zhang,Qiuyu Zhang,Baoliang Zhang
Herein, we propose a combination strategy to induce robust room-temperature electromagnetic coupling in non-magnetic MoS 2 semiconductor (2H–MoS 2 ). The introduction of ascorbic acid (AA) is intended to introduce sulfur vacancies ( sv ) in the process of 2H–MoS 2 nano-sheet shells coating on the surface of three-dimensional (3D) matrix. It promotes the transformation of local lattice (2H–MoS 2 ) into metal phase (1T-MoS 2 ). The transformed 1T-MoS 2 phase improves the conductivity ( σ ) of the composite by 1.48 times. Due to the Mo 4+ 4 d energy state within the bandgap, the exchange interaction between the sv and the Mo 4+ 4 d bandgap state produces a robust intrinsic electromagnetic response of more than 1.2 emu/g. Density functional theory (DFT) calculations are used to analyze the above results, and a novel electromagnetic-coupling-enhanced microwave absorption mechanism is proposed. The results indicates that microwave absorption performance can be effectively improved by the phase-incorporation effect. The minimum reflection loss (RL min ) reaches −53.1 dB (1.7 mm) and the adjustable effective absorption bandwidth (EAB) covers 14.5 GHz (3.5–18 GHz) at the various matching thicknesses. This work might shed light on a new possibility of manipulating electromagnetic interaction to promote microwave absorption.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 6
·5771-5779
·
IF 2.195
Liu Heng,Zheng Shuaizhi,Chen Qiang,Zeng Binjian,Jiang Jie,Peng Qiangxiang,Liao Min,Zhou Yichun
HfO 2 thin films with different praseodymium doping contents (Pr:HfO 2 ) were fabricated by chemical solution deposition (CSD) method at ambient conditions. The chemical bonding and the composition of Pr doped HfO 2 thin film were characterized by X-ray photoelectron spectroscopy (XPS), while the structural properties were investigated by glancing incidence X-ray diffraction (GIXRD) and high resolution transmission electron microscopy (HRTEM). It is found that the ferroelectric orthorhombic phase was induced in the HfO 2 based thin films by Pr doping. The combined results of P–E (polarization–electrical field) and C–V (capacitance–voltage) measurements demonstrated that the 5 mol% Pr doped HfO 2 film exhibited a distinct ferroelectricity, with a maximum remanent polarization ( P r ) of 6.9 µC/cm 2 and a coercive field ( E c ) of 1.2 MV/cm. Notably, the polarization did not show obvious degradation over 1 × 10 8 switching cycles, suggesting good endurance performance of the Pr doped HfO 2 thin film. These results indicate that Pr dopant could effectively induce ferroelectricity in HfO 2 thin films, thereby becoming a new member of dopants for HfO 2 based ferroelectrics.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）