CERAMICS INTERNATIONAL
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2022
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IF 5.532
Fenglong Zhang,Fei Ruan,Jinxiao Bao,Yang Li,Yuwei Ma,Rui Chen
In order to further understand the effect of Y 2 O 3 doping on the electrical conductivity of CaHf 1− x Y x O 3−δ , which was prepared by conventional solid-state reaction. The electrical conductivity of CaHf 1− x Y x O 3−δ was measured by two-terminal AC method in an oxygen-rich atmosphere, hydrogen-rich atmosphere and water vapor-rich atmosphere at the temperature between 973 and 1373 K. The test results show that the conductivity of CaHf 1− x Y x O 3−δ first increases and then decreases with x from 0.08 to 0.20, and its total conductivity and conductivity activation energy are 3.88 × 10 −7 to 5.34 × 10 −5 S/m and 0.76–0.92eV respectively. Combined with the test results of the H / D isotope effect, it is found that protons are the main conductive carriers in the three different atmosphere at temperatures range of 973–1173 K. In addition, in the temperatures range of 1273–1373 K, the positive holes are the main conductive carriers in the oxygen rich atmosphere, and the vacancies participates in the conductive process as the main conductive carriers in the water vapor rich atmosphere. The chemical diffusion coefficients of CaHf 1− x Y x O 3−δ is 3.9 × 10 −6 to 2.4 × 10 −5 cm 2 / s in the temperature range of 973–1373 K. According to the test results of electromotive force, the theoretical electromotive force is consistent with the measured electromotive force. The proton transfer number of CaHf 1− x Y x O 3−δ exceeded 97% in hydrogen atmosphere at temperatures from 973 to 1173 K. In sum, these findings of CaHf 1− x Y x O 3−δ can be used as alternative materials for hydrogen sensor electrolytes.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 9
·5261-5268
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IF 10.7
Jianwei Zhao,Hongtian Li,Yuxiao Du,Xiaoxin Chen,Hailan Qin,Jinming Wang,Tingnan Yan,Shuhui Yu,Yongming Hu,Dawei Wang
Lead-free ceramics have received considerable research interest because of their environmentally friendly characteristics and superb performance in energy storage applications, which are critical for pulsed power electronic systems. In this work, we sintered a series of (0.90 − x)BiFeO3–xBaTiO3–0.10CaHfO3 lead-free ceramics and comprehensively probed the crystallographic structure, grain morphology, electrical properties, etc., to assess their capability for use in energy storage applications. The 0.50BiFeO3–0.40BaTiO3–0.10CaHfO3 ceramic achieved an ultrahigh recoverable energy storage density of 4.70 J cm−3 and an outstanding energy conversion efficiency of 79% and can be considered an excellent material candidate for use in high-power energy storage devices.
研究领域:
材料科学
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电气工程
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能量存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
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IF 3.5
Xi Wu,Fei Ruan,Fenglong Zhang,Zhe Ren,Chonggui Lei,Yuwei Ma,Gaofei Pan,Weixiang Shang,Hongxia Li,Qingchun Wang,Jinxiao Bao
To study the electrochemical performance of aluminum doped CaHfO 3 proton conductors in more detail, the CaHf 1- x Al x O 3-δ ( x = 0.02,0.04,0.06,0.08) solid electrolytes were prepared by high-temperature solid-state method at the temperature of 1873K for 10 h. The XRD, SEM and EDS were used to test the phase structure and micro-morphology of the solid electrolytes, the Archimedes method was used to measure the density of the electrolytes, and the electrochemical workstation was used to test the performance of the electrolytes. The conductivity of the electrolytes in hydrogen, oxygen and water vapor atmospheres at 973–1373 K were measured by two-electrode AC impedance spectroscopy method, and the conductance activation energy of the electrolytes in different atmospheres were estimated based on Arrhenius' law. The H/D isotope effect of solid electrolytes were measured at 973–1273 K in H 2 and D 2 atmospheres, and the chemical diffusion coefficient and self-diffusion coefficient of hydrogen in the electrolytes were determined based on Fick's second law. The primary conducting carriers in different temperatures and atmospheres were revealed based on the conductivity test results. This study of aluminum-doped calcium hafnate electrolyte may provide reference for the research and development of calcium hafnate based proton conductors.
研究领域:
材料科学
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电化学
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固体物理
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能源材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materiomics
·
2023
·
IF 9.4
Jianwei Zhao,Hailan Qin,Xiaoxin Chen,Shuhui Yu,Dawei Wang
A number of CaHfO 3 modified BiFeO 3 -0.33BaTiO 3 (BF-0.33BT- x CH) lead-free piezoceramics were fabricated through the solid-state sintering method and comprehensively investigated in this work. Under the optimal sintering temperature, all compositions display a typical perovskite structure in a pseudo-cubic phase with slightly larger lattice parameters as the CH content increases. The electrical resistivity is highly enhanced due to the addition of CH. Microstructures, including the grain morphology, core-shell structure, and chemistry inhomogeneities, are demonstrated upon different BF-0.33BT- x CH compositions. In particular, the core-shell structures with non-uniform element distributions in the compositions can be eliminated by adding sufficient CH content ( x > 0.05). The highest saturation polarization (40.1 μC/cm 2 ), remnant polarization (26.8 μC/cm 2 ), and converse piezoelectric coefficient (290 pm/V) are achieved in the BF-0.33BT-0.01CH piezoceramic, which are significantly enhanced in comparison with the undoped BF-0.33BT piezoceramic. With further increasing the CH content, the piezoelectric properties of BF-0.33BT- x CH ceramics decline rapidly, and they start to exhibit characteristics of relaxor ferroelectrics.
研究领域:
材料科学
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陶瓷
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压电材料
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铁电材料
✓ 已验证
DOI
高影响因子
Journal of Materiomics
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2021
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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
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陶瓷
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储能
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电陶瓷
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2026
·Vol. 37
·期 5
·379
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IF 3.2
Zheng Kai,Xie Ning,Zhu Li-Feng,Jin Jiao,Liu Pengfei
(K, Na)NbO 3 (KNN) is regarded as a promising lead-free piezoelectric candidates due to its high Curie temperature and environmental compatibility. However, its piezoelectric performance remains inferior to Pb-based ceramics, mainly due to the rigid lattice and high coercive field that restrict domain switching. In this study, CaHfO 3 was introduced to modify the perovskite structure of KNN through a homologous co-doping mechanism. The simultaneous substitution of Ca 2+ and Hf 4+ modifies the local bonding environment and induces lattice softening, which effectively reduces the coercive field and facilitates polarization switching. At the optimal composition of 0.95(K 0.5 Na 0.5 )NbO 3 -0.02(Bi 0.5 Na 0.5 )ZrO 3 -0.03CaHfO 3 (0.95KNN-0.02BNZ-0.03CHO), the ceramics exhibit significant improvements in both ferroelectric and piezoelectric properties, while maintaining a balanced Curie temperature. This work provides clear evidence that structural softening induced by Ca-Hf incorporation provides an effective materials design strategy for enhancing the performance of lead-free KNN-based ceramics, while the compositional limits and long-term device-level behavior require further investigation.
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2026
·
IF 6
FengLong Zhang,YanYu Wang,WenYu Zhang,Fei Ruan,JinXiao Bao
This study investigates the electrochemical properties of two perovskite-type proton conductors, CaHf 0.82 Sc 0.18 O 2.91 (CHSc) and CaZr 0.82 Sc 0.18 O 2.91 (CZSc), synthesized via a high-temperature solid-state reaction method. The materials were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and AC impedance spectroscopy to evaluate their phase structure, morphology, and electrical conductivity. Both compositions formed dense, single-phase orthorhombic perovskite structures. The research systematically compares their performance, focusing on proton conductivity, chemical stability, and chemical diffusion coefficients. Key analyses, including the H/D isotope effect and electromotive force (EMF) measurements, were conducted to delineate the dominant charge carriers and optimal operating temperature ranges. Results demonstrate that both materials function as proton conductors below 1173 K, with proton transport numbers exceeding 0.90. Notably, the CHSc electrolyte exhibited superior overall electrochemical performance, including higher conductivity and chemical diffusion coefficient, compared to its zirconium-based counterpart. This enhanced performance is attributed to CHSc exhibiting higher chemical diffusion coefficient, proton transport number, and water hydration ability in the range of 873-1173 K. These findings underscore the potential of Sc-doped CaHfO 3 (CHO) as a promising electrolyte for intermediate-temperature electrochemical devices like hydrogen sensors and fuel cells.
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DOI
高影响因子
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