JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2015
·
IF 1.97
Pingyuan Meng,Kun Xiong,Kui Ju,Shengnan Li,Guangliang Xu
To achieve stronger microwave attenuation and larger bandwidth in electromagnetic absorber, the nickel ions (Ni 2+ ) and manganese ions (Mn 2+ ) were employed to partially replace the cobalt ions (Co 2+ ) in BaCoTiFe 10 O 19 , and the doped barium hexaferrite (Ba(MnNi) 0.2 Co 0.6 TiFe 10 O 19 and Ba(MnNi) 0.25 Co 0.5 TiFe 10 O 19 ) powders were synthesized via the sol–gel combustion method. Subsequently, the microwave absorbing composites were prepared by mixing the ferrite powders with the paraffin. The X-ray diffraction (XRD) patterns of the doped ferrites confirmed the formation of the M-type barium ferrite , and no other types of barium ferrite could be found. Based on the electromagnetic parameters measured by the vector net-analyzer, it was found that the composite (Ba(MnNi) 0.2 Co 0.6 TiFe 10 O 19 ) possessed a minimum reflection loss of −52.8 dB at 13.4 GHz with a matching thickness of 1.8 mm and the bandwidth below −15 dB was 5.8 GHz. Moreover, the maximum attenuation of Ba(MnNi) 0.25 Co 0.5 TiFe 10 O 19 could reach −69 dB when its thickness was 1.8 mm, and also the bandwidth less than −20 dB was ranging from 13.2 GHz to 18 GHz. Thus, Ba(MnNi) 0.2 Co 0.6 TiFe 10 O 19 and Ba(MnNi) 0.25 Co 0.5 TiFe 10 O 19 could be the good microwave absorbers, which have great potentials to be applied in the high frequency fields of the microwave absorbing materials.
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 Superconductivity and Novel Magnetism
·
2018
·Vol. 32
·期 5
·1279-1284
·
IF 1.142
Hu Hao,Niu Xiaofei
Magnetoplumbite-type (M-type) barium ferrites doped with different Y–Co doping content Ba 0.95 Y 0.05 Fe 12− x Co x O 19 ( x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5) were successfully prepared by ceramic process and investigated in this paper for the first time. X-ray diffraction were used to analyze the phase of the prepared sample. The scanning electron microscopy (SEM) was used to measure the morphology, and magnetic properties were measured by vibrating sample magnetometer (VSM). The results of XRD show that the single phase of M-type barium ferrites was obtained with the increase of Co content ( x ), but α -Fe 2 O 3 occurred when x exceeds 0.3. The SEM results exhibit the uniform plane hexagonal structures of M-type ferrites with all range of Co doping content. VSM results display that magnetization ( M s ) and coercivity ( H c ) show the same tendency that their values first increase and then decrease with the increase of Co content.
研究领域:
材料科学
·
磁性材料
·
无机功能材料
✓ 已验证
DOI
高影响因子
Journal of Superconductivity and Novel Magnetism
·
2022
·Vol. 36
·期 1
·327-341
·
IF 1.675
Li Pengwei,Li Jie,Wang Yonglun,Yao Kai,Shan Shuo,Suo Xing,Ma Saisai
Praseodymium (Pr)–aluminum (Al)-co-doped M-type barium ferrite with Ba 0.85 Pr 0.15 Fe 12-x Al x O 19 ( x = 0.0–1.0) was prepared by combining solid-phase sintering with high-energy ball milling. The samples were characterized using a thermogravimetric analyzer, X-ray diffractometer, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometer. Thermogravimetric analysis indicated that M-type barium ferrite was formed at 1250 °C. X-ray diffraction patterns showed that Al doping did not destroy the crystal structure of barium ferrite. Field emission scanning electron microscopy showed that the samples had a hexagonal crystal structure. The wave numbers of Fourier transform infrared spectroscopy in the 597–607 and 452–459 cm −1 bands represent tetrahedral and octahedral clusters, respectively. With the increase in the amount of Al doping ( x ) from 0.0 to 1.0, the saturation magnetization ( M s ) and residual magnetization ( M r ) decreased continuously, and the magnetic anisotropy field ( H a ) and coercivity ( H c ) increased significantly.
研究领域:
材料科学
·
无机化学
·
磁性材料
·
固体物理
✓ 已验证
DOI
高影响因子
Journal of Superconductivity and Novel Magnetism
·
2022
·Vol. 35
·期 9
·2473-2484
·
IF 1.675
Li Pengwei,Li Jie,Zhang Wenhao,Wang Yonglun,Yao Kai
Pr-doped M-type barium ferrite with a composition of Ba 1− x Pr x Fe 12 O 19 (0.00 < x < 0.25) was prepared via solid-state sintering combined with high-energy ball milling. The structures, spectra, morphologies, and magnetic properties of Pr 3+ -substituted Ba hexaferrites were analyzed herein. Under high-energy ball milling, the material produces crystal vacancy defects for elemental doping. The X-ray diffraction results showed that the hexagonal crystal structure was affected when the Pr content ( x ) was > 0.20. The GSAS refinement results show that the synthesized samples were good. The scanning electron microscopy results and Fourier transform infrared (FT-IR) spectra of the tetrahedral and octahedral sites (FT-IR result of the Fe–O bond = 601 and 448 cm −1 peaks, respectively) of the prepared material proved the formation of a hexagonal crystal structure. The magnetic properties of the samples were measured using a vibrating sample magnetometer at room temperature, and the obtained results demonstrated that the coercivity increased with an increase in the doping amount (from 3815.03 at x = 0 to 4600.56 kOe at x = 0.25). At the same time, the saturation magnetization maintained its high value (> 72.568 emu/g), which is beneficial for preparing permanent magnets.
研究领域:
材料科学
·
磁学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
Yanli Deng,Lutong Li,Long Wang,Na Wu,Huihui Jin,Feng Gao,Zhihui Zeng
W-type ferrites possessing low cost and high chemical stability, show high potential in electromagnetic wave (EMW) absorption field. However, due to the low dielectric loss, developing high EMW absorption performance of W-type ferrites remains desired. Here, rare earth (RE) cerium (Ce)-doped W-type barium ferrites (Ba 1-y Ce y Ni 2 Fe 15.4 O 27 , y=0.1, 0.2, 0.3, 0.4, 0.5, 0.6) are prepared by a sol-gel approach. The influences of Ce doping are detailed analyzed. Ce ions with unpaired 4f electrons and strong spin-orbit coupling of angular momentum enhance the dielectric and magnetic properties of ferrites. Ba 0.7 Ce 0.3 Ni 2 Fe 15.4 O 27 achieves the minimum reflection loss (RL min ) value of -52 dB while Ba 0.6 Ce 0.4 Ni 2 Fe 15.4 O 27 showcases the widest effective absorption bandwidth (EAB) of 1.36 GHz associated with the RL min reaching -38 dB, significantly outperforming the undoped ferrites. This work thus demonstrates a high-efficiency utilization of Ce for enhancing the EMW absorption performance of widely employed W-type barium ferrites, efficiently advancing the application field of RE elements.
研究领域:
材料科学
·
电磁学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2021
·
IF 2.993
Guanghui Han,Rui Sui,Yongsheng Yu,Li Wang,Menggang Li,Ji Li,Hu Liu,Weiwei Yang
Ion substitution is considered to be one of the efficient approaches to improve the magnetic properties of the barium hexaferrites. In this work, we fabricated BaFe 12− x Al x O 19 ( x = 0, 1, 2, 4, 6) via a simple auto-combustion method and investigated their structures, morphologies and magnetic properties. The coercivity is greatly affected by annealing temperature and Al 3+ content. In addition, the Al 3+ substitution sites in BaFe 12− x Al x O 19 were further investigated by the Mössbauer spectroscopy and the superparamagnetic components were found in the BaFe 8 Al 4 O 19 and BaFe 6 Al 6 O 19 . The highest coercivity of 13.7 kOe was achieved in the BaFe 8 Al 4 O 19 , which increases by 168.6% compared with that of BaFe 12 O 19 . This work opens up a new and meaningful insight for the understanding of microstructure and coercivity mechanism towards the Al 3+ substituted barium hexaferrites.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2023
·
IF 3.8
Shuo Shan,Jie Li,Xuan Zhao,Siwen Pi
M-type barium ferrite with the formula Ba 1− x Sm x Fe 12− y Nb y O 19 ( x = 0.00–0.10, y = 0.00–0.20), which was co-doped with Sm 3+ and Nb 5+ ions, was synthesized experimentally by a modified solid-phase reaction method. The crystal structure of samples was determined by X-ray diffraction, which confirmed that they were of high purity. The X-ray diffraction data were fitted with a full-spectrum correction using GSAS software. By Fourier transform infrared spectroscopy, the samples were observed to exhibit bands due to tetrahedral and octahedral sites at 598 cm −1 and 445 cm −1 , respectively. The samples were examined by field emission scanning electron microscopy, which showed that they partly comprised hexagonal structures but mostly consisted of irregular structures with rounded edges. Characterization of the elemental contents of the samples by energy-dispersive spectroscopy revealed an increase in the contents of Sm and Nb and a decrease in the contents of Ba and Fe. The magnetic properties of the samples were examined using a vibrating sample magnetometer. The results showed that the saturation magnetization and residual magnetization of the samples decreased slightly with an increase in the contents of the dopants. The coercivity reached its maximum value, namely, 3367.53 Oe, when x = 0.04 and y = 0.08.
研究领域:
材料科学
·
磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Xueying Wang,Yida Lei,Liang Shi,Jie Li,Lichuan Jin,Yulong Liao,Kui Liu,Huaiwu Zhang
The adjustment of crystal structures and properties by ion substitution has received increasing interest in recent years to solve issues related to the preparation of LTCC microwave devices. In this work, Fe 3+ ions were substituted in BaFe 12 O 19 sintered at a low temperature (920 °C). The changes in microstructures, dielectric characteristics, and magnetic properties were all examined. The ferromagnetic resonance linewidth (Δ H ) of BaM ferrite was measured at magnetic fields from 6000 to 24,000 Oe. The results revealed well-grown microstructures of BaM ferrite grains at 920 °C to form typical hexagonal structures. The increase in substitution of Ga 3+ ions decreased the lattice constant and cell volume of the crystals. More interestingly, the dielectric and magnetic properties depicted significant changes in the original dielectric and magnetic parameters of BaM after the substitution of Ga 3+ ions. The permittivity ( ε′ ) rose to a maximum of 16.36 at x = 0.4, while the dielectric loss angle tangent (tan δ ε ) declined to 1.2 × 10^ −3 . As Ga 3+ ions rose, the saturation magnetization 4π Ms decreased from 3168.58 Gauss to 2571.18 Gauss. The remanence ( Mr ) reached a maximum value of 31.07 emu/g at x = 0.4. The ferromagnetic resonance linewidth (Δ H ) of BaM ferrite sample at 31 GHz attained a minimum value of 4216.336 Oe at x = 0.8. In sum, these findings look promising for future fabrication of LTCC microwave RF devices.
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
·
2025
·
IF 5.6
Fengxin Ye,Xiaojian Guo,Yucheng Chen,Lichun Cheng,Qingrong Yao,Zhao Lu,Huaiying Zhou
In this paper, BaFe 12 O 19 (BFO) and Ce x Ba 1- x Fe 12 O 19 (CBFO- x , x = 0.1, 0.15, 0.2) were successfully synthesized using the sol-gel method. The study comprehensively explored the impact of incorporating elemental Ce on the structure and properties of barium ferrite. The results revealed that the introduction of Ce induced alterations in the microstructure of barium ferrite, enhancing its interfacial polarization and defect polarization. The interaction among ions increased the charge polarization and dipole polarization within the material. Additionally, the influence of Ce doping on the complex dielectric constant of BFO materials was investigated in this paper. The results demonstrate that Ce doping significantly enhances the dielectric performance of the material. The Cole-Cole Circle vividly illustrates the presence of multiple loss mechanisms that contribute to the dissipation of electromagnetic waves. Remarkably, the material exhibited a minimum reflection loss (RL) of −46.56 dB at x = 0.2 with a thickness of only 2.4 mm. Furthermore, at x = 0.15, the effective absorption bandwidth of the sample reached 4.16 GHz, highlighting its versatile applications. In comparison with other modifications of barium ferrite, this material offers a simple preparation process and excellent workability. The exceptional reflection loss and broad effective absorption bandwidth make it applicable across diverse fields.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
RARE METALS
·
2018
·Vol. 40
·期 4
·981-986
·
IF 1.5
Shen Si-Yun,Zheng Hui,Zheng Peng,Wu Qiong,Deng Jiang-Xia,Ying Zhi-Hua,Zheng Liang
In this paper, single-phase and fine-grain hexagonal barium ferrite powder was prepared based on the optimal calcination condition. The influence of calcination conditions including temperature and holding time on microstructure and magnetic properties of powder were studied in detail. Firstly, θ –2 θ scan X-ray diffraction (XRD) results reveal that it is hard to obtain single phase of powder when the calcination temperature is lower than 850 °C. In addition, the calcination time for single phase of barium ferrite powder was reduced with the increase in calcination temperature. Scanning electron microscopy (SEM) images and magnetic hysteresis loops show that the condition of low temperature and long holding time is beneficial for obtaining homogeneous size of grain and excellent magnetic properties. Consequently, hexagonal barium ferrite powder with uniform grain size of ~ 180 nm, high purity and excellent magnetic properties is obtained at optimal calcination condition of 850 °C–10.0 h.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2025
·Vol. 32
·期 3
·645-656
·
IF 7.2
Wang Long,Liu Jiurong,Xie Shenghui,Deng Yanli,Wang Zhou,Hou Shanyue,Yue Shengying,Wang Gang,Wu Na,Zeng Zhihui
W-type barium–nickel ferrite (BaNi 2 Fe 16 O 27 ) is a highly promising material for electromagnetic wave (EMW) absorption because of its magnetic loss capability for EMW, low cost, large-scale production potential, high-temperature resistance, and excellent chemical stability. However, the poor dielectric loss of magnetic ferrites hampers their utilization, hindering enhancement in their EMW-absorption performance. Developing efficient strategies that improve the EMW-absorption performance of ferrite is highly desired but remains challenging. Here, an efficient strategy substituting Ba 2+ with rare earth La 3+ in W-type ferrite was proposed for the preparation of novel La-substituted ferrites (Ba 1− x La x Ni 2 Fe 15.4 O 27 ). The influences of La 3+ substitution on ferrites’ EMW-absorption performance and the dissipative mechanism toward EMW were systematically explored and discussed. La 3+ efficiently induced lattice defects, enhanced defect-induced polarization, and slightly reduced the ferrites’ bandgap, enhancing the dielectric properties of the ferrites. La 3+ also enhanced the ferromagnetic resonance loss and strengthened magnetic properties. These effects considerably improved the EMW-absorption performance of Ba 1− x La x Ni 2 Fe 15.4 O 27 compared with pure W-type ferrites. When x = 0.2, the best EMW-absorption performance was achieved with a minimum reflection loss of −55.6 dB and effective absorption bandwidth (EAB) of 3.44 GHz.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2022
·
IF 11.322
Ya-Nan Gao,Ye Wang,Tian-Ning Yue,Ming Wang
High conductivity can give materials excellent electromagnetic shielding performance, but it leads to serious impedance mismatching and causes inevitable secondary pollution. Developing materials with both excellent microwave absorption and microwave shielding performance remains a formidable challenge. Herein, absorption-type electromagnetic shielding materials with high electromagnetic shielding effectiveness (EMW SE) values were successfully prepared by combining hollow silver micro-tubes and magnetic nano-barium ferrites. The electromagnetic parameters and impedance matching of the composites could be easily regulated by changing the ratio of silver micro-tubes (C) and nano-barium ferrites (M). Thanks to micro-tube structure and the electric-magnetic synergism of the fillers, the composites with the C:M ratio of 9:1 exhibited a high absorption coefficient ( A ) value of ∼0.77 and a high EMW SE value of ∼100 dB, simultaneously. The absorption-type shielding mechanism of the composites was also evaluated via discussing real and imaginary parts of complex permittivity , real and imaginary parts of complex permeability, and Cole-Cole curves. Furthermore, the composites with the C:M ratio of 3:7 exhibited excellent microwave adsorption performance with the minimum reflection loss of −46.3 dB at thickness of 3.0 mm and a maximum effective absorption band-width of 6.13 GHz.
研究领域:
材料科学
·
电磁学
✓ 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）