JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 27
·1-12
·
IF 2.8
Zeng Shifan,Zhang Cong,Tian Haiming,Yao Guizhi,Shi Huan,Zhu Yong,Chi Shangpeng,Kan Xucai,Liu Xiansong
The magnetic powder Sm 2 Fe 17 N x has recently garnered considerable interest due to its competitive pricing. In this study, the preparation of Sm 2 Fe 17 N x magnetic powder by melt quenching and nitriding process was successfully completed. In order to obtain a higher coercivity, the particle size of the magnetic powder was reduced to a diameter of less than 2 μm through ball milling. It was observed that as the ball milling time was extended, the coercivity of the magnetic powder exhibited a decline that was premature in comparison to the expected results. Additionally, the presence of minute particles of magnetic powder may appear spontaneous combustion phenomenon. Accordingly, Sm 2 Fe 17 N x magnetic powder with high coercivity ( H cj = 842.8 kA/m) was prepared by phosphoric acid passivation process. Through XRD patterns, it was found that the phosphoric acid passivation process markedly enhanced the antioxidant capacity of the magnetic powder. Through SEM images, it is found that the fine magnetic powder exhibits a sheet structure and has strong shape anisotropy. The research indicate that the phosphoric acid passivation process is effective in enhancing the stability of Sm 2 Fe 17 N x magnetic powder and inhibiting the oxidation reaction of magnetic powder during use. This has a beneficial impact on the service life of permanent magnet devices in industrial production.
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 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
Nanoscale
·
2015
·Vol. 7
·期 12
·5395-5402
·
IF 7.394
Shao-jie Li,Da Li,Wei Liu,Zhidong Zhang
Monoclinic Fe3−xCrxSe4 nanostructures (0 ≤ x ≤ 2.5) were synthesized using a high-temperature solution chemical method. With increasing the Cr doping, the peak positions in the X-ray diffraction (XRD) patterns of Fe3−xCrxSe4 nanostructures slightly shifted to lower 2θ values due to the changes in lattice parameters. Expansions in the unit cell volumes of Fe3−xCrxSe4 nanostructures (x > 0.3) may have been responsible for enhancing the ferromagnetic (FM) interaction between magnetic ions, which resulted in a significant increase in the Curie temperature (TC) from 331 K for Fe3Se4 to 429 K for FeCr2Se4, distinctly differing from the magnetic properties of the corresponding bulk materials. A room-temperature coercivity (HC) analysis showed an obvious increase from 3.2 kOe for Fe3Se4 to 12 kOe for Fe2.3Cr0.7Se4 nanostructure, but gradually decreased upon further increasing the Cr content.
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
Nanomaterials
·
2023
·Vol. 13
·期 3
·487
·
IF 5.3
Xiaolei Shang,Xiaoling Men,Qifeng Kuang,Shaojie Li,Da Li,Zhidong Zhang
Organic–inorganic hybrid materials built by inorganic and organic building units have attracted intensive interest in the past decades due to unique chemical and physical properties. However, rare organic–inorganic hybrid materials show excellent permanent magnetic properties. Here, we develop a facile chemical solution method to bottom-up synthesize a new hybrid (Fe2Se3)2[Fe(dien)2]0.9. This hybrid phase with the space groupP21/c(14) possesses a rodlike shape with a diameter of 100–2000 nm and a length of 5–50 µm. The hybrid rods are ferrimagnetic with a Curie temperature (TC) of 11 K. They show a high coercivity (HC) of 4.67 kOe and a saturation magnetization (MS) of 13.5 emu/g at 2 K. Compared with orthorhombic (FeSe2)2Fe(dien)2, the excellent magnetic performance of the hybrid rods is ascribed to the monoclinic hybrid structure built by Fe(dien)2complexes and Fe2Se3double chains. Our study provides guidance for connecting inorganic fragments of FeSe2single chains, Fe2Se3double chains or β-Fe3Se4layers with Fe(dien)2complexes for organic–inorganic hybrid phases with varied crystal structures and magnetic properties.Keywords:organic–inorganic hybrid materials;chemical solution method;Fe2Se3double chains;coercivity
研究领域:
材料科学
·
磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Hongxing Chen,Renquan Wang,Jun Li,Chang Liu,Xiaojiao Yang,Ying Liu
The combination of high coercivity and resistivity is a strong requirement for permanent magnets to resist thermal demagnetization under complex operating conditions. However, this still remains a challenge for conventional strategies, which always sacrifice the maximum energy product as the coercivity or resistivity increases. In this work, we report a unique strategy of introducing only 0.1 wt% of insulating nano-diamonds (NDs) into the hot-deformed Nd-Fe-B magnets to significantly and simultaneously improve both magnetic properties ( H ci , B r , (BH) max and H k / H cj ) and resistivity. In particular, the coercivity increased by 60% from 746 to 1193 kA/m. Further microstructure observations indicate that this exceptional effect stems from NDs can effectively inhibit the formation of coarse grains and optimize the distribution of Nd-rich phases, ensuring a strong pinning effect to enhance hard magnetic performance. Meanwhile, the presence of additional grain boundaries and NDs can also lead to higher resistivity by preventing the movement of free electrons. Our work provides a distinctive strategy for interface modification with excellent comprehensive performance in 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 Today Communications
·
2024
·
IF 3.7
Xiaoyun Shang,Xiangming Wang,Min Chen,Haoran Tu,Hongguo Zhang,Ming Yue,Xiaobo Du
To balance the utilization of rare-earth resources and reduce the preparation cost, the La and Ce substituted Nd 2 Fe 14 C hard magnetic alloys were prepared by a facile mechanochemical method for the first time. A two-step process is typically employed: 1) Decomposition of hydrocarbon and disproportionation of (Nd 1-x RE x ) 2.5 Fe 14 B 0.08 (RE=La or Ce, x=0–0.3) alloys during high-energy ball milling, Nd+Nd 2 Fe 17 +n-hexane→NdH 2+δ +α-Fe+Fe 7 C 3 ; 2) (Nd, RE) 2 Fe 14 C hard magnetic powders were obtained via the vacuum annealing at 800 °C for 2 min. The phase relation, magnetic properties and microstructural evolution of (Nd, RE) 2 Fe 14 B 0.08 C 0.92 (named Nd-RE-Fe-C-based) alloys were systematically investigated. Substitution of La for x=0.1 Nd in the Nd-RE-Fe-C-based alloy increase the coercivity from 15.6 kOe to 18.6 kOe without reducing the remanence. First-principles calculation was performed to study the mechanism of magnetic properties La and Ce substituted samples. The results showed that La tends to be expelled from 2:14:1 phase to form more minor phases which act as the domain wall pinning center, increasing the coercivity. However, Ce prefers to enter the 2:14:1 phase, diminishing the permanent magnetic properties due to the poor intrinsic magnetic properties. This paper provides a novel viewpoint for the effective utilization of high abundant rare earth and the investigation of low cost Nd 2 Fe 14 C permanent magnet materials.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2021
·
IF 4.641
Jie Li,Feng Gao,Gang Wang,Yan Yang,Yahui Sun,Haokai Su,Xuening Han,Huaiwu Zhang,Qiang Li
Herein, Sm-Ga ions substituted MgCd ferrite (Mg 0.77 Cd 0.23 Fe 2-2x Sm x Ga x O 4 , x = 0.00–0.20) were synthesized via solid state method at low temperature using 2 wt% B 2 O 3 -Bi 2 O 3 -SiO 2 -ZnO glass (BBSZ glass) additive. Sm-Ga substitution did not change the spinel phase formation of ferrite. SEM showed that the grain size first increased and then decreased, while the bulk density displayed the opposite trend and the maximum density was 4.646 g/cm 3 at x = 0.10. Owing to Sm-Ga ions substitution, saturation magnetization ( M s ) first increased, and then decreased, while the coercivity ( H c ) decreased first, and then increased. At x = 0.10, the maximum M s was 25.33 emu/g, and the minimum H c was 28.82 Oe. The real part of magnetic permeability reached a maximum (μ' = 56.02 @x = 0.15) and then dropped down. The ferromagnetic resonance linewidth (at 9.56 GHz) was easily influenced by the Sm-Ga ions substitution, with the minimum value of 251.29 Oe at x = 0.10. Hence, the material has potential for microwave devices applications.
研究领域:
材料科学
·
磁学
✓ 已验证
DOI
高影响因子
Journal of Superconductivity and Novel Magnetism
·
2023
·Vol. 36
·期 3
·965-974
·
IF 1.8
Liu Chaocheng,Hu Jiyu,Xu Haifeng
The modulation of ions substitution has been regarded as a promising route to induce magnetic transition and tailor intrinsic properties for spinel ferrites as expected. Herein, Fe-substituted Co(Ga 2- x Fe x )O 4 spinel ferrites have been successfully prepared by a solid-state method. It is shown that the lattice constant increases gradually with the rising amount of Fe substitution due to a larger ionic radius of Fe than that of Ga. More importantly, a significant improvement in magnetic properties has been achieved under the effort of Fe substitution, especially in intrinsic coercivity ( H c ). Correspondingly, the saturation magnetization ( M s ), H c , and Curie temperature ( T C ) increase from 11.01 emu/g, 0.29 kOe, and 10 K to 86.05 emu/g, 11.45 kOe, and 318 K respectively based on Fe substitution. Our work realizes a marked modulation of magnetic properties in Co(Ga 2- x Fe x )O 4 , providing a fundamental strategy for magnetism tuning as well as the development of magnetic devices.
研究领域:
材料科学
·
凝聚态物理
·
磁学与磁性材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 20
·12315-12320
·
IF 3.361
Xiaoyun Shang,Haoran Tu,Jingjing Zhang,Bingying Ni,Liying Wang,Minggang Wang,Chen Wu,Zhankui Zhao
Nd2Fe14B nanoparticles are widely used because of their outstanding hard magnetic properties. In fact, Pr2Fe14B has higher magneto-crystalline anisotropy than Nd2Fe14B, which makes Pr-Fe-B a promising magnetic material. However, the chemical synthesis route to Pr2Fe14B nanoparticles is challenging because of the higher reduction potential of Pr3+, as well as the complex annealing conditions. In this work, Pr2Fe14B nanoparticles were successfully synthesized via an efficient and green mechanochemical method consisting of high energy ball milling, annealing, and a washing process. Microstructural investigations revealed that the oxide precursors were uniformly wrapped by CaO and CaH2, which formed an embedded structure after ball milling. Then, Pr2Fe14B powder was synthesized via a time-saving annealing process. The impact of the Pr2O3 content and the preparation conditions was investigated. The coercivity of the as-annealed powder with 100 wt% Pr2O3 excess is 18.9 kOe. After magnetic alignment, the coercivity, remanence, and maximum energy product were: 9.8 kOe, 78.4 emu g−1, and 9.8 MGOe, respectively. The present work provides a promising strategy for preparing anisotropic Pr-Fe-B permanent magnetic materials.
研究领域:
材料科学
·
纳米技术
·
固体物理
·
磁性材料
✓ 已验证
DOI
高影响因子
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 Research Express
·
2018
·Vol. 5
·期 6
·066106
·
IF 1.151
Renxin Xu,Huan Yang,Huajun Sun,Yueli Liu,Huan Zhou,Jianchun Liu
Mg0.2Mn0.8HoxFe2−xO4 (x = 0.025, 0.050, 0.075 and 0.100) nanocrystalline is synthesized via a hydrothermal technique. Single phase cubic spinel is confirmed by XRD and the formation of Mg0.2Mn0.8HoxFe2−xO4 is verified by EDS. The average size for the nanoferrites is around 80 nm which is examined by TEM with the presence of agglomerated particles. Ho3+ substituted Mg-Mn nanoferrites exhibit the low saturation magnetization (Ms) and coercivity (Hc). Especially, with x = 0.100, the nanoferrites show the lowest Ms and Hc of 46.850 emu g−1 and 46 Oe, respectively. The ferrite composites present the dielectric dissipation less than 0.37 and the magnetic loss less than 0.46 at 2–18 GHz. The low saturation magnetization, low coercivity and low dielectric dissipation indicate that the addition of Ho3+ contributes to synthesize better soft magnetic 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
Nanoscale
·
2017
·Vol. 9
·期 35
·12855-12861
·
IF 7.367
Wenjuan Lei,Yongsheng Yu,Weiwei Yang,Ming Feng,Haibo Li
It is extremely desirable but challenging to develop a facile solution phase synthesis to directly prepare well-dispersed L10-FePt nanoparticles (NPs) to meet the requirements of advanced magnets in modern industry and information technology. Here, we report a novel strategy to synthesize hard magnetic L10-FePt NPs via controlled co-reduction of Fe(acac)3 and K2PtCl6 in the presence of oleylamine, in which effective control of the magnetic properties and chemical ordering of L10-FePt NPs was achieved by tuning the mole ratio of the precursors, reaction time and temperature. The highest coercivity of 10.5 kOe can be obtained for the NPs synthesized at 350 °C for 8 h, which is much higher than the coercivities reported by the previous studies on solution-synthesized FePt NPs without annealing or the third elemental additive. The reported one-pot synthesis of L10-FePt NPs may provide an ideal class of building blocks for magnetic energy applications.
研究领域:
材料科学
·
纳米技术
·
磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）