IEEE Transactions on Magnetics最新文献

{"title":"Magnetic Source Localization Based on Magnetic Dipole-Array Method for Demagnetizing Field Estimation","authors":"T. Fukui;T. Shibuya;Y. Adachi","doi":"10.1109/TMAG.2026.3691121","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3691121","url":null,"abstract":"In this study, we address magnetic source localization under conditions where both the source and magnetic sensors are placed close to magnetic shielding material. In such environments, the magnetic field generated by the magnetic source is distorted by demagnetizing fields induced by the magnetic shielding material, leading to degradation of estimation accuracy. To address this problem, we apply the magnetic dipole-array method (MDM), previously proposed to account for the influence of demagnetizing fields, to magnetic source localization. In addition, we design a cylindrical magnetic dipole array specifically for cylindrical magnetic shields, in contrast to the planar dipole-array configurations for rectangular magnetic shields used in our previous studies. Experiments of magnetic source localization using coils, room-temperature magnetic sensors, and a compact cylindrical magnetic shield were conducted. The results showed that the proposed method improved the estimation accuracy, reducing the average position error from 2.7 to 0.59 mm compared with conventional approaches that do not account for demagnetizing fields. This study provides a fundamental investigation under controlled experimental conditions as a basis for future application of MDM to biomagnetic measurements.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"4001205-4001205"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thickness Dependence of Anisotropic Magnetoresistance in CoPt Alloy Multilayer Nanowires Fabricated by Dual-Bath Electrodeposition","authors":"Rio Kawana;Daiki Oshima;Mikiko Saito;Takayuki Homma;Takeshi Kato;Teruo Ono;Mutsuhiro Shima;Keisuke Yamada","doi":"10.1109/TMAG.2026.3697825","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3697825","url":null,"abstract":"We investigated the dependence of anisotropic magnetoresistance (AMR) on the layer thickness and Co composition of Co-rich/Pt-rich CoPt alloy multilayer nanowires fabricated by dual-bath electrodeposition using nanoporous templates. Single-nanowire current-perpendicular-to-plane (CPP) electrical transport measurements revealed that reducing the individual layer thickness to a few nanometers significantly enhanced the AMR ratio, yielding a value that was 2.7<inline-formula> <tex-math>$times$ </tex-math></inline-formula> higher than that of single-layer CoPt alloy nanowires. This enhancement might be attributed to increased interfacial spin-dependent scattering in the multilayer structure under CPP transport. In addition, the Co composition of the Co-rich layers had little effect on the AMR ratio in the high-field saturation region. In contrast, clear differences in AMR behavior were observed at low magnetic fields, indicating that the Co composition influenced the magnetization rotation process rather than the intrinsic anisotropic resistance. These findings elucidated the mechanisms underlying AMR enhancement in multilayer nanowires and provided insight into interface-dominated spin-dependent transport for the development of high-density magnetic sensors and magnetic memory devices.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"2301206-2301206"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Suppression Strategy of Torque Ripple for Permanent Magnet Synchronous Motors Based on Artificial Intelligence Algorithms","authors":"Yan Hu;Kai Yang;Xiaojun Wang;Qiong Liu;Fei Xiong;Yixiao Luo;Cheng Luo","doi":"10.1109/TMAG.2026.3694404","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3694404","url":null,"abstract":"To suppress torque ripple, stator tooth shaping and rotor auxiliary slot opening on a permanent magnet synchronous motor (PMSM) are conducted in this article. Meanwhile, to avoid excessively affecting other performance characteristics of the motor, a multiobjective optimization algorithm based on an artificial intelligence model is employed to explore the most optimal scheme possible. First, finite element analysis (FEA) is used to establish models of the motor before and after optimization design. Subsequently, a parametric sweep is performed on the optimized motor model to calculate the average output torque and torque ripple for each design scheme, followed by a comparative analysis of the motor’s performance before and after the optimization. The results demonstrate that the stator tooth shaping and rotor auxiliary slot opening, along with the subsequent multi-objective optimization, significantly reduce the torque ripple of the motor. Moreover, the average output torque remains almost unaffected.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"8203705-8203705"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Sine-Type Rotor Design on Electromagnetic Vibration Characteristics of Surface-Mounted Permanent Magnet Synchronous Machines","authors":"Rupeng Zhao;Yuhan Cheng;Zhonghe Xu;Yongxiang Xu;Jibin Zou","doi":"10.1109/TMAG.2026.3697576","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3697576","url":null,"abstract":"The sinusoidal rotor field design alters the harmonic distribution of electromagnetic force waves in surface-mounted permanent magnet synchronous machines (PMSMs), exerting a complex influence on electromagnetic vibration. First, the analytical expressions for electromagnetic force waves are derived theoretically, revealing the harmonic coupling mechanism and its phase relationships. Second, finite element models of both tile-shaped and sine-type permanent magnet motors are established, and a comparative analysis is performed on the harmonic characteristics of the no-load back electromotive force (back EMF) and the frequency spectrum of electromagnetic force waves. Subsequently, a vibration calculation model is constructed to clarify the differential effects of the sine-type design on the zeroth-mode vibration and the minimum nonzero mode vibration. The study shows that the sine-type design makes the electromagnetic force waves more sinusoidal, but it increases the amplitude of the second temporal harmonic of the electromagnetic force, significantly amplifies the minimum non-zero mode vibration, and makes it the dominant component of the overall motor vibration. Finally, the correctness of the theoretical analysis and simulation results is verified through experiments on four prototypes.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"8204407-8204407"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inductive Generation of Rotation-Free Electric Fields and Non-Contact Liquid Characterization Using a Vector-Potential Transformer","authors":"Jingjing Lyu;Yuji Nishio;Lucas Ollivier-Lamarque;Masahiro Daibo","doi":"10.1109/TMAG.2026.3696513","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3696513","url":null,"abstract":"This article proposes a non-contact method for liquid characterization using a vector-potential (VP) transformer. In the proposed method, a VP coil generates an electric field originating from the time-varying VP, enabling electrical interaction with a liquid sample without direct electrode contact. Unlike a conventional capacitive field produced mainly by an electric potential gradient, the present field is intended to penetrate the sample region more uniformly along the bore of the transformer. To detect the sample-dependent response, two types of secondary structures were examined: a straight secondary conductor and a VP secondary coil with a nested-solenoidal structure. The straight secondary conductor was first selected because its path is parallel to the VP, which was expected to maximize the detected voltage through the line integral of the VP. However, this configuration also allows an induced-voltage component due to magnetic flux linkage with the thin primary solenoids. To suppress this magnetic coupling, a VP secondary coil was introduced. Although the VP secondary coil produced a weaker signal, it reduced magnetic coupling and enabled sample-dependent signals to be observed with less contamination from ordinary inductive pickup. Experimental results obtained for water, ethanol, glycerol, and aqueous electrolytes showed that liquid-dependent spectral changes can be measured in both configurations. The straight secondary conductor provides a larger signal and may be advantageous in terms of signal-to-noise ratio, whereas the VP secondary coil is advantageous for suppressing magnetic coupling and external magnetic-noise pickup. These results demonstrate the feasibility of non-contact liquid characterization based on a VP-induced electric field.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"8000606-8000606"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"12/10 Switched Reluctance Motor Capable of Operating as an Induction Motor","authors":"Akira Kohara;Noboru Niguchi","doi":"10.1109/TMAG.2026.3688035","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3688035","url":null,"abstract":"In this article, a switched reluctance motor (SRM) capable of operating as an induction motor (IM) is proposed. This motor has a rotor that combines the salient poles of an SRM with the squirrel-cage structure of an IM, enabling its operating characteristics to be varied by changing the applied current pattern. The structure and operational principle of this motor are described. Finally, the N–T characteristics are computed by finite-element analysis under two types of control patterns.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"8201005-8201005"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Ni2+ Doping on Crystallization Behavior and Magnetic Properties of Gehlenite-Based Calcium Aluminosilicate Glasses","authors":"M. Majerová;M. Škrátek;A. Dvurečenskij;A. Prnová;B. Pecušová;B. Hruška;J. Maňka;D. Galusek","doi":"10.1109/TMAG.2026.3727761","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3727761","url":null,"abstract":"Studying glasses with gehlenite (Ca₂Al₂SiO₇) composition is highly attractive because they serve as an excellent, highly stable matrix for doping with luminescent or transition metal ions. They are actively studied for modern optoelectronics and biomedical applications, including LEDs and photonics; magnetic tuning; hyperthermia and cancer treatment; and high-temperature stability. In this study, the influence of Ni²⁺ doping on crystallization behavior and magnetic properties of gehlenite-based calcium aluminosilicate glasses was studied. The glasses with a gehlenite composition were prepared with different Ni²⁺ contents (0.1, 1.0, and 3.0 mol%). The glasses were prepared by conventional melt quenching. The prepared system was studied using X-ray diffraction analysis, differential thermal analysis (DTA), and a SQUID magnetometer. X-ray diffraction analysis confirmed the amorphous nature of all prepared systems. In the DTA curves of all samples, one exothermic effect was observed with a maximum in the temperature interval (1220–1320 K), which can be attributed to the crystallization of gehlenite. The maximum temperature of the crystallization peak decreased with increasing Ni²⁺ content in the glasses, indicating an increasing tendency to crystallize and lower thermal stability of doped glasses. The magnetic properties of glasses changed as the Ni²⁺ concentration increased, indicating the incorporation of Ni²⁺ ions into the glass matrix. Magnetization versus external magnetic field dependence at 300 K indicated that the addition of Ni²⁺ significantly influenced the magnetic properties of CAS glasses. First, with increasing Ni²⁺ content, the influence of the diamagnetic component decreases, and conversely, the proportion of the paramagnetic component increases. At 2 K, only the paramagnetic component of the magnetization is present; however, the influence of this component increases with increasing Ni²⁺ addition. Furthermore, the effect of crystallization on the magnetic properties of Ni-doped CAS glasses was investigated. The results will be used to shape and further process CAS glasses for magneto-optical applications.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"2200107-2200107"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149249222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Template-Dependent Textural and Magnetic Properties of Mesoporous Silica-Coated Iron Oxide Nanoparticles","authors":"E. Beňová;N. Király;P. Hrubovčák;L. Nagy;A. Zeleňáková;V. Girman;V. Zeleňák","doi":"10.1109/TMAG.2026.3723006","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3723006","url":null,"abstract":"Mesoporous silica-coated Fe₃O₄-based nanoparticles were synthesized using cetyltrimethylammonium bromide (CTAB) and PEG as structure-directing agents. Transmission electron microscopy (TEM) imaging and diffraction revealed multicore core–shell morphologies composed of crystalline iron oxide nanodomains embedded in silica. Nitrogen adsorption–desorption analysis showed that CTAB templating produced a higher surface area mesoporous structure, whereas PEG templating resulted in lower surface area with mixed micro-mesoporosity. X-ray diffraction (XRD) and electron diffraction showed reflections consistent with a cubic Fe₃O₄-type iron oxide structure together with amorphous silica. The SQUID magnetometry confirmed superparamagnetic behavior at 300 K. Modified Langevin fitting gave magnetic core diameters of approximately 8–10 nm, in agreement with TEM. The decrease in mass-specific magnetization after silica coating is attributed to dilution by nonmagnetic silica. The results show that template selection controls pore architecture while retaining magnetic responsiveness.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"2301305-2301305"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149249224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved Method for Electromagnetic Analysis of Axial-Flux Permanent-Magnet Motor With 3-D Leakage Flux in Overhang Structures","authors":"Jun-Won Yang;Tae-Seong Kim;Chang-Woo Kim;Yong-Joo Kim;Kyung-Hun Shin;Jang-Young Choi","doi":"10.1109/TMAG.2026.3694365","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3694365","url":null,"abstract":"In this study, an improved analytical technique for axial-flux permanent-magnet (AFPM) motors is proposed, considering overhang and end leakage flux effects. To account for leakage flux at permanent magnet ends and overhang effects, flux coefficients are determined through the magnetic equivalent circuit (MEC) method and incorporated into the subdomain method. The accuracy of this improved analytical technique is verified by comparing the results with those obtained from 3-D finite element analysis. The proposed method achieves a balance between computational efficiency and accuracy, providing an effective method for AFPM motor design and analysis.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"7002006-7002006"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149249293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reactive Spark Plasma-Assisted Processing of Powdered RNi₂ Magnetocaloric Compounds (R = Dy, Tb)","authors":"R. U. Pérez-Batalla;K. Padrón-Alemán;J. L. Sánchez Llamazares","doi":"10.1109/TMAG.2026.3684214","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3684214","url":null,"abstract":"Single-phase powders of the magnetocaloric Laves phases DyNi2 and TbNi2, synthesized by arc melting, were homogeneously mixed in a 35:65 ratio and consolidated using a fast reactive spark plasma sintering (SPS) process. X-ray diffraction, energydispersive spectroscopy (EDS) mapping, and thermomagnetic analyses confirm that, within a short sintering time (around 6.6 min), the sintered material forms a solid solution of the precursor alloys. The resulting sample is essentially single phase, crystallizing in the MgCu2-type structure with a homogeneous elemental distribution. A Curie temperature of 30.3 K and a maximum magnetic entropy change of <inline-formula> <tex-math>$8.4~mathrm{Jkg}^{-1} mathrm{~K}^{-1}$ </tex-math></inline-formula> under a magnetic field change of 2 T were determined. These results demonstrate the effectiveness of reactive SPS as a rapid route for preparing rare-earth-based <inline-formula> <tex-math>$mathbf{R}_{{mathrm {1-x}}} mathbf{R}_{mathrm {x}}^{prime} mathbf{N i}_2$ </tex-math></inline-formula> Laves-phase solid solutions with tunable magnetocaloric properties optimized for hydrogen refrigeration technology.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"2500705-2500705"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149249409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}