JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·
IF 6.2
Hongwei Yang,Yong Ren,Fang Xu,Yulong Liao,Xiaoyu Li,Guixiang Liu,Bo Dai
Prior studies predominantly utilized solid-state sintering to fabricate Ni-based ferrite ceramics, aiming to enhance magnetic properties. While some researchers have adopted the hot-pressing method for preparing these ceramics, the resultant porosity remained elevated (>2 %), leading to an increased ferromagnetic resonance linewidth (Δ H ). The impact of high temperature and pressure during the forming process on Δ H and gyromagnetic properties in nickel-based ferrite ceramics has been seldom explored using hot pressing. Building on prior research involving solid-state sintering of Ni-based ferrite, this study employed a vacuum hot-pressing sintering technique to further optimize the gyromagnetic properties of the ferrite. A systematic investigation was conducted to understand the influence of porosity, grain size, and microstructure on the magnetic attributes of Ni ferrite ceramics. Under conditions of high pressure (48 MPa) and zero holding time, as the hot-pressing sintering temperature rose from 800°C to 1050°C, the average grain size expanded from 0.4 μm to 3.36μm. Concurrently, the relative density and saturation magnetization initially increased before decreasing. Consequently, a NiCuZn ferrite characterized by uniform, dense grains (GS ave =1.94 μm and D r =99.2 %) and good gyromagnetic properties (4π M s =4703 Gs and Δ H =277 Oe) was achieved through hot-pressure sintering at approximately 950°C.
研究领域:
材料科学
·
电磁学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 4
·2845-2853
·
IF 2.22
Yang Yan,Li Jie,Zhang Huaiwu,Rao Yiheng,Wang Gang,Gan Gongwen
NiCuZn (NCT) ferrites-based ceramics material have received significant attention for good gyromagnetic properties in recent years. Densification and ferromagnetic resonance linewidth play a critical role in modern system including circulators, phase shifters. However, there are still technological challenges associated with its application to achieve high-performance communication system. In this work, we have carried out a analysis of the influence of sintering temperature and time on the dependent structural, tunable gyromagnetic properties of NCZ ferrites. SEM results found that a direct consequence of varying the sintering temperature and time to be on the variation in the grain size, thus adjusting the ferromagnetic resonance linewidth of NCZ ferrites. We also found that sufficient grain growth is adversely affect ferromagnetic resonance linewidth. Finally, uniform and compact NCZ gyromagnetic ferrites were successfully synthesized at a low temperature (~ 880 °C for 3 h). The fine microstructure of NCZ ferrites sintered at 880 °C for 3 h also possessed excellent gyromagnetic properties (high 4 πM s ≈ 3400.29 Gauss, and low Δ H ≈ 158.39 Oe). It was indicated that this greatly low ferromagnetic resonance linewidth of NiCuZn ferrites can be utilized for new generation high-performance microwave devices.
研究领域:
材料科学
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磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2024
·
IF 2.5
Zelai Cheng,Xi Wang,Xingyu Huo,Yulan Jing,Hua Su
Ni 0.42-x/3 Nb x /3 Cu 0.18 Zn 0.4 Mn x Fe 1.98− x O 4− δ ( x = 0–0.1) materials, possessing a high saturation magnetization, high dielectric constant, and narrow ferromagnetic resonance linewidth, were prepared via the solid-phase reaction method. The cation distribution, as well as the dielectric and gyromagnetic properties, were studied in detail. Mn 2+ and Nb 5+ incorporated in the lattice occupy tetrahedral site, causing the redistribution of cation and the reduction of A–B superexchange interaction. This leads to an increase in saturation magnetization followed by a decrease. The introduction of appropriate amounts of Mn 2+ and Nb 5+ ions reduces the magnetocrystalline anisotropy constant | K 1 | and thus reduces the ferromagnetic resonance linewidth ( ΔH ). Furthermore, high polarisability of Mn 2+ and Nb 5+ causes the increase in the dielectric constant of the ferrites. At x = 0.08, excellent gyromagnetic and dielectric properties, including a high dielectric constant ( ε ’ = 15.4@100 MHz), high saturation magnetization (4π M s = 4577 G), and narrow ferromagnetic resonance linewidth (Δ H = 129 [email protected] GHz) for the NiCuZn ferrite, was achieved. Finally, a K-band microstrip circulator operating at 20.8 to 28 GHz was designed. The simulation showed that the isolation of the circulator in the working frequency band is greater than 20 dB, showing the potential of the prepared ferrites in microwave circulators.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Yan Yang,Jie Li,Jianxiong Zhao,Xia Chen,Gongwen Gan,Gang Wang,Linfeng He
Saturation magnetization and ferromagnetic resonance linewidth are important parameters for microwave devices, such as circulator/isolator. Conventional sintering of ferrite ceramics is prevalently performed to promote the densification. Here, we present a new sintering approach for obtaining uniform and dense NiCuZn ferrite ceramics with enhanced gyromagnetic properties at low temperatures. The NiZn-series ferrites (Ni 0.2 Cu 0.2 Zn 0.6 Fe 2 O 3 – 1.0 wt% Bi 2 O 3 +0.5 wt% MnO 2 ) was synthesized by solid reaction routes with new sintering approaches. The results indicate that a one-transient-step sintering process (OTSP) can significantly improve the gyromagnetic properties at low sintering temperatures by suppressing the anomalous grain growth, such as higher saturation magnetization (4π M s = ∼3904 Gauss) and lower ferromagnetic resonance linewidth ( ΔH = ∼170 Oe). Therefore, such a methodology is quite significant due to it provides a referential experience for effective sintering route that can enable broad practical applications, such as other ferrite ceramics.
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Wei Xiang,Lijun Jia,Tingqing Cai,Xuening Han,Mingchao Yang,Huaiwu Zhang
To meet high-power microwave system demands, low-temperature sintered Bi-Li-V substituted YIG ferrites were prepared. The experimental results reveal that Bi 3+ , Li + , and V 5+ occupy the c, a, and d sites of the garnet structure, respectively; the full-site distortion reduces the lattice activation energy, significantly reducing the transformation temperature from perovskite to garnet phase. Additionally, a dual structure with a high percentage of fine grains is observed in the substituted samples, which is an important reason for the large increase in spin-wave linewidth. Isothermal thermodynamic analysis indicates that a sintering mechanism dominated by liquid-phase sintering is conducive to the densification of YIG ferrites. Ferromagnetic resonance linewidth decomposition confirms that, due to the simultaneous increase in the saturation magnetization and the magneto-crystalline anisotropy constant, anisotropy-induced linewidth remains almost unchanged; the dense dual structure leads to a significant reduction in porosity-induced linewidth; ultimately, the ferromagnetic resonance linewidth is greatly reduced.
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Fang Xu,Shuai Xiong,Yan Yang,Hongwei Yang,Yong Ren,Fei Xie,Guixiang Liu,Bo Dai
In this work, LiZnTi ferrites doped with various V 2 O 5 additives were successfully prepared using hot-press sintering. The influences of V 2 O 5 dopant amount and holding time on phase composition, microstructure and gyromagnetic properties of the low-sintered LiZnTi ferrite were studied. Results showed that the grain growth behavior of the LiZnTi ferrites was closely interrelated with dopant amount and holding time as result of changes of critical driving force ( Δg c ). Moreover, the relative density of all the ferrite samples was very high ( ρ r >99 %). However, we found that the longer holding time (can reduce Δg c ), which is benefit for grain growth and improvement of saturation magnetization (4π M s ) of LiZnTi ferrites, resulted in the deterioration of ferromagnetic resonance (FMR) linewidth ( ΔH ) instead. Finally, due to synergistic effect of applied pressure and V 2 O 5 dopant, the LiZnTi ferrite ( x = 0.10) sintered at 900 °C for 10 mins possessed a small average grain size (GS ave. = 0.69 μm ), very high relative density ( ρ r = 99.35 % ) , high saturation magnetization (4π M s = 4193.2 G s) and a relatively low ferromagnetic resonance linewidth ( ΔH = 449.1 Oe).
研究领域:
材料科学
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无机非金属材料
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磁性材料
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电子陶瓷
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功能材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Yan Yang,Jie Li,Huaiwu Zhang,Lichuan Jin,Fang Xu,Gongwen Gan,Gang Wang,Dandan Wen
The demand for high performance microwave devices is increasingly promoting the development of miniaturization, integration and multifunctionalization. Here, a uniform and dense NiCuZn ferrite ceramic with high saturation magnetization and low ferromagnetic resonance linewidth was obtained at 950 °C by adjusting the MnO 2 -Bi 2 O 3 composite additives. The MnO 2 -Bi 2 O 3 composite additives were composed of 0.5 wt% MnO 2 and x wt% Bi 2 O 3 (x = 0.0, 0.5, 1.0, 1.5, 2.0, and 3.0). The phase structure, microstructures and magnetic properties were systematically studied by means of modern measurement techniques. SEM images reveal that appropriate MnO 2 -Bi 2 O 3 additions can promote grain growth and reduce sintering temperatures , which is very advantageous for LTCC technology. In addition, the content of MnO 2 -Bi 2 O 3 additives can significantly reduce ferromagnetic resonance linewidth (FMR) by promoting grain growth and densification at low temperatures. Finally, a uniform and compact NiCuZn ferrite ceramic with an improved 4π M s (~ 3812.5 Gauss), a narrow Δ H (~ 144.6 Oe), and a reduced H c (~ 85.2 A/m) were obtained (at 950 °C) by adding the optimal volume of Bi 2 O 3 additive. It is expected that the improved gyromagnetic performances will allow the NiCuZn ferrite ceramics to be promising candidates for X-band microwave devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 2
·153
·
IF 2.8
Lai Honglan,Xu Fang,Yang Hongwei,Yang Yan,Ren Yong,Liu Guixiang,Dai Bo
In this study, a hot-pressing sintering (HPS) was firstly performed for LiZnTi ferrites sintered from 850 to 1050 °C. To analyze feasibility of co-firing, the as-sintered HPS 1st samples were then subjected to a traditional sintering (TS) process at 950 °C. The influences of sintering temperature and second sintering on the crystal phase formation, microstructure, and gyromagnetic properties of the LiZnTi ferrite were systematically investigated. X-ray diffraction confirmed that all the samples exhibited a pure spinel structure. SEM images indicated that the grain size and bulk density of the samples have increased with the increase in temperature. Due to the second sintering with a long time, all the samples exhibited a secondary growth. The magnetic hysteresis (M-H) loops confirmed that sintering temperature could enhance saturation magnetization intensity and the samples kept a stable value after second sintering. The results of ferromagnetic resonance (FMR) linewidths revealed that the 1000HPS 1st sample had a small value ( ΔH = 298.25 Oe) and could also keep a good and stable value after second sintering. Thus, the LiZnTi ferrite sample prepared by hot-pressing sintering was feasible for co-firing with other ceramic (dielectric ceramic) for microwave applications.
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jingyu Yuan,Jie Li,Yang Xiao,Xinyi Zhu,Siyuan Wang,Yan Yang,Jinliang Zou,Yichao Yan
In this work, In-doped LiZnTi spinel ferrites were successfully synthesized at a low temperature (920 °C) using 2 wt% Bi 2 O 3 as a sintering aid. The effects of In 3+ doping concentration on phase formation, microstructure, gyromagnetic properties, and dielectric properties were investigated. Results showed that all samples exhibited a single spinel phase, and grain growth behavior was strongly influenced by In 3+ doping. Although saturation magnetization decreased with increasing In 3+ content, the real part of the magnetic permeability (μ') increased from 117 (x = 0.00) to 170 (x = 0.09), while maintaining low magnetic loss. Meanwhile, the dielectric constant showed an upward trend (ε' increased from 15.88 to 18.50) with minimal dielectric loss. Regarding gyromagnetic properties, the sample with x = 0.06 exhibited a narrow ferromagnetic resonance linewidth (ΔH) of 240.09 Oe. The combination of high dielectric constant and low linewidth suggests promising potential for low-loss microwave ferrite devices.
研究领域:
材料科学
·
电磁学
·
微波工程
·
固态物理
·
陶瓷材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Yan Yang,Xiqing Xu,Jianxiong Zhao,Bin Wang,Cui Li,Xia Chen,Fang Xu
Saturation magnetization (4π M s ) and ferromagnetic resonance linewidth ( ΔH ) are vital parameters for microwave devices application. The material with high 4π M s and low ΔH is available in microwave frequency. In this work, to synthesize a ferrite material applied to X band, high saturation magnetization LiZnBi ferrite ceramics were selected as matrix. Further, in order to reduce magnetic loss of the LiZnBi ferrites sintered at low temperatures, various nano-TiO 2 were added. Interestingly, the nano-TiO 2 can promote grains growth and suitably enhance saturation magnetization and lower coercivity at low sintering temperature . Meanwhile, the ferromagnetic resonance linewidth ( ΔH ) of the ferrites can also be reduced by introducing more nano-TiO 2 particles. At last, a nano-TiO 2 substituted LiZnBi ferrite ceramics (x = 0.25) with high saturation magnetization (4π M s = ∼3367 G), low coercivity ( H c = ∼146.2 A/m) and low ferromagnetic resonance linewidth ( ΔH = ∼192 Oe) were obtained at 880 °C. The ferrite material is serviceable for X band microwave devices, such as phase shifter and circulator.
研究领域:
材料科学
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电气工程
·
微波技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zelai Cheng,Xingyu Huo,Zhen Zhao,Feng Qiao,Xiuling Yang,Ying Chen,Mingshan Qu,Hua Su
This work presents a miniaturization strategy for ferrite circulators by enhancing the dielectric constant ε r of NiCuZn ferrites and LTCC technology. Highly polarizable Cu 2+ and Ti 4+ substitutions for Ni 2+ and Fe 3+ increase dielectric constant, while non-magnetic Ti 4+ reduces magnetocrystalline anisotropy and narrows ferromagnetic resonance linewidth ΔH , with Cu 2+ concurrently lowering sintering temperatures. In the Ni 0.42-x/2 Cu 0.18+x Zn 0.4 Ti x/2 Fe 1.98-x O 4-δ system, the x = 0.1 composition (sintered at 975 °C) achieves minimal ΔH (82 Oe), ε r ≈ 14.6, and 4π M s ≈ 4219 G, whereas x = 0.6 (sintered at 925 °C) balances ε r ≈ 20.8 with magnetic performance ( ΔH ≈167 Oe, 4π M s ≈ 2117 G), confirming LTCC compatibility. A heterostructured substrate fabricated by co-firing Ni 0.12 Cu 0.78 Zn 0.4 Ti 0.3 Fe 1.38 O 4-δ ferrite (x = 0.6) with a microwave dielectric (50 wt.% SrCu 0.95 Mn 0.05 Si 4 O 10 + 50 wt.% Sr 3 V 2 O 8 ) exhibits controlled interfacial diffusion. HFSS simulations demonstrate that the integrated circulator-filter achieves significant miniaturization with >30 dB harmonic suppression (14-24 GHz) while maintaining in-band performance (| S 21 | < 1 dB, | S 11 | and | S 12 | < -20 dB at 7-12 GHz). The validates high- ε r NiCuZn ferrites and LTCC composite substrates for compact multifunctional microwave components.
研究领域:
微波工程
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材料科学
·
电磁学
·
铁氧体技术
·
集成电路设计
·
陶瓷工艺
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2018
·
IF 2.011
Feng Su,Ziqing Sun,Weike Su,Xianrui Liang
The tautomerism of three benzimidazole compounds: Omeprazole sulfide, 1 , (R)-Lansoprazole, 2 , and Omeprazole sulfone , 3 were investigated by NMR with the effect of variant solvents and temperature. The dielectric constant of the medium and the ability of solvents to form hydrogen bond with the tautomer had a profound effect on the tautomeric equilibration. The chemical shifts and resonance lines of compounds 1–3 differed greatly in different solvent system mainly due to intra- and intermolecular hydrogen bonds. Variable temperature-nuclear magnetic resonance (VT-NMR) experiments showed that at 203 K the two tautomers of compound 1 were separated and determined to be 6:4 and those of compound 3 be 7:3. In contrast, compound 2 presented only one tautomer at the same temperature while the tautomerism was observed again with temperature increasing. The free energy of activation of the tautomeric interchange of compounds 1 – 3 were 13.77 kcal/mol, 13.47 kcal/mol and 13.06 kcal/mol, respectively. Density function theory (DFT) calculations results showed the tautomers of compound 2 had higher energy differences among the three compounds demonstrating only one preferred conformation existed at 203 K. The preferred conformations of compounds 1 and 3 were also given.
研究领域:
化学
·
物理化学
·
光谱学
·
理论化学
✓ 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）