Journal of Magnetism and Magnetic Materials最新文献

Composition-, temperature-, and field- driven magnetic phase transitions in Bi0.9Ca0.1Fe1-xMnxO3 multiferroics Bi0.9Ca0.1Fe1-xMnxO3多铁质中成分、温度和场驱动的磁相变

IF 2.5 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2024-12-01 DOI: 10.1016/j.jmmm.2024.172703

V.A. Khomchenko, M. Das, J.A. Paixão

{"title":"Composition-, temperature-, and field- driven magnetic phase transitions in Bi0.9Ca0.1Fe1-xMnxO3 multiferroics","authors":"V.A. Khomchenko, M. Das, J.A. Paixão","doi":"10.1016/j.jmmm.2024.172703","DOIUrl":"10.1016/j.jmmm.2024.172703","url":null,"abstract":"<div><div>A magnetometric study of Bi<sub>0.9</sub>Ca<sub>0.1</sub>Fe<sub>1-x</sub>Mn<sub>x</sub>O<sub>3</sub> (0.3 ≤ <em>x</em> ≤ 0.5) compounds was conducted over broad temperature and field ranges to clarify the impact of Mn substitution on the magnetic properties of Ca<sup>2+</sup>-doped bismuth ferrite-based multiferroics near the polar-antipolar phase boundary. Room-temperature X-ray diffraction measurements confirm the stability of the polar rhombohedral <em>R3c</em> structure up to <em>x</em> = 0.4, with a transition to the antipolar orthorhombic <em>Pnam</em> phase occurring through a mixed structural state at <em>x</em>≈ 0.45. Magnetic measurements of rhombohedral-structure samples reveal an evolution in magnetization behavior, indicative of a transformation from the cycloidal spin order, characteristic of low-doped bismuth ferrites, to a collinear antiferromagnetic arrangement as Mn content increases. Magnetic field modifies the collinear antiferromagnetic structure towards a canted antiferromagnetic one. The threshold field for the metamagnetic transformation decreases with decreasing temperature and increasing Mn concentration.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"614 ","pages":"Article 172703"},"PeriodicalIF":2.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural and magnetic properties of Co2FeGa full-Heusler alloy thin films with low Gilbert damping 低吉尔伯特阻尼Co2FeGa全heusler合金薄膜的结构和磁性能

IF 2.5 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2024-11-30 DOI: 10.1016/j.jmmm.2024.172691

Bruno L.D. Santos , Alisson C. Krohling , Klaus Krambrock , Edson C. Passamani , Waldemar A.A. Macedo

{"title":"Structural and magnetic properties of Co2FeGa full-Heusler alloy thin films with low Gilbert damping","authors":"Bruno L.D. Santos , Alisson C. Krohling , Klaus Krambrock , Edson C. Passamani , Waldemar A.A. Macedo","doi":"10.1016/j.jmmm.2024.172691","DOIUrl":"10.1016/j.jmmm.2024.172691","url":null,"abstract":"<div><div>Highly ordered Co<sub>2</sub>FeGa thin films were successfully prepared using direct current magnetron sputtering by adjusting the film growth conditions. This involved making modifications to substrate and annealing temperatures. Structural, chemical, and magnetic properties were systematically studied using global and surface techniques. The results showed a transition from a partially ordered film grown at 300 °C to a highly ordered L2<sub>1</sub> full-Heusler phase at 600 °C. X-ray photoelectron spectroscopy confirmed a stoichiometric Co<sub>2</sub>FeGa alloy for the films, while <sup>57</sup>Fe conversion electron Mössbauer spectroscopy revealed the atomic disorder–order transition induced by high substrate temperatures and/or annealing temperatures. The magnetic properties were found to be strongly influenced by the thermal history of the films. Saturation magnetization reached 1200 kA/m and coercivity was as low as 0.8 mT for the film growth at 600 °C. Ferromagnetic resonance showed that the α-Gilbert damping parameter was significantly affected by growth conditions with a value of 0.0015(3) measured in films grown at the highest temperature. This study demonstrates that precise control over film crystallinity and atomic ordering can lead to low α-damping values in polycrystalline Co<sub>2</sub>FeGa thin films, making them promising materials for use in spintronic devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"614 ","pages":"Article 172691"},"PeriodicalIF":2.5,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimize magnetocaloric properties and preparation efficiency of off-stoichiometric La1.1-xCexFe11.7-yMnySi1.3 hydrides through systematic investigation of the 1:13 phase formation mechanism 通过系统研究1:13相形成机理，优化非化学计量La1.1-xCexFe11.7-yMnySi1.3氢化物的磁热学性能和制备效率

IF 2.5 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2024-11-29 DOI: 10.1016/j.jmmm.2024.172696

Yibo Jin , Jun Wang , Hongchao Li , Tong Wei , Chao Li , Jinshan Li

{"title":"Optimize magnetocaloric properties and preparation efficiency of off-stoichiometric La1.1-xCexFe11.7-yMnySi1.3 hydrides through systematic investigation of the 1:13 phase formation mechanism","authors":"Yibo Jin , Jun Wang , Hongchao Li , Tong Wei , Chao Li , Jinshan Li","doi":"10.1016/j.jmmm.2024.172696","DOIUrl":"10.1016/j.jmmm.2024.172696","url":null,"abstract":"<div><div>The fully hydrogenated La<sub>1.1-x</sub>Ce<sub>x</sub>Fe<sub>11.7-y</sub>Mn<sub>y</sub>Si<sub>1.3</sub> magnetocaloric materials have high magnetic entropy changes while maintaining low hysteresis loss. To significantly improve the magnetocaloric properties and preparation efficiency, the 1:13 phase transition mechanism of off-stoichiometric La<sub>1.1-x</sub>Ce<sub>x</sub>Fe<sub>11.7-y</sub>Mn<sub>y</sub>Si<sub>1.3</sub> ((x,y)=(0.24, 0.16), (0.34, 0.14), (0.44, 0.10)) was studied in detail. The optimal annealing temperature increased with increasing Ce(x), and the La<sub>0.86</sub>Ce<sub>0.44</sub>Fe<sub>11.4</sub>Mn<sub>0.1</sub>Si<sub>1.3</sub> sample annealed at 1423 K for 18 h reached 80 vol% of the 1:13 phase, which was significantly greater than that of the sample annealed at 1373 K for 7 days (69 %). After hydrogenation, the relative cooling power of La<sub>0.86</sub>Ce<sub>0.44</sub>Fe<sub>11.4</sub>Mn<sub>0.1</sub>Si<sub>1.3</sub> annealed at 1423 K for 18 h increased by 40 % (−ΔS<sub>M</sub> = 8.0 J/kgK, δ<sub>FWHM</sub> = 12.5 K) compared with that of the sample annealed at 1373 K for 7 days. The substitution of Ce atoms was found to promote the formation of the 1:13 phase. This work not only conducted an in-depth study on the annealing mechanism of Ce and Mn multielement-substituted La-Fe-Si compounds but also greatly reduced the difficulty of preparing La-Fe-Si materials with high Ce contents, which accelerated the engineering application of this type of material.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"614 ","pages":"Article 172696"},"PeriodicalIF":2.5,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modulation of ferromagnetism through electron doping in Pd-doped β-Ga2O3 通过电子掺杂pd掺杂β-Ga2O3调制铁磁性

IF 2.5 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2024-11-28 DOI: 10.1016/j.jmmm.2024.172693

Yunliang Yue , Min Wang , Weifeng Xie , Jing Lu

{"title":"Modulation of ferromagnetism through electron doping in Pd-doped β-Ga2O3","authors":"Yunliang Yue , Min Wang , Weifeng Xie , Jing Lu","doi":"10.1016/j.jmmm.2024.172693","DOIUrl":"10.1016/j.jmmm.2024.172693","url":null,"abstract":"<div><div>The incorporation of magnetism into semiconductor materials offers promising opportunities for expanding their applications in spintronics. In this study, first-principles calculations are employed to investigate the defect energetics and magnetic properties of Pd-doped β-Ga<sub>2</sub>O<sub>3</sub>, where Pd atoms substitute for Ga atoms. The results reveal that Pd substitution at tetrahedrally coordinated Ga sites incurs significantly higher energy, favoring octahedral coordination instead. Under n-type doping conditions, Pd tends to stabilize in a negatively charged state, contributing to its magnetic behavior. A detailed analysis of the interaction between Pd-Pd pairs demonstrates that ferromagnetism can be effectively controlled by tuning the carrier concentration. Specifically, at optimal n-type carrier densities, a pronounced ferromagnetic interaction is observed, while this effect diminishes with further increases in electron concentration. The findings provide valuable insights into the defect structures, charge states, and magnetic properties of Pd-doped β-Ga<sub>2</sub>O<sub>3</sub>, offering a pathway to manipulating magnetic behavior in semiconductors via carrier concentration modulation, thus paving the way for future spintronic device applications.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"614 ","pages":"Article 172693"},"PeriodicalIF":2.5,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dzyaloshinskii–Moriya interaction gradient driven skyrmion based energy efficient leaky integrate fire neuron Dzyaloshinskii-Moriya相互作用梯度驱动的基于skyrmion的能量高效泄漏集成火神经元

IF 2.5 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2024-11-28 DOI: 10.1016/j.jmmm.2024.172694

Ravish Kumar Raj , Shipra Saini , Ravi Shankar Verma , Brajesh Kumar Kaushik , Sonal Shreya

{"title":"Dzyaloshinskii–Moriya interaction gradient driven skyrmion based energy efficient leaky integrate fire neuron","authors":"Ravish Kumar Raj , Shipra Saini , Ravi Shankar Verma , Brajesh Kumar Kaushik , Sonal Shreya","doi":"10.1016/j.jmmm.2024.172694","DOIUrl":"10.1016/j.jmmm.2024.172694","url":null,"abstract":"<div><div>The performance and energy efficiency of skyrmion-based spintronic devices can be greatly affected by the driving mechanism of skyrmion. Skyrmions in thin films can be efficiently displaced with spin-transfer torques (STT) and spin–orbit torques (SOT) using direct current. However, the utilization of current in these devices leads to the Joule heating issue, that compromises their non-volatility advantage in spintronic devices for neuromorphic computing. Therefore, it is necessary to investigate the alternative driving mechanisms for developing energy-efficient skyrmion based devices. In this work, skyrmion dynamics under Dzyaloshinskii–Moriya interaction (DMI) gradient is investigated. It is observed that the DMI gradient is an efficient way to drive the skyrmions with skyrmion Hall effect (SkHE) and a high longitudinal speed. Additionally, a leaky integrate-and-fire (LIF) neuron at room temperature is designed by employing DMI gradient that is energy efficient as it functions without the need for any current. This neuron utilizes a DMI gradient for integration on a trapezoidal-shaped nanotrack, achieving leaky functionality through the shape of the nanotrack itself. This design eliminates the need for external stimuli and additional hardware, resulting in low energy consumption of 91.363 <em>fJ</em> per spike. This opens a new alternative way to manipulate skyrmions for the development of energy-efficient skyrmion based devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"614 ","pages":"Article 172694"},"PeriodicalIF":2.5,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improving the Curie temperature of monolayer CrBr3 by Li adsorption: A first-principles study 锂吸附提高单层CrBr3居里温度的第一性原理研究

IF 2.5 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2024-11-28 DOI: 10.1016/j.jmmm.2024.172686

Yong Zhang , Zhong-Xiang Xie , Yong-Yi Li , Shi-Zhang Chen , Feng Ning

{"title":"Improving the Curie temperature of monolayer CrBr3 by Li adsorption: A first-principles study","authors":"Yong Zhang , Zhong-Xiang Xie , Yong-Yi Li , Shi-Zhang Chen , Feng Ning","doi":"10.1016/j.jmmm.2024.172686","DOIUrl":"10.1016/j.jmmm.2024.172686","url":null,"abstract":"<div><div>The monolayer CrBr<sub>3</sub>, as an intrinsic magnetic semiconductor, holds great promise for future electronic and spintronic devices. However, the lower Curie temperature (<em>T</em><sub>C</sub>) limits the applications. In this study, we investigated the impact of Li adsorption on the stability, electronic and magnetic properties of monolayer CrBr<sub>3</sub> by performing first-principles calculations. Our results reveal that Li adsorption can lead to a semiconductor-to-half-metal transition, the spin-down band gap exhibits a linear variation in response to the adsorption coverage. Furthermore, Li adsorption can further enhance the Cr magnetic moment, and make the <em>T</em><sub>C</sub> twice as large as that of pristine CrBr<sub>3</sub>. Significantly, the increase in <em>T</em><sub>C</sub> derives from the competition between the stronger ferromagnetic superexchange among Cr-Br-Cr and the weaker direct antiferromagnetic exchange among Cr-Cr. Our results not only offer a simple and feasible approach to modulate the electronic structure and magnetism of monolayer CrBr<sub>3</sub>, but also may open up new prospects for utilizing monolayer CrBr<sub>3</sub> in next-generation nanoelectronic and spintronic devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"614 ","pages":"Article 172686"},"PeriodicalIF":2.5,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improved microwave absorption properties of CoFe2O4/AC nanocomposites from matching electromagnetic characteristics 通过匹配电磁特性改善CoFe2O4/AC纳米复合材料的微波吸收性能

IF 2.5 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2024-11-26 DOI: 10.1016/j.jmmm.2024.172688

Y. Lu , B. Hong , J.C. Xu , J. Li , Y.X. Zeng , X.L. Peng , S. Qiu , X.Q. Wang

{"title":"Improved microwave absorption properties of CoFe2O4/AC nanocomposites from matching electromagnetic characteristics","authors":"Y. Lu , B. Hong , J.C. Xu , J. Li , Y.X. Zeng , X.L. Peng , S. Qiu , X.Q. Wang","doi":"10.1016/j.jmmm.2024.172688","DOIUrl":"10.1016/j.jmmm.2024.172688","url":null,"abstract":"<div><div>In order to eliminate the impact of microwaves on safety and health, the development of microwave absorption materials with strong, thin, light and broad characteristic is particularly important. In this paper, magnetic CoFe<sub>2</sub>O<sub>4</sub> nanoparticles are introduced into the pores of coconut activated carbon (AC) to form CoFe<sub>2</sub>O<sub>4</sub>/AC nanocomposites. The specific surface area and saturation magnetization both decease with the increasing AC content, confirming the existence of CoFe<sub>2</sub>O<sub>4</sub> nanoparticles in AC pores. The microwave absorption performance of CoFe<sub>2</sub>O<sub>4</sub>/AC nanocomposites are all greatly enhanced due to impedance matching. Specifically, S-8 (The molar ratio of AC:CoFe<sub>2</sub>O<sub>4</sub> = 8:1) demonstrates a remarkable minimum reflection loss (RL<sub>min</sub>) of −42.99 dB and an effective absorption bandwidth (EAB) of 0.96 GHz at a thickness of 5.5 mm. Moreover, S-12 exhibits an RL<sub>min</sub> of −24.00 dB and a broader EAB of 3.44 GHz at 1.5 mm. The exceptional microwave absorption performance of the CoFe<sub>2</sub>O<sub>4</sub>/AC nanocomposites can be attributed to a synergy of dielectric loss, magnetic loss, and impedance matching mechanisms. These mechanisms encompass interface polarization, dipole polarization, Debye relaxation, natural loss, conduction loss, eddy current loss, as well as multiple reflection and scattering effects.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"614 ","pages":"Article 172688"},"PeriodicalIF":2.5,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Compositional optimization of rare earth permanent magnetic alloy by machine learning 基于机器学习的稀土永磁合金成分优化

IF 2.5 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2024-11-24 DOI: 10.1016/j.jmmm.2024.172685

Lingyao Zhang , Tianhao Su , Yaning Cui , Guanhua Qin , Shihui Yan , Shunbo Hu , Xu Sun , Li Yang , Hang Su , Wei Ren

{"title":"Compositional optimization of rare earth permanent magnetic alloy by machine learning","authors":"Lingyao Zhang , Tianhao Su , Yaning Cui , Guanhua Qin , Shihui Yan , Shunbo Hu , Xu Sun , Li Yang , Hang Su , Wei Ren","doi":"10.1016/j.jmmm.2024.172685","DOIUrl":"10.1016/j.jmmm.2024.172685","url":null,"abstract":"<div><div>Machine learning (ML) is becoming increasingly crucial in the process of discovering and designing new materials. In this paper, we use the quaternary permanent magnetic alloy R(Co<sub>1-</sub><em><sub>x</sub></em><sub>-</sub><em><sub>y</sub></em>Fe<em><sub>x</sub></em>M<em><sub>y</sub></em>)<sub>5</sub> (0 ≤ <em>x</em> ≤ 0.08, 0.08 ≤ <em>y</em> ≤ 0.16) as an example to show how ML can be used in rare earth materials research. Our density functional theory (DFT) high-throughput screening, guided by the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) method, ranks the synthesis difficulty of M−site substituted components as follows, from least to most challenging: Hf, Zr, Cu, Zn/Ni, Ti, Si, and Cr. The magnetic-property data is then used to train and test active ML models, supplemented by Markov chain Monte Carlo (MCMC) iterations. Our model forecasts that substituting rare earth sites with Gd and Eu, and the Co site with Cr or Ni, can result in magnetic moments on par with or exceeding SmCo<sub>5</sub>. We further employ our model to optimize compositions and predict cost-effective, supply-reliable alternatives to SmCo<sub>5</sub>, particularly for those with lower Sm and Co content. ML is thus beneficial for compositional optimization, especially when the underlying structure–property relationships are not fully understood.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"614 ","pages":"Article 172685"},"PeriodicalIF":2.5,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Magnetic field-assisted construction of ordered ferromagnetic nanowire fibers with enhanced microwave absorption and high stability electromagnetic interference shielding 磁场辅助构建具有增强微波吸收和高稳定性电磁干扰屏蔽功能的有序铁磁纳米线纤维

IF 2.5 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2024-11-24 DOI: 10.1016/j.jmmm.2024.172678

Ping-an Yang , Chensong Zhao , Lihua Zou , Mengjie Shou , Yuxin Zhang , Wenxian Ye , Jiufei Luo

{"title":"Magnetic field-assisted construction of ordered ferromagnetic nanowire fibers with enhanced microwave absorption and high stability electromagnetic interference shielding","authors":"Ping-an Yang , Chensong Zhao , Lihua Zou , Mengjie Shou , Yuxin Zhang , Wenxian Ye , Jiufei Luo","doi":"10.1016/j.jmmm.2024.172678","DOIUrl":"10.1016/j.jmmm.2024.172678","url":null,"abstract":"<div><div>The use of electromagnetic interference (EMI) fabrics spun with metal fibers is an effective measure for personal protection against high electromagnetic radiation. To address the limitations of traditional metal fiber-coated shielding effectiveness (SE) fabrics, which often underperform, this study proposes the development of ferrimagnetic fiber composites with excellent absorption properties. By employing magnetic field structuring to create an ordered structure, the goal is to produce shielding fabrics with high absorption SE and strong mechanical stability. This paper introduces a magnetic field ink control method to construct an ordered conductive network. The EMI SE of fabrics prepared using the magnetic ink control method reached 40.74 dB, which is higher than that of samples prepared using simpler control methods (34.76 dB). The fabric prepared with this method retains 88 % and 92 % of its original EMI SE after 1000 bending and 500 twisting cycles, respectively, which is significantly better than the performance of samples prepared with simpler control methods (54 % and 48 %). The Specific Absorption Rate (SE<sub>A</sub>/SE) is 93 %, higher than the 87 % achieved by simpler methods. This work provides a new approach for the development of high-EMI SE fabrics.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"613 ","pages":"Article 172678"},"PeriodicalIF":2.5,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanism of hysteresis effect in levitation electromagnet under large gap fluctuation and its influence on dynamic performance 大间隙波动下悬浮电磁铁磁滞效应的机理及其对动态性能的影响

IF 2.5 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2024-11-24 DOI: 10.1016/j.jmmm.2024.172684

Qinghui Liu, Miao Li, Weihua Ma, Jing Liu, Shihui Luo, Longquan Qin

{"title":"Mechanism of hysteresis effect in levitation electromagnet under large gap fluctuation and its influence on dynamic performance","authors":"Qinghui Liu, Miao Li, Weihua Ma, Jing Liu, Shihui Luo, Longquan Qin","doi":"10.1016/j.jmmm.2024.172684","DOIUrl":"10.1016/j.jmmm.2024.172684","url":null,"abstract":"<div><div>The levitation electromagnets of EMS(Electromagnetic Suspension) maglev trains are made of ferromagnetic materials, and hysteresis is an inherent property of these materials. Under large gap fluctuation (≥4mm), the input DC current experiences significant interference, affecting the stability and safety of vehicle operation and control due to the levitation electromagnet hysteresis effect.. To study this hysteresis effect under large gap fluctuation, firstly, the hysteresis mathematical model of the levitation electromagnet is established based on the Jiles-Atherton Hysteresis Theory. Secondly, the voltage equation and electromagnetic force equation of a single electromagnet under the hysteresis effect are derived based on the equivalent magnetic circuit method. Finally, a Simulink model of the levitation electromagnet is established, and the levitation electromagnet hysteresis effect on the dynamic performance of EMS maglev train under various excitations with large gap fluctuation (≥4mm) is analyzed. The results show that: 1) Under large gap fluctuation, the magnetic flux density of the levitation electromagnets only moves within the upper region of the limit hysteresis loop, which is irregular and causes strong noise interference at both peak and valley accelerations; 2) under the hysteresis effect, when the external excitation amplitude remains constant, the vibration of the levitation electromagnet intensifies with increasing excitation frequency; 3) When the vibration acceleration of the levitation electromagnet is greater than 2.5 m/s<sup>2</sup>, the fluctuation of magnetic flux density is drastic and there is a significant instantaneous mutation.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"613 ","pages":"Article 172684"},"PeriodicalIF":2.5,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0