Journal of Superconductivity and Novel Magnetism
·
2023
·Vol. 36
·期 7
·1737-1750
·
IF 1.8
Shan Shuo,Li Jie,Li Pengwei,Wang Yonglun,Pi Siwen,Zhao Xuan
BaFe 12− x Nb x O 19 ( x = 0.00, 0.04, 0.08, 0.12, 0.16, and 0.20) with a nominal composition for M-type hexagonal barium ferrite was prepared using solid-state sintering methods. The microstructure and magnetic properties of hexaferrite were characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM), and vibrating-sample magnetometry (VSM). XRD results revealed that the crystal structure of barium ferrite remained intact after Nb doping, maintaining a single barium ferrite phase. FESEM confirmed the hexagonal crystal structure of the sample. Energy-dispersive X-ray spectroscopy showed increased Nb content and decreased Fe content without the formation of other elements. FTIR revealed bands at 598 and 445 cm −1 corresponding to tetrahedral and octahedral clusters, respectively. The VSM test showed that the saturation magnetization ( M s ), residual magnetization ( M r ), and coercivity ( H c ) initially increased and then decreased with increasing Nb doping, reaching maximum values of 92.297 emu/g, 44.256 emu/g, and 3367.53 Oe, respectively, at x = 0.08.
研究领域:
材料科学
·
磁学
✓ 已验证
DOI
高影响因子
MATERIALS & DESIGN
·
2019
·
IF 5.77
Shuying Shi,Chonghe Xu,Xinqiang Wang,Yongshuai Xie,Yuping Wang,Qing Dong,Luyi Zhu,Guanghui Zhang,Dong Xu
Magnetic fibers adsorbent has attracted more and more attention because of the large surface area and overcoming the disadvantages of easy agglomeration and difficult separation. Adding Fe 3 O 4 nanoparticles into spinning solution followed by electrospinning is a common method to prepare magnetic fibers. In this paper, a new sol-gel method was developed to prepare Fe 3 O 4 fibers, which overcame the disadvantage of low saturation magnetization due to the limited amount of magnetic nanoparticles in spinning solution, and uneven distribution of magnetic nanoparticles in the fibers. Through studying the effect of the proportion of ethanol in the solvent and the amount of solvent on the surface tension, the conductivity and viscosity of the spinning solution, and the spinning solution with the best spinnability were explored. The prepared Fe 3 O 4 fibers had high saturation magnetization and maintained excellent flexibility. They had the advantages of self-supporting without agglomeration, and were easier to magnetically separate than Fe 3 O 4 powder prepared by the same method. In addition, the adsorption and regeneration performances for Pb(II) of Fe 3 O 4 fibers were better than those of Fe 3 O 4 powder. Fe 3 O 4 fibers were suitable for heavy metal adsorbent or adsorbent core, which became another effective strategy to expand the application prospects of magnetic adsorbents.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Applied Materials Today
·
2024
·
IF 7.2
Chuding Zhang,Decai Li,Wenxi Zhao,Shilin Nie,Jingwei Yang
The preparation of high-performance magnetic fluids with high viscosity, high saturation magnetization and high stability, has remained a pivotal challenge limiting the advancement of associated applications. In the present study, we synthesized modified magnetic nanoparticles through an innovative approach combining in-situ carbon nanotube (CNT) generation with chemical co-precipitation. These nanoparticles were then co-coated with OA/PIBA, resulting in the preparation of advanced PAO20-based magnetic fluids. The effects of CNT modification on particle microstructure and magnetic properties were studied by transmission electron microscopy and vibrating sample magnetometer, the magnetoviscous properties of magnetic fluids were studied by a rotating rheometer equipped with a magnetic field module, and the stability of the prepared magnetic fluids under a strong magnetic field was tested by a self-made LC oscillation circuit. The results show that the saturation magnetization of the prepared magnetic fluids surpasses 32 emu/g, while their viscosity reaches a remarkable 6625 mPa·s (at 0.24 T, 100 1/s shear rate and 25 °C), which is significantly higher than that of traditional magnetic fluids (usually about 100 mPa·s). Furthermore, when exposed to a 0.6 T magnetic field, the magnetic fluids could exhibit Rosensweig instability that persists for over 468 h. The stability is at least 93 times superior to that of unmodified PAO20-based magnetic fluids. Based on these encouraging results, it can be fully predicted that the CNT-modified PAO20-based magnetic fluids developed in this study will play a pivotal role in various applications, including sealing, lubrication, and vibration reduction. Their exceptional properties will hold immense promise for numerous engineering applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2024
·
IF 5.8
Juanjuan Wang,Bin Qin,Huirong Li,Yuxin Zhang,Huan Yang,Fang Wang
Ferromagnetic Cr2Te3 nanocrystals, with their high spin–orbit coupling and low symmetry, have attracted considerable attention as rare-earth-free magnetic nanomaterials due to their potential to achieve high magnetic anisotropy. However, their relatively low values of remanence (Mr) and saturation (MS) magnetisation limit their energy product, making them unsuitable for practical applications. Herein, we report a straightforward one-pot heat-injection technique for the synthesis of high-remanence hexagonal Cr2Te3 nanosheets by heterogeneous doping with atoms of M (M = V, Mn and Se). The doped materials provide enhanced Mr and MS at an unchanged Curie temperature (TC), resulting in excellent hard magnetic properties. With Mn doping, the Mr of the matrix increases significantly, reaching 18.38 emu g−1 at 5 K, far exceeding the original undoped Cr2Te3 nanosheets. The nearly square hysteresis loop makes it valuable for many low temperature applications. These results provide a valuable case for tuning the magnetism of ferromagnetic Cr2Te3 by substitutional doping.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 14
·11165-11173
·
IF 2.779
Gan Liqiang,Yang Fei,Liu Jingsong,Cao Lijia,Huang Xu,Yuan Honglan,Xian Cong,Zhang Wanli
Zr substituted Bi 0.5 Y 1.5− x Ca 1+ x Zr x V 0.5 Fe 4.5− x O 12 ( x = 0.00, 0.25, 0.50, 0.75, 1.00) samples were prepared via solid-state reaction method. The structure, morphology, electromagnetic properties of Zr-doped Bi 0.5 Y 1.5− x Ca 1+ x Zr x V 0.5 Fe 4.5− x O 12 were investigated by SEM, XRD, FT-IR, Raman, VSM, impedance analyzer, and vector network analyzer. The results showed that the Zr 4+ and Ca 2+ ions successfully entered the octahedral a-sites and dodecahedral c-sites, respectively. The saturation magnetization increased with the increase of doping concentration in low concentration range. However, the excessive dopant of diamagnetic Zr 4+ ions resulted in a decrease in the saturation magnetization, indicating that the crystal lattice appeared short-range antiferromagnetic order at the d-sites, and the samples changed from ferromagnetism to paramagnetism. Among them, Bi 0.5 Y 1.25 Ca 1.25 Zr 0.25 V 0.5 Fe 4.25 O 12 has the optimum comprehensive properties, M s = 17.254 emu/g, H c = 4.043 Oe, M r = 0.268 emu/g, Δ H = 81 Oe, ε r = 18.68 @ 1 MHz, and tan δ ε = 0.002. The as-prepared material has potential application in communication devices such as circulators and isolators.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Jiangchao Lou,Junhui Liang,Xin Yao,Hong Ma,Yiqing Zhang,Huayu Chen,Laishun Qin,Yuexiang Huang,Ying Zhao,Da Chen
The efficiency of water splitting is primarily hampered by the sluggish kinetics of the oxygen evolution reaction (OER). Recently, increasing attention has been drawn to leverage spin polarization under an external magnetic field. However, the application of a magnetic field requires additional energy consumption and poses design challenges. Herein, we propose a simple defect engineering strategy aimed at aligning spins in paramagnetic materials to achieve an enhanced intrinsic OER activity. The hydrogenated NiFeP with P vacancies demonstrates elevated saturation magnetization (MS) and reduced overpotential (MS = 5.8 emu/mg, η10 = 303 mV) compared to the untreated NiFeP sample (MS = 1.2 emu/mg, η10 = 341 mV). We elucidate the underlying mechanism of the spin magnetic effect on the OER performance and provide insights into the intricate relationship among vacancies, saturation magnetization, spin state alignment, and oxygenated intermediates. These insights contribute to a better understanding and design of catalysts at the spintronic level, paving the way for more efficient water splitting processes.
研究领域:
材料科学
·
电化学
·
催化作用
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2022
·Vol. 25
·期 5
·2200160
·
IF 4.122
Zhigang Zheng,Hongyu Wang,Chengfeng Li,Xinglin Chen,Dechang Zeng,Shengfu Yuan
The effect of quenching temperature on phase structure and magnetocaloric properties of the Mn 0.975 Fe 0.975 P 0.5 Si 0.5 alloys are systematically studied by X-ray diffraction, scanning electron microscope, differential scanning calorimetry, and vibrating sample magnetometer. The Mn 0.975 Fe 0.975 P 0.5 Si 0.5 alloys quenched at 1323, 1073, 873, and 673 K are all crystallized in the hexagonal Fe 2 P-type phase and the phase fraction of the Fe 2 P phase increases with the decreases of quenching temperature. As the quenching temperature decreases from 1323 to 673 K, the crystal lattice of alloys expands and the atoms' occupation is more ordered, while the saturation magnetic moment increases from 3.71 to 4.10 μ B f.u. − 1 The values of thermal hysteresis increase linearly from 30 to 41 K when the quenching temperature is down to 673 K. This enhancement of the first-order magnetic transition (FOMT) yields the maximum value of magnetic entropy change at 5 T increasing by 36%. To obtain excellent comprehensive properties for (Mn,Fe) 2 (P,Si) alloys, the methods of doping B element in the Mn 0.975 Fe 0.975 P 0.5 Si 0.5 alloy are employed to tune the magnetocaloric properties. The results provide insights and systematic understanding into the effect of quenching temperature on the magnetocaloric properties of (Mn,Fe) 2 (P,Si)-based alloys.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Chinese Physics B
·
2023
·Vol. 32
·期 9
·097501
·
IF 1.7
Jian Wu,Bing Lu,Ying Zhang,Yixin Chen,Kai Sun,Daming Chen,Qiang Li,Yingli Liu,Jie Li
Magneto–dielectric properties of Co2Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work. Ba3Co2Fe24−xGdxO41 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) materials are successfully prepared by using solid-state method at 925 °C for 4 h with 2.5-wt% Bi2O3 sintering aids. The content of Gd3+ ion can affect micromorphology, grain size, bulk density, and magneto–dielectric properties of the ferrite. With Gd3+ ion content increasing, saturation magnetization (Ms) first increases and then decreases. The maximum value of Ms is 44.86 emu/g at x = 0.15. Additionally, sites occupied by Gd3+ ions can change magnetic anisotropy constant of the ferrite. Magnetocrystalline anisotropy constant (K1) is derived from initial magnetization curve, and found to be related to spin–orbit coupling and intersublattice interactions between metal ions. The real part of magnetic permeability (μʹ) and real part of dielectric permittivity (εʹ) are measured in a frequency range of 10 MHz–1 GHz. When x = 0.15, material has excellent magneto–dielectric properties (μ' ≈ 12.2 and ε' ≈ 17.61), low magnetic loss (tan δμ ≈ 0.03 at 500 MHz), and dielectric loss (tan δε ≈ 0.04 at 500 MHz). The results show that Gd-doped Co2Z ferrite has broad application prospects in multilayer filters and high-frequency antennas.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2013
·Vol. 29
·期 7
·1524-1533
·
IF 0.869
XIA Juan,SONG Le-Xin,DANG Zheng,SHAO Zhi-Cheng
Fe3O4 nanoparticles with a highly symmetric octadecahedral nanobox structure were fabricated using β-cyclodextrin as a protection agent. A series of composites (CM-1-CM-4) of polyethylene glycol (PEG) and Fe3O4 nanoparticles with
different initial mass ratios were prepared using a colloid process. We found that the shape of the composites depended on the amount of Fe3O4 nanoparticles. In particular, the melting process of PEG was not only influenced by the presence of Fe3O4
nanoparticles, but also by their amount. We also noticed that the crystallinity of PEG lowered upon compositing with Fe3O4 nanoparticles, and decreased as the amount of Fe3O4 nanoparticles increased with the exception of CM-4. Interestingly, the
degradation of PEG was affected by the Fe3O4 nanoparticles, leading to the appearance of different degradation products. Like the initial Fe3O4 nanoparticles, the Fe3O4 components in the composites exhibited typical soft ferromagnetism
but possessed much lower saturation magnetizations. X-ray photoelectron spectroscopy (XPS) experiments revealed that electronic shift occurred from iron to oxygen. The resulting decrease in the electronic density of iron explained the observed decrease in saturation magnetizations of the composites.
The composites induced strong surface-enhanced Raman scattering of organic dyes that depended on the amount of Fe3O4 nanoparticles in the composite. This study contributes to the development of composite materials combining polymers with inorganic nanoparticles.
研究领域:
材料科学
·
纳米技术
·
物理化学
✓ 已验证
DOI
高影响因子
Journal of Superconductivity and Novel Magnetism
·
2024
·Vol. 37
·期 4
·667-675
·
IF 1.6
Wu Diandian,Liu Xiansong,Han Yuyan,Feng Shuangjiu,Lv Qingrong
A sample of Y 2.85 Ca 0.15 Sn 0.08 Ti 0.05 Mn 0.07 Fe 4.8 O 12 doped with four different ions was prepared using the solid method and a subsequent procedure. X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and scanning electron microscope (SEM) were used to analyze the sample’s structural features, elemental distribution, and surface morphology. The study used the B-H magnetic characteristic analyzer and superconducting quantum interferometer magnetic performance measurement system to analyze the magnetic properties of Y 2.85 Ca 0.15 Sn 0.08 Ti 0.05 Mn 0.07 Fe 4.8 O 12 . The correlation becomes more surprising as the frequency increases, indicating a decrease in permeability when the magnetic field H reaches 200 A/m. Ion substitution leads to changes in magnetic crystal anisotropy, affecting permeability as the external magnetic field strength increases. We analyze the correlation between saturation magnetization and temperature in the 520–540 K range and explain the variation of saturation magnetization with temperature. The study shows that saturation magnetization decreases as temperature increases. This result suggests that saturation magnetization decreases as temperature increases. The increased super-exchange effect due to Ti and Mn occupying the (d) sites is much stronger than the reduced effect caused by Sn occupying the (a) sites. Therefore, the saturation magnetization of the Y 2.85 Ca 0.15 Sn 0.08 Ti 0.05 Mn 0.07 Fe 4.8 O 12 sample is higher than that of the undoped sample. The Curie temperature (Tc) of the Y 2.85 Ca 0.15 Sn 0.08 Ti 0.05 Mn 0.07 Fe 4.8 O 12 sample is lower than that of the undoped sample.
研究领域:
材料科学
·
凝聚态物理
·
功能材料
·
磁性材料
·
无机非金属材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Bixian Zhang,Kai Yang,Sihao Jian,Bei Ren,Ziqian Meng,Yinghui Tang,Yang Miao
With the rapid advancement of communication technologies toward higher frequencies and miniaturization, microwave devices are imposing increasingly stringent performance requirements on fundamental magnetic materials. Optimizing the saturation magnetization and dielectric constant of ferrite materials can enhance the transmission efficiency and frequency response of microwave devices, thereby meeting the evolving technical requirements. In this study, we synthesized a series of yttrium iron garnet ferrites with the chemical composition Bi 1.4 Ca 0.3 Y 1.3 Zr 0.15 Sn 0.15 In 0.2 Fe 4.5-x O 12-1.5x (0 ≤ x ≤ 0.3) using the conventional solid-state reaction method. The effects of iron deficiency on the structure and electromagnetic properties of these ferrites were systematically investigated. The results demonstrate that controlled iron deficiency effectively enhances saturation magnetization (4πMs) while reducing dielectric loss (tanδ), without altering the garnet phase structure or dielectric constant (ε'). However, excessive iron deficiency induces the formation of a secondary YFeO 3 phase, severely degrading material properties. The sample with x = 0.2 exhibits outstanding comprehensive performance, with a high saturation magnetization (1903 Gs), an elevated dielectric constant (25.2), and a low dielectric loss (4.67 × 10 -3 ). These high-performance ferrite materials show great potential for applications in next-generation microwave 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
JOURNAL OF MATERIALS RESEARCH
·
2011
·Vol. 26
·期 9
·1072-1075
·
IF 1.402
Ruiyu Wang,Dan Chen,Lulu Ren,Juan Guo,Tianxi Liu
The preparation and characterization of Fe3O4 microtubes by a polymer-based template approach were described. Fe3O4 tubes with diameter of 600 ± 50 nm and an average tube thickness of about 50 nm were fabricated after removing the electrospun polystyrene fiber template. The microtubes were composed of individual Fe3O4 nanocrystals. The synthesis process was ambient, generalizable, inexpensive, and nontoxic. The magnetite tubes thus fabricated behave with a saturation magnetization of 37 emu/g measured in the vibrating sample magnetometer. The microtubes prepared in this way might find potential applications in catalysis, magnetic fluid, and biological field.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）