CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Hongwei Yang,Fang Xu,Yulong Liao,Yong Ren,Guixiang Liu,Yan Yang,Xueying Wang,Bo Dai
In this work, we prepared a type of LiZnTiCu ferrite with a large grain size and enhanced magnetic properties at ∼900 °C by substituting Cu 2+ ions and doping LBSCA glass. Rietveld refinement of XRD patterns indicates that the Fe 3+ ions in B sites are partially replaced by the Cu 2+ ions, which causes the monotone increase of lattice constant . SEM results show that the interaction of CuO nanoparticles and LBSCA glass causes two changes in the grain growth of the LiZnTiCu ferrites. The grain growth is suppressed when the amount of CuO nanoparticles is less than a threshold value (x = 0.05 for 900 °C; x = 0.20 for 875 °C). However, when enough CuO nanoparticles are added, the ferrites possess a large and compact microstructure. The variation of magnetic hysteresis ( M - H ) loops confirms that M s follows the Néel's collinear spinel model with the increasing number of CuO nanoparticles (x ≤ 0.25). Finally, a type of LiZnTiCu ferrite (x = 0.15) with uniform large grains (average size >10 μm) and good magnetic parameters (4π M s = 3457.59 G, H c = 224.4 A/m and B s = 236.4 mT) is obtained at ∼900 °C.
研究领域:
材料科学
·
磁学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Fang Xu,Xiaolei Shi,Yan Yang,Jie Li,Yulong Liao,Jianbo Hu
The regulation strategy of microstructure, either through promoting grain growth or by improving compactness, is highly effective to improve magnetic properties of low temperature sintered ferrite ceramics. Until now, many studies emphasized grain growth, which often leads to deterioration in uniformity. In this work, a dense Bi 2 O 3 -substituted LiZnTi (Li 0.43 Zn 0.27 Ti 0.13 Fe 2.167 Bi 0.003 O 4 ) ferrite with enhanced magnetic properties was obtained, using LBSCA (Li 2 O–B 2 O 3 –SiO 2 –CaO–Al 2 O 3 ) additives (x wt. %, x = 0.00–0.40). Interestingly, SEM images revealed that the appropriate LBSCA glass not only can promote grain growth and enhance compactness of the Bi 2 O 3 -modified LiZnTi ferrite, but also can suppress abnormal grain by facilitating grain boundary diffusion. Moreover, the relationships between microstructural changes and magnetic properties of the LiZnTi ferrite have been discussed in detail. Finally, a compact LiZnTi ferrite with high saturation flux density ( B s = 319.2 mT), low coercivity ( H c = 213 A/m) and high saturation magnetization ( σ s = 69.5 emu/g) were synthesized when the 0.10 wt % LBSCA glasses were added and sintering temperature was ∼900 °C. Meanwhile, the ferrite samples modified with 0.20 wt % LBSCA glasses have uniform and compact grain (∼3.0 μm). Such a sintering strategy is expected to be a referential experience for other advanced ceramics.
研究领域:
材料科学
·
磁性材料
✓ 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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Fei Xie,Huan Liu,Jijie Zhao,Shuai Wen,Minyu Bai,Yang Chen,Yechuan Zhu,Yao Li,Weiguo Liu
Promoting grain growth and optimizing microstructure are valid strategies for enhancing gyromagnetic and microwave dielectric properties of low-temperature sintered ferrite materials. Here, a modified low-temperature sintering technique was attempted for the synthesis of LiZnTi ferrites that have compact microstructure and improved performances. Trace amounts of CuO-Bi 2 O 3 mixtures (0.50 wt%) were adopted as sintering additives to promote grain growth and to reduce the sintering temperature. Meanwhile, Li 0.42 Zn 0.27 Ti 0.11 Fe 2.2 O 4 nanoparticles (∼21.9 nm) were synthesized using a sol-gel auto-combustion method and were used to optimize the microstructure and to restrain abnormal grain growth . XRD Rietveld refinement and SEM images revealed that uniform and dense LiZnTi ferrites with single-phase spinel structure were obtained. Results demonstrated that co-doping of Li 0.42 Zn 0.27 Ti 0.11 Fe 2.2 O 4 nanoparticles and CuO-Bi 2 O 3 mixtures allows low-temperature sintering (900 °C) to be achieved and also promotes grain growth and densification. In particular, LiZnTi ferrites that were modified with 5.00 wt% Li 0.42 Zn 0.27 Ti 0.11 Fe 2.2 O 4 nanoparticles and 0.50 wt% CuO-Bi 2 O 3 sintering additives exhibited narrow ferromagnetic resonance linewidth (Δ H , ∼145 Oe) and low dielectric loss tangent (tan δ ε , ∼2.45 × 10 −4 ) at ∼9.50 GHz, high saturation flux density ( B s , ∼364 mT), and high squareness ratio ( B r / B s , ∼0.89). Such a modified sintering technique at a low sintering temperature, as reported in this work, provides a reference for other advanced ferrites.
研究领域:
材料科学
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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 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.
✓ 已验证
产品关联
DOI
高影响因子
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